What is the characteristic of a portable battery?
Every battery constitutes an energy converter. It is capable of converting stored chemical energy into electricity energy directly. In the case of rechargeable batteries, this process is described as the following: when charging electricity energy is converted into chemical energy ->during discharge the conversion is reversed->during charge electricity energy is converted into chemical energy, on secondary batteries this process can repeat more than 1000 times.
Rechargeable portable batteries are available in different electrochemistry battery systems, i.e. lead acid systems (2V), Ni-Cd systems (1.2V), Ni-MH systems (1.2V), and Li-ion systems (3.6V). The typical characteristics for the above battery systems are their relatively constant discharge voltages (when discharge a voltage flat roof is available), as well as the quickly breaking down voltages both at the beginning and the end.

What are the advantages and disadvantages of rechargeable battery?
Long service life is the advantage of the rechargeable battery, for it can be recharged for more than 1000 times. It is economical for frequent use even though it is more expensive than primary batteries, and its load capacity is more powerful than most of primary batteries. Generally a Ni-MH battery is not recommended to use in cameras because its discharge voltage is almost constant and it is difficult to predict when the discharge ends, while rechargeable Li-ion batteries can provide camera longer service time, higher load, higher energy density, voltage decrease in discharge with discharge deeply going.

What kind of applications are rechargeable batteries preferred?
Rechargeable batteries are particularly applicable well to devices which require comparatively higher power supply or strong current discharging such as portable cassette players, CD displayer, mini radios, electronic game players, radio control toys, various household applications, professional cameras, mobile telephones, cordless phones, notebook computers, and other higher power requirement devices. Rarely used equipments are not recommended to use rechargeable batteries for its comparatively higher self-discharge. But if a device requires discharging at stronger currents, rechargeable batteries are necessary. In general it is wise to follow the appliance manufacture's guidelines for battery selection as given in the operating instructions.

Which types of rechargeble batteries are available? For which applications are they especially suit?
Battery types Characteristics Applications
NI-MH round cell Environmentally benign (contain no mercury, lead, cadmium)Overcharge-proof Audio devices, camcorders, mobile phone, cordless phone, emergency light, notebooks computers
Ni-MH prismatic cell High capacity, environmentally benign, overcharge-proof Audio devices, camcorders, mobile phone, cordless phone, emergency light, notebooks computers
Ni-MH button cell High capacity, environmentally benign, overcharge-proof Mobile phone, cordless phone
Ni-Cd round cell High load capacity Audio devices, power tools
Ni-Cd button cell High load capacity Cordless phone, EMS memory
Li-ion cell High load capacity¡¢high energy density Mobile phone, notebooks, video cassette recorder

What is the service life of rechargeable battery on cordless phone?
Under normal conditions, its service life is 2-3 year or longer. If any one of the following items occurs, the batteries should be replaced:
1) After each charge, the talk time becomes shorter;
2) Ring sign is not enough clear or talk effect is indistinct and chirp voice is louder.
3) The distance between cordless phone and the base should be closer and closer, i.e. the ranges that the phone can work become narrower.

What types of batteries are used for watches?
There is a wide range of button cells available for watches. The preferred electrochemical system is silver oxide. The type of battery to be used is listed in the watch's operating instructions. In general, analog watches (hands watches) and simple digital watches all can be powered by low drain batteries.

What other battery systems can be used for watches?
In addition to the silver-oxide system, alkaline-manganese and lithium-manganese systems are also used in watches. The alkaline-manganese button cell is most commonly used for low price watches. An identical sized silver-oxide button cell can later replace this battery. The advantage of the silver-oxide button cell is its constant operating (highly accurate time-keeping) and higher capacity (longer operation). Another category of watches uses lithium coin cells (further information), which may also be equipped with multiple functions. A typical coin cell for this purpose is the CR2025, with a diameter of 22mm and a height of 2.5mm. In total there are more than 12 different sizes (different diameter and height).

What is the self-discharge rate of the solar battery?
Compared with the other rechargeable battery systems, solar batteries with liquid electrolyte have obviously lower self-discharge of 10%/month at 25¡æ.

What is an intelligent secondary cell?
Intelligent batteries are equipped with an electronic chip which not only supply energy to the devices, but also control its main function. This kind of batteries can show the rest of its capacity, having been cycled times, temperatures and so on. Yet currently it has not been available on market, in future they will play a major role-especially being used in portable videos, cordless telephones, mobile phones and notebooks.

