FAQ

General Information (4)

What is RoHS?
RoHS stands for Restriction of the use of Hazardous Substances. Since 1 July 2006 the European RoHS directive is introduced. It involves the use of lead, cadmium, mercury, hexavalent chromium, PBB and PBDE. The lead-free soldering is an important part of this directive. For the entire list of EU directives, click here.
Does Elfa have a RoHS certificate?
Yes. This statement confirms that the assembly workshop of Elfa is RoHS compliant. For completeness, we report here that the RoHS directives do not apply to batteries.
What is NEN?

NEN stands for National Normalization Institute. Who participates in normalization, shares his/her knowledge with others in order to gain a collective advantage. Normalization aims for efficient, safe, healthy and sustainable products and processes. In a smart way, multiple interests are united. The Dutch National Normalization Institute works towards economic growth and welfare on both European (CEN, CENELEC and ETSI) and worldwide scale (ISO, IEC and ITU).

Click here for the website of NEN.

What is meant with removal contribution?
For all products that include a battery, a mandatory disposal fee must be paid to the Stibat. This is in line with international regulations regarding the environment. Batteries can be returned to the municipal or regional chemical waste depots or other collection channels. Batteries used for commercial purposes can be handed to licensed collectors.

Button batteries (13)

What is a button battery?

A button battery is a round battery whose diameter is larger as its height. Sometimes they are so small that they look like a button or knob. That is the main reason why they are called button cells.

What is a button battery user for?

There are a lot of applications. The most important are watches, cameras and hearing aids. In addition, there are calculators, games and auto alarms.

What kind of button batteries are there?

Various systems exist. The properties are matched to the key applications.

System Application Properties
Silver oxide Watches and cameras High constant voltage, Self-discharge less than 5% per year
Alkaline Electrical appliances Delivers high currents, Voltage drops during use, Self-discharge less than 3% per year
Lithium Cameras and electronic devices Self-discharge less than 1% per year, Not suitable for heavy load
Zinc air Hearing aids High capacity, Self-discharge of 3% per year (if not enabled).
Mercury oxide Electrical appliances, hearing aids and cameras Delivers high currents, Self-discharge of 2% per year, Environmentally unfriendly (15% mercury)

Mercury-containing batteries are no longer produced since 1998 and are no longer supplied by manufacturers since 1999. Zinc air batteries replaced a small number of these mercury-containing cells.

Why do watch batteries always contain silver oxide?

The voltage of this system is high and constant. Time must always be reliable, hence this battery type.

What are the specific features of alkaline button batteries?

They can deliver high currents because their start voltage is 1,5V. However, the voltage decreases strongly over the usage period. Therefore, these batteries are less suitable and reliable for cameras and measuring equipment.

Why do lithium button batteries last so long?

Lithium batteries last very long (sometimes ten years), even if they are hardly used. Annually the self-discharge is only 1% of its capacity.

Why is a sticker stuck on zinc-air batteries?

When the sticker is removed from the battery the cell will be activated. This will result in oxygen penetrating through the holes in the battery. Because the active material comes from outside the battery, there is more space left in the battery for a higher capacity level. Thus these batteries have a long life time and a flat discharge curve.

Can button batteries withstand high and low temperatures?

The maximum allowable temperature for button batteries is between -10°C and +65°C. However, the best working environment is between +10°C and +35°C.

Do rechargeable button batteries exist?

There are several types of rechargeable button batteries. These batteries are often built into the devices. However, in consumer stores, they are rarely available, partly due to the low demand.

Where can I find the positive and negative pole on a button battery?

The negative pole is at the top and the positive pole is at the wider bottom of the battery. The plus pole usually provides information about brand and the model number of the battery. This side of the battery is almost always on top when inserting into a device.

How do I know which hearing aid battery is required?

The different types of hearing aid batteries are identified by the sticker on the battery pack. These batteries are packed in a blister of 6 pieces.

Battery Colour Application
5 red Mini hearing aids in the ear canal
10 yellow Mini hearing aids in the ear canal
13 orange Hearing aids behind the ear and in the ear shell
312 brown Hearing aids in the ear canal
675 blue Hearing aids behind the ear
How long do hearing aid batteries last?

This depends on the type and the intensity of use. In general, the larger batteries of the type 675 last up to two weeks, while the smaller batteries (5 and 10) only last for a few days.

Do rechargeable hearing air batteries exist?

Yes, but these rechargeable hearing aid batteries are not interesting for the end users. The useful life is so short that the user must replace it with a recharged battery several times a day. For example, there is a 675 NiMH battery of 1,2 volts and 40 mAh, however this battery will need to be recharged after a period of 8 hours.

Lanterns & Lighting (9)

What is LED lighting?

LED stands for Light Emitting Diode, and is seen as the lighting system of the future. This type of lighting can be seen as the successor to incandescents. Incandescents have the disadvantage that the filament burns out after a certain period of time. For LEDs this is not the case, because these lamps don’t use filaments but convert electricity directly into lighting. This ensures much less power is needed in order to create lighting.

The advantages of LED in a glance:

  • Very economical with power: a lot of light for less energy.
  • An extremely long product life (20.000 – 100.000 hours).
  • Resistant to vibration because it does not make use of the sensitive filament.
  • Can handle temperature differences.
  • Different lenses can be used to adjust the lighting beam.

The disadvantages of LED in a glance (especially with older LEDs):

  • Low light output.
  • The lighting colour tends to be blue.
What are the differences in fittings?

There is a large variety of fittings available that can be applied to different types of lamps. Below you can find the most common ones:

  • Screw fittings: The best known are the small (E14) and the large (E27) fittings. In addition there is the Goliath-fitting (E40).
  • Insertable fittings: In this case the lamp has one or multiple bases that can be inserted into the fittings. The bases can usually be placed automatically in the fittings, however, sometimes they need to be screwed to put them in place. Insertable fittings can be purchased in both small and large sizes.
  • Fluorescent fittings: All straight fluorescent tubes have their own unique fitting system.
  • Bayonet fittings: The type of fitting is pushed into the lamp so the pins (attached to the fitting) can firmly be clamped to the side.
What is a light bulb?

A light bulb consists of a vacuumed or with glass-filled glass bulb with a filament. When power flows through the filament, this will glow and emit light. There are various bulb types for different applications. Which bulb type will be used depends on the kind of gas is added to it. In general, we speak of three types of bulbs: the ‘normal’ (krypton) bulb, halogen bulb and xenon bulb.

  • Krypton bulbs: 90 to 95 percent of the power this light bulb uses is converted into heat. This means that only 5 to 10 percent of the energy is actually transformed into light. A light bulb is net very efficient and have a lifetime of approximately 1.000 hours.
  • Halogen bulbs: A halogen lamp is a type of light bulb that gives extra lighting thanks to the extra halogen gas it contains. This bulb type will also last longer compared to a krypton bulb and consumes up to 30% less energy for some applications. Halogen bulbs are more expensive to purchase, because they have a higher light output and an excellent colour reproduction. Furthermore, the performance of halogen bulbs is constant over their entire lifetime and is often smaller compared to regular light bulbs.
  • Xenon bulbs: Within xenon lighting bulbs gas is ignited. This will result in 3 times more light output compared to the regular halogen lighting bulbs. After approximately 2.500 hours of operation, the light output will be about 70%, which still is more compared to a good halogen lamp.
Where are LEDs mainly used for?

LEDs are applied in flashlights and signal lighting.

What is an ATEX certified lamp?

ATEX stands for ATmosphères EXplosives. If a lamp is ATEX certified the lamp will be suitable for use in a hazardous environment. Whether a lamp is or is not ATEX certified can be seen on the housing of the lamp, because this is engraved in the product. Elfa has a number of leading brands which are ATEX certified in its product range.

Which types of ATEX codes can be distinguished?

Whether a lamp is or is not ATEX certified can be seen on the housing of the lamp. This consists of a number of encodings. These codes and what they stand for can be defined as the following:

  • CE: This code agrees that products meet all quality requirements of the European Union.
  • Ex: The specific sign for explosion prevention.
  • G, D or GD: Applicable in gas (G), dust (D) or both (GD) atmospheres.
  • E Ex: Approved for use in explosive areas according to the latest common European requirements.
  • E ib: Degree of protection.
  • IIA, IIB or IIC: The gas group in which the product falls (IIA represents the smallest risk of ignition and IIC represents the largest risk of ignition).
  • T1 t/m T6: The temperature classification of the bulb that is used. T1 represents the highest temperature and T6 the lowest temperature.

An ATEX certification must be issued by a notified body, such as KEMA or DEMKO. If the lamp is assessed by a non-certified testing institute the zone in which the certification is granted will be a maximum of 2. This is the lowest protection class/zone.

What does ATEX stand for?

ATEX stands for ATmosphères EXplosives. An explosive atmosphere is defined as following: a mixture of flammable substances in the form of gases, vapour, mists or dust under atmospheric conditions, in which the combustion will spread to the entire mixture after ignition.

Since July 2003 ATEX 95 and ATEX 137 are introduced. These guidelines are written specifically to focus on safety in explosive environments and to set legal obligations to the use of explosive-proof products in these hazardous environments.

Which types of ATEX zones can be distinguished and what do they mean?

ATEX talks about danger zones. The atmosphere and the prevailing condition in the workplace are crucial for installation methods of the used materials and the choice of equipment. Therefore, it is important to make a zone classification of areas that might be dangerous (for the purpose of gas- and explosion hazard). These potential dangerous areas are based on the frequency and the duration of an explosive atmosphere:

  • Zone 0, 1 and 2: at risk of a gas explosion (a mixture of flammable gas and vapour or mist).
  • Zone 20, 21 and 22: at risk of dust explosion (a cloud of flammable dust).

The lowest number indicates the most dangerous zone. As the danger zone becomes heavier, the stricter the demands become on the design of the work environment, the application, the use of equipment and security systems.

Where can I find more background information about ATEX?

There is a lot of information available on ATEX zones. Below some interesting websites are listed:

Non-rechargeable batteries (8)

What types of non-rechargeable batteries are there?

The better types of non-rechargeable batteries are called alkaline batteries and the cheaper kinds are called zinc-carbon batteries. Alkaline batteries last considerably longer and are better suited for devices that require a lot of power. Moreover, alkaline batteries are leak-proof. The improved zinc-carbon batteries, also known as zinc chloride, have an additional protective jacket to prevent leakage.

Do alkaline batteries last five times longer?

Yes, but only if you compare the best alkaline battery to the worst zinc-carbon battery. In addition, there must be an unusual situation in which the device is turned on continuously. So it can be said that this is an exaggerated claim. In most cases, it is recommended to choose for alkaline batteries, because they go along considerably longer. The capacity of a modern alkaline AA battery lies between 2.600 and 2.800 mAh, while a zinc-carbon AA battery has a capacity of approximately 1.000 mAh.

When are zinc carbon batteries interesting?

Devices with low power needs, such as clocks and thermostats, don’t require an expensive alkaline battery. Zinc-carbon batteries have the characteristic of recovering somewhat after being used. You can see this, for example, when turning of a flashlight after having used it for a long period of time. The light beam becomes weaker after using the flashlight for a consecutive period. However, the light beam becomes better when you turn of the flashlight. An alkaline battery has a more gradually decreasing voltage curve, but will last for a longer period of time.

How do I recognize sizes of batteries? And what abbreviations are there?

Different battery sizes have a specific name and may also have a unique code. The battery names are the same in all countries across the world (although many other terms are used frequently). However, the battery codes show great differences. For example, there are international IEC and American codes for different battery sizes.

In addition, manufacturer of specific batteries often use their own codes for the produced products. Therefore, it is difficult to recognize certain codes on battery packages. The IEC code is the most common of all. The battery types can be identified by the different letters in the IEC code. For example, alkaline batteries are called LR and zinc-carbon batteries have the letter R as first letter in the IEC code.

IEC-code US-code Name Popular terms Dimensions(mm)(diamtr x height)*
LR1 N Lady    
(L)R03 AAA Micro small penlite, pencil cell 10,5x44,5
(L)R6 AA Mignon Penlite 14,5x50,5
(L)R14 C Baby English bar, small bar 26,2x50
(L)R20 D Mono Big bar 34,5x61,5
R25   Block battery    
6(L)R61 E 9 Volt E-block 26,5x17,5x48
3(L)R12   Normal Flat 4,5 Volt battery 26x22x67
*Tolerance differences may exist.
What battery abbreviations are there?