Can primary cell be recharged?
An alkaline-manganese round cell can be recharged about 20 times. In reality, however, this is not a true recharge process as offered by secondary batteries, because they do not permit a normal deep discharge like a true rechargeable battery, but only a partial discharge. Consequently, the recharge process is also only a partial one, and which therefore should be better called "regeneration" to differentiate it from a true recharge as offered by secondary batteries. The serious limitation of its charge/discharge behavior and its very short "cycle life" renders the regeneration of an alkaline-manganese battery rather uneconomical.
Various conditions must be met in order to ensure the successful regeneration of alkaline-manganese batteries:
1)A regeneration is possible only if a maximum 30% of the battery's initial capacity is withdrawn at moderate discharge rates, whereby the discharging voltage should not drop below0.8V. When removing more than 30% of the capacity, an irreversible manganese dioxide structure will develop that prevents any further "regeneration". The 30% "capacity point" and the 0.8V discharge voltage can only be monitored by use of proper measuring instruments, which the average consumer does not possess.
2) Alternatively, the user would need to buy a charger for performing regeneration. Other charging devices like charges for rechargeable nickel-metal-hydride or nickel-cadmium accumulators should never be used. Because their charging current may be too high and may lead to gas generation inside the battery, which in turn may lead to the safety vent opening and electrolyte being ejected. In extreme cases an explosion may even occur if the safety vent fails to respond (due to e.g. a molding defect during production). Cases like this happen very rarely, nevertheless they can happen, especially if the battery is not used properly.
3) The length of time needed for "regeneration" (approx. 12 hours) is out of all proportion to the discharge time (approx. 1hour).
4) After about 20 partial cycles at the very latest, the battery capacities will nave dropped to about 50% of its initial value.
5) If a given device needs more that three batteries connected in serious, an additional problem will arise if the batteries have differing capacities as a result of "regeneration". This can lead to a voltage reversal of the weakest battery. This danger is particularly likely if regenerated batteries are used together with fresh ones. A battery reversal leads to hydrogen evolution inside the battery, with the danger that unacceptably high pressures will build up. This can result in electrolyte being ejected and even an explosion!
Regeneration of primary batteries is not only uneconomical in the long run, but bears in itself a safety risk. To avoid these risks it is better to use fresh primary batteries or secondary batteries (accumulators) rather than to regenerate primary ones.

Can 1.2V rechargeable batteries replace 1.5V alkaline manganese batteries?
The alkaline manganese battery discharges over the voltage range 1.5V and 0.9V,whereas rechargeable portable batteries discharge at a virtually constant voltage of 0.2V/cell. This voltage level is roughly equivalent to that of the average discharging voltage of an alkaline manganese battery. Therefore, exchanging a rechargeable, portable battery for an alkaline-manganese battery or vice versa should never be a problem.

Why are lithium batteries particularly suited for cameras?
Lithium batteries offer relatively high volume-specific energy (approx.800mWh/cm³). In addition, lithium batteries, which have spirally wound large-surface electrodes, have a high load capability and high capacity retention during storage. Both the lithium battery's longer operating time and its higher cell voltage of 3V are important in camera applications, The latest generation of cameras is fitted out with numerous automatic functions, which means increased energy coupled with relatively high load requirements. Lithium batteries of this type are a particularly good choice for today's cameras.

When is it preferable to use a high-capacity accumulator for a mobilephone?
High-capacity accumulators deliver a longer operating time than slimline accumulator; however, they are heavier and larger. Slimline accumulators are lighter and are especially designed to fit mobile telephones, but offer a shorter operating time. This aspect should be kept in mind when selecting an accumulator for a mobile telephone.

What are the advantages of a solar battery?
Solar energy systems are easy to install, easy to expand, and easy to disassemble. They are economical as well, since there are no energy costs during operation. In addition, solar energy systems are subject to virtually no mechanical wear. A solar energy system requires a reliable solar battery for charge acceptance and storage. General solar batteries are characterized by:
1) High charge acceptance
2) Durability in cycle operation
3) Good rechargeability
4) Maintenance free

Which batteries will dominate the market in years to come?
In years to come, rechargeable portable batteries will probably have a large market share than primary batteries. The popularization of portable camcorders, mobile and cordless telephones, notebooks and multimedia devices more and more rechargeable batteries are need

Will there be a system in future that will combine all the characteristics?
Presently all kinds of batteries will still exist for a long time. Because each one of today's battery systems is a specialist in its own right, able to fulfill a specific task better than any other battery system. They all specialists either in terms of value for money, high capacity, high energy density, long shelf life, high or low operating temperatures, environmental compatibility or economical, environmentally benign recyclability. A battery system capable of combining all such characteristics is unlikely ever to be available.

What are the advantages of Li-polymer battery?
1) No liquid electrolyte, so never leak;
2) Can be made into various shape;
3) Can be made into thin battery, such as 3.6V, 400mAh, the thickness can decrease to 0.5mm;
4) Battery is transmutable and can be crooked: the maximum angle is 900;
5) High voltage in an battery: several battery with liquid electrolyte can be connected in series to get a high voltage only; the Li-polymer battery can get high voltage in an cell through multiplayer combination;
6) Same volume Li-polymer batteries' capacity is two times of Li-ion battery.

What are the advantages of Ni-Cd battery?
1) Low cost;
2) Excellent overcharge endurance;
3) Excellent quick charge performance;
4) Long cycle life;
5) Extensive temperature range;
6) Mid-degree self-discharge;
7) Good safety performance.