Below you can find the standard abbreviations for the various battery systems. These are the universal terms that also can be found in the product catalogue. The table makes a distinction between round (R) and flat (F) batteries. The P stands for all batteries that are not round.

B = Lithium carbon monofluoride (low drain) BR
C = Lithium mangaan dioxide (high drain) CR
E = Lithium thionyl chloride ER
F = Lithium iron disulfide FR
G = Lithium Copper oxide GR
K = Cadmium KR
L = Alkaline LR
M = Mercury MR
P = Oxygen PR
S = Silver SR

LR batteries are thus round alkaline batteries and flat alkaline batteries would thus be LF batteries.

Can alkaline batteries be recharged?

No, normal alkaline batteries can’t be recharged. However, there are rechargeable alkaline batteries, but these have several big disadvantages:

  • Firstly, you will need a special charger which usually is very expensive. Recharging alkaline batteries with a charger, intended for rechargeable nickel-hydride or nickel-cadmium batteries, can be very dangerous (risk of explosion).
  • Secondly, the voltage of an alkaline battery may fall below a critical point, in this situation they can’t be recharged anymore. The problem is that you don’t know when this critical point will occurs. This means you will need to recharge the batteries, which is a disadvantage if you want to use them for a prolonged period of time.
  • Thirdly, the batteries will never gain their full capacity after being recharged. If the battery has been used several times, the available energy quickly becomes less. In practice you can recharge these batteries only a few times. However, the net efficiency of these batteries is very low.

Because of these disadvantages, it is recommended to buy the official rechargeable batteries. The only advantage in using rechargeable alkaline batteries is the higher initial voltage rate. However, this voltage rate drops rapidly to a point even lower that that of an official rechargeable batteries (NiCd/NiMH).

What should I know about air alkaline batteries?

A distinctive system within the different types of primary batteries is air-alkaline. This battery type uses oxygen (O2) from the air as the cathode. In an electrical system with two poles or electrodes we speak of cathode for the pole where the electrons go in. The oxygen is fed to the cathode through the small holes in the housing of the battery, where reduction (absorption electrons) occurs on a carbon layer. In the battery housing only an anode has to be enclosed. This will result in an energy density per weight between 220 to 300 Wh/kg on average (compared to 99 to 123 Wh/kg of a silver-oxide battery). An additional advantage of this battery type is the relatively low cost and its environmentally friendly nature. These batteries have an infinite shelf life, until they are exposed to air which will activate them. After activation, the shelf life will become relatively short due to the high self-discharge rate. Another drawback: once activated, the chemical process of energy production is unstoppable; however, it can be slowed down.

Air-alkaline battery applications:

  • Railway signal lighting
  • Roadwork signal lighting
  • Buoy lighting and signal lighting at sea
  • Telecommunication
  • Parking meters
  • Fence lighting
What should I know about lithium batteries?

Lithium batteries are characterized by a very low self-discharge rate. Annually the self-discharge is only 1% of the battery capacity. The voltage of this battery type is exceptionally high. On this information sheet different brands and product variants of lithium batteries are mentioned. Lithium is a light metal with an exceptional high capacity (3,86 Ah/gram). When lithium is mixed with other chemicals, such as manganese or sulphur, this will result in a battery containing a lot of energy, low weight, reduced self-discharge and the ability to perform under extreme conditions.

Lithium battery applications: Lithium is used for many applications, such as mobile phones, microprocessors, within industrial situations as in the oil and gas industry and finally in aerospace applications.

Rechargeable batteries (16)

How does a rechargeable battery work?

You can compare the operational features of a rechargeable battery to that of a car battery. If it becomes empty, it can be recharged and reused again. With optimal treatment, these batteries can be recharged up to a thousand times. Due to the constant voltage rate (1,2 Volt) the rechargeable battery will provide a stable power source from the beginning to the end. Rechargeable batteries suddenly die and from that moment on will not work any more unless they are recharged again.

What are the main benefits of rechargeable batteries?

Rechargeable batteries have a long shelf life and can be recharged up to a thousand times. They are more expensive to purchase compared to non-rechargeable alkaline and zinc carbon batteries, but if you use batteries on a regular basis the investment made will be earned back very quickly. For example, you don’t need to purchase non-rechargeable batteries any more. Furthermore, rechargeable batteries reduce the amount of waste which will have a positive contribution to the environment.

Is a rechargeable battery of 1,2 Volt usable for all application?

Yes. However, alkaline batteries have a voltage of 1,5 in the beginning, but this quickly drops after a period of time (even below the level of a rechargeable battery). In contrast rechargeable batteries have a very stable voltage variation over the used period of time.

What are the main disadvantages of rechargeable batteries?
  1. Rechargeable batteries suddenly die and from that moment on will not work any more unless they are recharged. With alkaline batteries the power flows out of the battery more gradually. In this case you see when the batteries need to be replaced in advanced.
  2. Rechargeable batteries are more expensive compared to alkaline batteries (also because you need to buy a charger).
  3. Rechargeable nickel-cadmium batteries contain for 15% of the heavy metal cadmium. However, these batteries can be recycled excellently.
  4. Nickel-cadmium batteries have the drawback that you need to fully discharge them before they can be recharged again. If you don’t do this a memory block will arise and the battery can no longer be recharged to its maximum. However, NiMH batteries don’t have any problem regarding the memory block and can therefore be recharged at any time.
Why does a rechargeable battery suddenly die?

The voltage of a rechargeable battery remains pretty constant during use, but when the battery is empty, the voltage drops very quickly. This voltage downfall is much faster compared to an alkaline battery, which gradually leads to its end.

Which applications are most suitable for rechargeable batteries?

For devices that require a lot of energy in a short period of time, such as portable cassettes and CD players, portable radios, electronic toys, motorised toys, household appliances, professional and digital cameras, video cameras, mobile phones, portable computers, and many other professional devices. Rechargeable batteries are not recommended if the device is hardly used (read the manual of the device and indications in the battery compartment). Some fact you should take into account:

  • Rechargeable batteries can suddenly get empty when you don’t use them.
  • Rechargeable batteries losses 1% of its power every day due to the self-discharge.
Can rechargeable batteries be reloaded over a thousand times?

Yes. However, in practice rechargeable batteries are often handled careless and will not meet the thousand recharge cycles. Especially with nickel-cadmium batteries this poses problems because they are not fully discharged first. In addition, empty batteries stay empty for a long period of time, because people tend to recharge them only when needed. Keeping batteries empty or half empty for a long period of time has a negative effect on rechargeable batteries and will damage them in the long run.

Can rechargeable batteries withstand high and low temperatures?

In extreme weather- and operating conditions (below -20°C or above +55°C) rechargeable batteries work significantly better compared to alkaline batteries.

What is a nickel metal hydride (NiMH) battery?

The current generation of rechargeable batteries, in which the environmental harmful cadmium is replaced by a metal alloy, is able to absorb energy in the form of hydrogen (hydride). Thanks to this hydrogen nickel-hydride batteries contain a much higher amount of energy compared to other types of rechargeable batteries.

What are the main advantages of NiMH batteries versus NiCd batteries?
  1. Nickel-hydride does not contain heavy metals (15% vs. 0% cadmium in nickel-cadmium batteries).
  2. Up to 200% more capacity compared to nickel-cadmium batteries of the same size. For example, a nickel-hydride penlite (AA) has a capacity of up to 2.100 mAh.
  3. There will be no memory effect and the unused capacity will always be available. You can now recharge the battery at any time, without loss of capacity.
What does the memory effect actually mean?

If you recharge a NiCd battery before it is completely discharged, crystals will arise on the electrodes of the battery. The more often you do this, the thicker the layer of crystals will become. The result is that the amount of available energy will become smaller. You can pep-up/excite/stimulate these batteries by discharging them several times by using an electronic discharge device. Rechargeable NiMH batteries do not have any problem with this so-called memory effect and can be recharged at any time.

What type of NiMH batteries exist?
  • AAA cell batteries (750 and 800 mAh).
  • AA cell batteries (1.700 and 2.100 mAh).
  • C cell batteries (2.900 mAh).
  • D cell batteries (2.900 mAh).
  • E-block batteries (150 mAh).
  • Battery packs for video cameras, digital cameras and mobile phones.

Depending on the type, these batteries provide up to 200% more energy compared to similar types of nickel-cadmium.

Can NiMH batteries be recharged in any type of charger?

Due to the relatively high capacity of nickel-hydride batteries, they can best be recharged in nickel-hydride chargers. These chargers have a high charging current and can, therefore, recharge the batteries quickly. If the batteries are recharged in a nickel cadmium charger it may happen that the batteries will not be fully recharged. Nowadays there are high-quality chargers available that are suitable for both NiCd and NiMH batteries.

What is a rechargeable battery-pack?

These are large rechargeable batteries, which are made up of a number of smaller batteries. They are used for video cameras, mobile phones, laptops and industrial devices. The battery packs have a higher voltage and capacity, because smaller batteries a stuck to each other. For example, 6 penlites (AA) of 1,2V – 1.100 mAh placed in a serie provide a pack of 7,2V – 1.100 mAh. The same 6 penlites placed in a parallel position provide a pack of 1,2V – 6.600 mAh. Battery packs are often developed for particular devices.

What should I know about lead acid batteries?

The lead battery/accumulator is designed for applications that require high currents. One needs to recharge lead acid batteries as much as possible, otherwise they become obsolete. The lead acid batteries are especially suitable for industrial applications. In general, one can speak of the following types of lead-acid batteries: start, traction and standby (classic), SLA / VRLA / AGM and gel batteries.

  • Start, traction and standby (classic): Start batteries should be able to deliver a large amount of power for a very short period of time (a few seconds). Traction batteries on the other hand are used in activities where deep discharges are involved and where the battery must be recharged every day. Standby batteries are designed for ‘no-break’ applications, and often serve as backup power. The disadvantage of these conventional lead acid batteries is that they work with liquid electrolyte. As a result, the batteries must be assembled in an upright position to avoid the risk of leakage. The system thus seems somewhat out of date.
  • AGM (Absorbed Glass Mat): These batteries are designed for applications in which a large standby current is required. The liquid electrolyte is packed in a special glass fibre separator. More than 99% of the generated gas is recombined. Therefore, the battery is maintenance free. The battery can be mounted in different positions (even upside down).
  • Gel batteries: In these types of batteries the electrolyte is provided in gel form, instead of liquid. The battery is especially suitable for cyclic applications and is able to provide higher currents compared to the AGM batteries. In addition, this battery type is completely maintenance free and can be stored both fully charged and discharged.
  • Spiral technology: A technique that can’t be left unnoticed is the spiral technology. This system is build upon the system of pure lead technology. Instead of using flat plates, as in conventional batteries, use is made of two lead plates that are wrapped in a spiral cell. The insulator is made of glass fibre in which the electrolyte is absorbed. Through the use of lead in combination with a special production technique a compact battery arises with a very high performance level.

Lead acid battery applications:

  • Classic: medical equipment, agricultural products, electronic forklifts.
  • AGM: aircrafts, defence systems. Electronic vehicles.
  • Gel: electric vehicles, alarm systems, medical equipment.
  • Spiral: aerospace, medical devices, critical applications.
What should I know about lithium batteries?

This is the latest technology in the field of rechargeable batteries. The lithium rechargeable battery has a tremendous energy density. The volume is much smaller and lighter compared to NiMH batteries and the voltage of a lithium battery is much higher (3,7 Volt). Furthermore, the self-discharge is not high and does not damage the battery in case of prolonged overload. Two types of rechargeable lithium batteries can be distinguished:

  • Lithium-Ion. This technology doesn’t make use of lithium metals for the negative electrodes. Instead, carbon is used that absorbs lithium ions. This system is much more environmentally friendly compared to other rechargeable batteries. For example, this battery type doesn’t make use of toxic substances such as cadmium, lead or mercury.
  • Lithium polymer. This type of battery makes use of a gel substance and is mainly used in small electronic applications. The high energy density, low self-discharge, but in particular the voltage of 3,7V make lithium polymer batteries superior compared to other rechargeable battery systems. The capacity of a lithium polymer cell depends on what type and brand of battery is concerned, but this varies roughly between 300 mAh and 8000 mAh. In terms of equipment, these batteries should be charged with special chargers. The regular NiCd/NiMH chargers are not suitable for recharging these battery types.

Applications of lithium rechargeable batteries:

  • Photo and video equipment
  • Laptops
  • Mobile phones

Batteries and accumulators (29)

How does a battery work?

A battery is a cell that, by means of an internal chemical reaction, can relinquish electrical energy. The cell consists of a positive and a negative pole, which are separated by a layer of electrolyte. The negative pole is brought into contact with the positive pole via the device in which the battery pack is placed and will generate electricity.

What is the difference between disposable (primary) and rechargeable (secondary) batteries?

For both single and rechargeable batteries chemical reactions are created within the batteries system, which result in an electric current. The main difference is that rechargeable batteries can convert electrical energy, obtained form the outlet, into chemical energy, this can be done about a thousand times. The rechargeable battery is also called secondary battery (two-way energy); while a single battery in technical terms is called a primary battery.

What is the difference between dry and wet batteries?

A dry battery (or accumulator) is fully sealed and maintenance free. Whether you hold the battery straight or upside down, it always provides energy. A wet battery (or accumulator), however, contains a liquid (electrolyte), which eventuates if you don’t keep the battery in a straight position. Such batteries are often not fully closed/sealed and are not maintenance free. Nowadays, only batteries for industrial applications are made in wet version. The batteries meant for the consumer market are all made in the dry version.

Does the capacity rate of a battery have an influence on its durability?

Yes, the higher the capacity, the longer the battery lasts. The capacity is expressed in ampere hours (Ah) or milli-ampere hour (mAh). You can usually find information about the capacity in batteries on packaging and batteries themselves.

What does internal resistance of a battery mean?

Specific (chemical) systems can more easily flow energy compared to other systems. Both voltage (V) and internal resistance (ohms) are important for a batteries performance. You can compare the internal resistance of a battery with a tap where water flows through. If the internal resistance is low, there will flow a lot of water through the tap. If the internal resistance is high, this will work the other way around. This is also comparable with the difference between a big and a small tab. Battery types with a low internal resistance are respectively nickel-cadmium, nickel-hydride, alkaline, photo lithium and mercury oxide. Battery types with a high internal resistance are respectively lithium, zinc air, silver oxide and zinc carbon.

What does mAh mean?

The capacity and thus the lifetime of a battery depends on the power current, expressed in thousandths of Amp (Ah), or milli-amperes (mAh) multiplied by the number of hours that the battery can provide power. You can compare this with a barrel of water with a tap attached to it. The further you turn the tap open, the faster water will drop out of the barrel. The number of hours indicate how long it takes before the barrel (the battery) is empty.

Why do batteries have different voltages?

Between the positive and negative terminals of a battery voltage exists. Since the flow between both poles runs through the device, the product must be adjusted to a certain voltage; otherwise the unit will not work. The most famous batteries are the 1,5 Volts. Some deviate slightly from this battery type. Especially with button batteries (e.g. lithium 3V) the difference in voltage is of influence on the malfunction or failure of the device. For rechargeable batteries, which have a lower voltage, this is not a problem. A similar alkaline battery (non-rechargeable) begins with 1,5 volts, but this will drop below 1,2 volts after some time of use.

Which battery has what voltage?

Lithium (block)battery 6V -> (Digital) cameras

Lithium button battery 3V -> Calculators

Silver oxide button battery 1,55V -> Watches

Alkaline dry battery 1,5V -> Audio, cameras, toys

Alkaline button battery 1,5V -> Elektronic games

Zinc carbon dry battery 1,5V -> Clocks, alarm clocks, flashlights

Zinc air button battery 1,4V -> Hearing aids

Mercury oxide button battery 1,35V -> Cameras, hearing aids

Nickel-cadmium rechargeable 1,2V -> Audio equipment, toys

Nickel-hydride rechargeable 1,2V -> Audio equipment, toys, digital cameras

How long does a battery provide power?

This is highly dependent on the type of device being used. For example, you have a blister of 6 alkaline penlite (AA) batteries with the following specifications: 1,5V and 2500 mAh. The fist set of batteries are put into a wall clock, which will provide power for probably two years. These two years consist of a total of 17.520 hours. Counting backwards, the clock consumes less than 0,15 milliampere per hour (mAh). However, in reality, this is incorrect as factory specifications suggest the timepiece consumes 1 mAh. Both the stable power consumption and environment temperature contributed to the extended performance. The second set of batteries is put into a small radio that consumes 300 mAh. If the radio is turned on continuously, it probably would provide eight hours of music. When turning down the volume the batteries will last longer and when turning up the volume this works the other way around. The last set of batteries go into a flashlight with a 1,5; 1,0 Watt bulb. If the lamp is let continuously the batteries will die within approximately 3,5 hours.

What is energy?

Energy is voltage (V) x capacity (mAh). The amount of energy that a battery provides is not equal to the useful life (capacity), because the voltage level also determines how much energy a battery can deliver.

What is the approximate capacity of a battery?

The amount of power in a battery depends on two factors: the voltage (V) and the internal resistance (Ohm). As a result, the power of a battery is determined by on the one hand the possibility to be able to provide a given energy source, and on the other hand the possibility to be able to provide a certain amount of power. Therefore, power is the possibility to be able to supply high currents within a short time, without overheating the battery.

What causes a short-circuit?

If the positive and negative terminals come into contact with each other a short-circuit occurs. As a result, the battery then no longer works. A short-circuit should be avoided because the high internal pressure will cause gas release. Eventually, there is a chance the battery will explode.

Are the used metals implemented in the battery name?

Usually not. There has never been a real standardization from the start of the battery production. Moreover, it is often the case that both poles consist of multiple materials. With rechargeable nickel-cadmium batteries, it happens to be clear: both the positive and negative pole are made of nickel-cadmium. But in most batteries only the chemical elements are mentioned, such as alkaline, lithium, etc.

Can batteries be stored in the refrigerator?

Yes, in principle this is a very good method to counteract self-discharge. However, batteries must be kept dry at all times. To prevent moisture (condensation) comes inside the battery, they have to be kept in an airtight container in the refrigerator. If they are then taken out of the fridge, they must first acclimatize before taking them out of the airtight container.

Can modern batteries leak?

Leaks were formerly an annoying effect of the cheaper zinc-carbon batteries that were mostly produced until the seventies. When using this type of battery, the zinc casing of the battery was eaten by the performed chemical reactions within the cell. In the eighties, manufacturers introduced an upgraded version of zinc-carbon batteries on the market (a double zinc cup against leaks) and a new form of electrolyte that caused crystallization instead of leakage. During this period of time the alkaline battery was also introduced on the market (other structure and chemical composition). Nowadays producers only bring alkaline and the improved carbon zinc batteries on the market. Rechargeable batteries naturally don’t duffer from leaks. However, it remains advisable to make sure that batteries are not exposed to extremely high temperatures.

What is the shelf life of a battery?

Batteries have a so-called self-discharge. Even if a battery is not used, eventually energy will be lost. The degree of self-discharge is influenced by both internal and external factors, such as weather conditions, storage conditions and battery types. Alkaline batteries have a shelf life of approximately 5 years (self-discharge approximately 2-4% annually) and zinc carbon batteries about 2 years (self-discharge circa 4-6% annually). Lithium batteries have a very low self-discharge and can, therefore, be kept longer. Rechargeables have a very high self-discharge of 1% per day, but can be recharged when desired. Rechargeable button batteries, finally, have a self-discharge rate of approximately 0,1% per day.

Can batteries be used in all temperature conditions?

When batteries become extremely cold, they work less well in general. Various batteries types consist of so-called electrons, which move more slowly when it becomes colder. Eventually, this will result in a power failure as the electrons can’t move within the battery. In extreme warm/hot circumstances, the self-discharge increases. It has to be taken into account that one battery type is more resistant to extreme weather conditions compared to others.

Which safety aspects need to be taken into account?
  • Always place plus pole to the plus terminal and minus pole to the negative terminal of the device.
  • Never open batteries.
  • Do not weld or solder batteries by yourself.
  • Never throw batteries into fire.
  • Never throw batteries into water.
  • Don’t store batteries in humid areas, such as a refrigerator, unless they are packaged airtight.
What is the application area for non-rechargeable batteries?

The most important applications are often displayed (in the form of icons) on the packaging of products, such as portable radios, walkmans, camera’s, toys, clocks, alarm clocks, dictation machines, remote controls and flashlights. In addition, there are countless other products that work on one-off batteries. In some of the products mentioned rechargeable batteries can also be used.

Why have mercuric oxide batteries disappeared from the market?

Although mercury batteries were characterized by relatively high voltages and a low internal resistance, they contain 30% of the environmentally harmful heavy metal mercury. Therefore, it has been decided to discontinue the global production of these battery types. In contrast, for a small number of these batteries a replacement zinc air battery entered the market.

Equipment is getting smaller, does this also apply to batteries?

Yes, especially if you look at the changes occurred in the last ten years. The well-known dry batteries penlite (AA), and pencilcel (Micro AAA) are becoming increasingly popular. The larger types, Baby (C) and Mono (D) are not used as frequently as in the past. In addition, new developments have ensured that a larger amount of power can be stored in smaller packaging (NiMH and Li-ion). Button batteries are also undergoing revolutionary changes: for example, the 0,5 mm thick credit card batteries.

Which batteries will dominate in the future?

This is hard to predict, but changes are already rapidly emerging. WAP mobile phones, media and multimedia devices, screen television, mobile videophones, all of these products have the need for portable energy fuelling. Lithium-ion technology is in an infancy stage. However, it is already known that new developments in the battery industry will emerge on the market within a few years.

Will there be new battery types in the near future?

Lithium-ion (Li-ion) is the latest/newest technology used in batteries. These are rechargeable batteries that contain significant amounts of energy within a small space. The energy density is 50% higher than that of a NiMH battery. Although the capacity is relatively low, the battery voltage is extremely high. The Li-ion batteries are mainly processed within laptops, mobile phones and digital cameras. Because Li-ion technology still is relatively expensive, it remains to be seen whether this battery type also will come to the consumer market in standard versions.

What batteries types will be sold most frequently in the future?

Penlites and other common batteries will continue to be purchased by consumers in supermarkets, department stores, drugstores and web shops. The professional users purchase their batteries through combined purchasing or wholesalers. Specialty stores, camera stores, electronic stores, telecommunication stores and computer stores, for example, will remain market leader in the segment of rechargeable batteries because of their specific discipline. The small button batteries will probably remain the specialiy of photo specialty stores.

Will batteries be consumed more/less frequently in the future?

It is expected that with the increase of mobility, the consumption of portable energy will continue growing as well. However, it has to be taken in consideration that the growth will be less in non-rechargeable batteries compared to the rechargeable batteries.

What is the definition of smart batteries and will these battery types appear on the market?

Yes, batteries equipped with a chip. As a result, these batteries don’t only supply energy but also control the main features of devices. There are already batteries available on the market on which you can see how much power still is in it. In the near future it will also be able to see how often a battery is recharged, when was the last time it was recharged, what its temperature was during the recharge, etc.

Will alternative portable energy sources be introduced in the future?

The alternatives are limited. For the memory function of various devices (laptops, palm computers, etc.) so called E? Proms can be used. Nowadays these mini chips are very expensive. However, a battery will still continue to power these devices, even with solar sources. The conclusion is that batteries will remain as the main source of portable power for the coming decades.

How long does a battery provide power?

This is highly dependent on the type of device being used. For example, you have a blister of 6 alkaline penlite (AA) batteries with the following specifications: 1,5V and 2500 mAh. The fist set of batteries are put into a wall clock, which will provide power for probably two years. These two years consist of a total of 17.520 hours. Counting backwards, the clock consumes less than 0,15 milli ampere per hour (mAh). However, in reality, this is incorrect as factory specifications suggest the timepiece consumes 1 mAh. Both the stable power consumption and environment temperature contributed to the extended performance.

The second set of batteries is put into a small radio that consumes 300 mAh. If the radio is turned on continuously, it probably would provide eight hours of music. When turning down the volume the batteries will last longer and when turning up the volume this works the other way around. The last set of batteries go into a flashlight with a 1,5V, 1,0 Watt bulb. If the lamp is let continuously the batteries will die within approximately 3,5 hours.

What general concepts have to be taken into account?
  • Voltage. Voltage is the name for electric current. It is the unit of measure for power that comes out of a battery, expressed in amperes. Every battery has internal resistance. This is a component where electrons can flow through difficult.
  • Ohm’s law. The relationship between a battery its current, voltage and resistance is summarized in the following formula: I = U: R (ie: Current = Voltage: Resistance). A battery its current becomes higher as the voltage increases or when the resistance decreases.
  • Capacity. The reported capacity is the maximum current that can be withdrawn at a constant discharge rate. The higher the capacity of a battery, the longer its life time. The capacity is expressed in ampere hours (Ah) or in milli ampere hours (mAh). The battery pack provides information on the amount of available capacity a battery consists. The capacity and thus the lifetime of a battery depends on the current expressed in thousandths of amperes (Ah) or milli amperes (mAh) multiplied by the number of hours (h of ‘hours’) that the battery can provide power.
  • Storage conditions. The most ideal conditions for storage of batteries are the following: an environment temperature below 18ºC and humidity rate less than 50%. When the environmental temperature exceeds 18ºC the chance of self-discharge increases. At a humidity rate above 50% the risk of corrosion will increase.
  • Start, traction and standby. These are batteries that are placed in the lead battery category (a special type of battery system):

    - Start batteries should be able to deliver a large amount of power for a very short period of time (a few seconds). Therefore, it is necessary that the battery cells have a large surface that comes into contact with the acid inside the battery. Situations in which these are used are, for example, agricultural products.

    - Traction batteries are used in activities where deep discharges are involved and where the battery must be recharged every day. These are often used in shipping and electric vehicles.

    - Standby batteries are designed for ‘no-break’ applications and often serve as backup power. These batteries are characterized by a very low self-discharge.

  • Solar technology Technology in which the battery is recharged by sunlight. By installing a solar panel to the battery, energy can be extracted from the sunlight to recharge it. The amount of electric power a solar panel can supply is determined by the cell material, its position and its surface. One square meter of solar panel can produce roughly 100 watts of electricity (6A). However, the larger the surface area of a solar panel, the more electrical output can be produced.
  • High drain and low drain batteries. High drain and low drain are actually English designations for high current and low current. What determines whether a battery emits high or low currents? This has to do with the internal resistance of the battery. When the battery has a high internal resistance, it can not provide high currents (low drain batteries). Batteries with a low internal resistance are able to deliver high currents and thus are high drain batteries.

Chargers (3)

What has to be taken into account while charging batteries?

A few practical tips:

  • Never charge primary batteries. They will become hot and can leak or even explode.
  • Rechargeable batteries must be fully charged the first time because they are supplied uncharged by the manufacturer. Recharging the batteries for the first time will always take longer than normal and should preferably be done in a slow way (don’t charge the batteries fast).
  • Don’t charge the batteries in a cool environment (below 0 °C). However, once recharged the batteries can be used excellent in an environment with low temperatures.
  • Make sure the batteries are fully charged for the first time. Don’t take them out of the charger halfway the charging process; this has a negative effect on the batteries. To prolong the life on a battery, it is also important to electronic discharge it prior to recharging the battery again. The first time, or after prolonged rest, it may happen that the battery is not fully charged and will not reach the desired capacity. In this situation, it is advised to fully discharge the battery and recharge it once again.
  • It is often desirable that NiMH batteries are fully charged within 1 to 2 hours. Given the composition of NiMH batteries, fast charging is not recommended within this amount of time. Chargers made specifically for these NiMH cells need at least 3 to 4 hours to fully recharge these batteries.
  • After the charging process, the charger should be able to switch to trickle charge. This ensures batteries stay fully charged when staying put for several days/weeks in the charger. The self-discharge is then offset by the extra energy the charger generates.
Which charger is best to use?

Unfortunately many unapproved and therefore cheap chargers are available on the market. These chargers recharge battaries only partially. A good charger complies with the following properties:

  • Fast charging: It is often desirable that NiCd batteries are fully charged within 1 to 2 hours. Given the composition of NiMH batteries, fast charging is not recommended within this amount of time. Chargers made specifically for these NiMH cells need at least 3 to 4 hours to fully recharge these batteries.
  • Automatic charging flow: It is important that chargers have a built-in checking system for the desired current of a particular battery type.
  • Protection against overcharging: Good chargers have an automatic built-in timer or electronic control system that prevents overcharging batteries when they are fully charged. Overcharged batteries become hot and thus the valve pops from the battery casing. In addition, overcharging batteries damages the internal system.
  • Trickle charging: After the charging process, the charger should be able to switch to trickle charge. This ensures batteries stay fully charged when staying put for several days/weeks in the charger. The self-discharge is then offset by the extra energy the charger generates.
What should I look at when charging?

A few practical tips:

  • Never charge primary batteries. They will become hot and can leak or even explode.
  • Rechargeable batteries must be fully charged the first time because they are supplied uncharged by the manufacturer. Recharging the batteries for the first time will always take longer than normally and should preferably be done in a slow way (don’t charge the batteries fast).
  • Don’t charge the batteries in a cool environment (below 0 °C). However, once recharged the batteries can be used excellent in an environment with low temperatures.
  • Make sure the batteries are fully charged for the first time. Don’t take them out of the charger halfway the charging process; this has a negative effect on the batteries. To prolong the life on a battery, it is also important to electronic discharge it prior to recharging the battery again. The first time, or after prolonged rest, it may happen that the battery is not fully charged and will not reach the desired capacity. In this situation, it is advised to fully discharge the battery and recharge it once again.
  • It is often desirable that NiMH batteries are fully charged within 1 to 2 hours. Given the composition of NiMH batteries, fast charging is not recommended within this amount of time. Chargers made specifically for these NiMH cells need at least 3 to 4 hours to fully recharge these batteries.
  • After the charging process, the charger should be able to switch to trickle charge. This ensures batteries stay fully charged when staying put for several days/weeks in the charger. The self-discharge is then offset by the extra energy the charger generates.

Environment (6)

Are batteries harmful to the environment?

From almost all batteries the harmful substances have been removed in the last few years. Only NiCd and lead acid batteries still contain heavy metals. Many of these batteries are already collected separately in accordance with all European directives. The battery industry is developing alternatives, in order to reduce the harmful effect of these batteries on the environment. NiMH, zinc air and lithium-ion batteries are examples of these developments.

Where is the removal contribution used for?

VIn the process from production to consumer a certain amount, called removal contribution, is charged for battery types and sizes. The Foundation Batteries (Stibat) has constructed an implementation plan for the collection and processing of waste batteries. Currently, approximately 80% of the batteries is collected spontaneously and were technically possible already recycled.

Where can batteries be deposited for recycling?

Individuals and businesses can return used batteries and battery packs to their municipality. In addition, many stores have so called battery-buckets in their store where consumers can deposit their used batteries.

What happens with the collected batteries?

Most returned batteries are being recycled. However, the mercury batteries that are available on the market form a major problem, because the current processing machines can only recycle 100% mercury-free batteries. Since the production and thus the sale of mercury batteries are stopped in the last few years, it is expected that this problem will solve itself soon.

What do the environment symbols on a battery pack stand for?

The official recycle symbol is a circle with three circular arrows. Batteries containing heavy metals are covered by the European Directive 157 and must be fitted with a special logo (a dustbin with a cross through it). These logos should induce costumers to return batteries instead of throwing them in the dustbin.

Do batteries require certain packing guidelines?

Yes. Directives stipulate that packaging should be reduced as much as possible and can be recycled.

Emergency lighting (11)

What does emergency lighting mean?

Emergency lighting, also called E-Light (= Emergency Light), ensure by means of a separate power source in the event of power failure, people are able to leave a building safely. On this page you can find the most important information regarding emergency lighting.

Emergency luminaries use rechargeable batteries, in most cases NiCd batteries. These batteries must have a higher capacity than the standard series and also be suitable to function in an environment with extremely high temperatures. Meanwhile, other techniques, such as NiMH, are emerging. However, these techniques are not (yet) applicable to situations where extreme temperatures occur. Emergency lighting is a safety device and therefore requires high demands on the reliability of the components and its batteries.

What regulation is of concern?

A number of laws and standards have been designed to guarantee safety:

NEN-EN 1838

NEN-EN 1838 defines the mandatory technical requirements which emergency lighting must meet within buildings. For example, a norm that requires emergency lighting to alleviate emergency exits for at least 1 hour and with at least 1 lux (autonomy) in the event of power failure.

NEN 1010

The NEN 1010 sets various requirements that must meet emergency lighting installations. For example, NEN 1010 sets requirements to escape route illumination (1 lux) and critical area lighting (10 lux). It also includes various techniques which have to be taken into account.

NEN-EN 1838 distinguishes three types of emergency lighting:

  • Escape route lighting: This lighting type ensures that escape routes are clearly identified and can be used safely. It includes lighting the escape routes themselves and their designation. The escape routes consist of the familiar icons.
  • Anti-panic lighting: This lighting type should ensure that people are led to a place where the escape route is recognized, with the aim to prevent panic.
  • Lighting of work places with increased risk: When power failure occurs at a workstation, it is intended that this emergency lighting is used to ensure work still can be done. For example, in case of dangerous situations it can be ensured that hazardous operations can be completed.
What is the NVFN and what does it stands for?

The Dutch Association of Manufacturers of Emergency Lighting (NVFN) is formed by the leading emergency lighting manufacturers on the Dutch market. Their main goal is to create clarity in both regulation and standardization of emergency lighting. On the website of NVFN a lot of information can be found regarding emergency lighting. The comprehensive FAQ section provides answers to diverse questions.

For further information go to: www.nvfn.nl.

When is emergency lighting applicable?

Emergency lighting can serve different purposes. Therefore, emergency lighting is not always enabled.

  • Only in case of emergency: In this situation the emergency luminair is turned off and will be activated in the event of power failure. The emergency lighting is powered by the battery of the lamp itself or through a central power supply box.
  • Switched lighting: In this case the illumination can be energized simultaneously with the normal lighting but can also be applied in night lighting. If the power fails, the armature will automatically be enabled even when it’s turned off. Power is provided via an internal battery or via a central power supply box.
  • Continuous lighting: In this situation the emergency light is always turned on. When power failure occurs, the armature will be powered by its own battery. When the main electricity supply is turned on, the lamp will be fed continuously.
What is of importance for maintenance and testing?

In order to insure emergency lighting works in critical situations, it is assured maintenance is of great importance. Furthermore, in many municipalities maintenance and inspections are required to get a valid permit. Battery checks should happen periodically (at least once every year) and it is recommended to replace an accumulator/battery every four years.

What does Elfa offer in the field of emergency power?

Elfa has the policy to implement only batteries with the NEN-requirements in its product range. These include, for example, batteries of the brand GP and Saft. In addition, Elfa offers numerous assembly possibilities that may fulfil the customers’ wishes in the field of E-light packs. Click here for an overview of the possibilities Elfa offers in this area.

In what sizes are the E-light packs available?

The batteries line used for emergency power has a limitation in number and sizes of cells. These sizes are:

Type cel Length/mm Diameter/mm mAh
sub-C cel 42,2 22,2 1200 and 1600
C cel 47,9 25,6 2200 and 2500
½ D cel 36,8 32,3 2500
D cel 60,3 32,4 4000 and 4500
How many cells does an E-light pack contain?
2 cells (2,4 V)
3 cells (3,6 V)
4 cells (4,8 V)
5 cells (6,0 V)
6 cells (7,2 V)
What does the configuration Stick and SBS mean?
  • Configuration stick: the cells are assembled on top of each other.
  • Configuration SBS (Side by Side): the cells are assembled next to each other.
What types of E-light packs are available?

E-light packs are available in Sub C, C and D cells:

  • With or without solder taps
  • With or without shrink sleeve
  • Faston tabs straight (4,8 mm)
  • Faston tabs Z (4,8 mm)
  • Faston tabs U 4,8 mm
  • Faston tabs + 4,8 / – 6,3 mm
  • Faston contra tabs + 6,3 / - 2,8 mm
  • Van Lien connector
  • Famostar connector
  • 30 cm cord

Also available: D cells: Only with a SBS configuration; with or without shrink sleeve.

What E-light battery brands are sold by Elfa?

Elfa sells E-light packs of the following brands:

  • Saft NiCd high temperature cells
  • GP NiCd high temperature cells
  • GP NiMH high temperature cells