What are the advantages of Ni-MH battery?
1) Low cost;
2) Good quick charge performance;
3) Long cycle life;
4) No memory accumulation;
5) Green energy sources, no pollution;
6) Extensive temperature range;
7) Good safety performance.

What are the advantages of Li-ion battery?
1) High energy density;
2) High operation voltage;
3) No memory accumulation;
4) Long cycle life;
5) No pollution;
6) Light weight;
7) Very low self-discharge rate.

What is nanometer battery?
Nanometer means 10-9m. Nanometer battery is made with nanometer materials(such as nano-MnO₂, nano-LiMn₂O₄, nano-Ni(OH)₂). Nanometer materials have especial microcosmic structure and physical & chemical performance (such as quanta size domino offect, surface domino offect and tunnel quanta domino offect). Up to now, the nanometer battery with mature technology is nanometer activated carbon fibre battery. It is used in electric automobile, electric motor and electromotion-aid vehicle. This kind battery can be charged and discharged about 1000 cycles, use duration is about 10 years. Fully charge a battery only spends about 20 minutes, the journey in flat road is about 400km, and its weight is 128kg. It has exceeded the technology level of American and Japan: their Ni-MH battery needs 6-8h to be fully charged, andthe journey in flat road is about 300km.

Which types battery are used in emergency lighting?
1) Seal Nickel-Cadmium battery
2) Lead-acid battery with adjustable vent
3) Other battery which is in accordance with corresponding safety and performance requirements of IEC standard (emergency lighting part) can be used too.

Which type battery can be used in remote control devices?
The battery stipulated in its battery compartment should only operate a remote control device. Different zinc-carbon batteries are available for different remote control devices. They can be identified by their IEC designation. Commonly used batteries include the R03 (AAA, "Micro"), R6 (AA, "Mignon") and the 9V Block 6F22. A better choice is the alkaline versions of these batteries which offer twice the operating time of the zinc-carbon battery. They can be identified by their IEC designations LR03, LR6 and 6LR61. Nevertheless, because of the relatively low current required by this application, zinc-carbon batteries still remain a good and economical alternative.
Interchangeable accumulators may - in principle - be used as well. They are, however, less recommendable for this application because of their relatively high self-discharge, which requires repeated charging, thus rendering this type of battery rather impractical.

What are "dry" and what are "liquid" batteries?
The terms "dry battery" and "liquid battery" are restricted to primary systems and date from the early development of galvanic elements. At that time, a liquid cell consisted of an electrolyte-filled glass container into which electrochemically active electrodes were immersed. It was only later that unspillable cells which could be used in any position and had a completely different construction were introduced, these being similar to today's primary batteries. These earlier cells were based on paste electrolytes. At that time they were known as dry batteries. In this sense today's primary batteries are also dry batteries.
The term "liquid battery" is in principle still applicable to certain modern secondary batteries. For large stationary lead-acid or solar batteries, liquid sulfuric acid is preferred for the electrolyte. For mobile applications unspillable, maintenance-free lead-acid batteries are recommended and have been available for many years. Their sulfuric acid is immobilized by a gel (or a special microglass mat).

What are "portable batteries"?
A portable battery is primarily a battery which provides electrical energy to operate portable, cordless equipment. In a more generalized definition it also includes batteries that only operate certain sub-devices within a larger system (which may be operated by the mains), e.g. a desktop computer. Sub-devices of the above kind may be a computer's internal clock or a memory backup. Larger batteries (e.g. four kilograms and above) are no longer considered portable. Today's typical portable batteries will weigh several 100 grams.
The portable battery family includes both primary and rechargeable (secondary) batteries. Button cells belong to a special group of their own.

Do alkaline-manganese batteries really last longer than zinc-carbon?
Yes, they do. The alkaline-manganese battery has nearly twice the energy content of a zinc-carbon battery of the same size, even at higher loads. This battery is particularly suited for continuous discharge. For low power applications (such as transistor radios) or applications using discontinuous discharge regimes (e.g. flashlights), the zinc-carbon battery still represents an interesting and inexpensive alternative. The on-load period should preferably not exceed five minutes at higher loads. This limitation does not apply for the more expensive alkaline-manganese batteries.

May any charger be used to recharge portable batteries?
No, because each charger employs a specific charging technology which is matched to a given electrochemical system, e.g. lithium-ion, lead-acid or nickel-metal-hydride. They differ not only in their voltage characteristics, but also in their charging mode, e.g. only quick chargers which have been specially developed for nickel-metal-hydride batteries will ensure optimal charging results for this system. Former Varta chargers for nickel-metal-hydride batteries can continue to be used, but may need more time to fully charge the battery. Care must be taken when using a charger that does not meet the required charging conditions for a given electrochemical system, even if it carries a label that seems to signal "officially approved". A label of this kind may only state that the device was wired according to the European Electrochemical Standard (CENELEC) or other national standards such as VDE (in Germany: Association of German Electrotechnical Engineers)! This type of label does not make any reference to the charger's suitability for a specific battery system. With cheap devices of this kind, charging nickel-metal-hydride batteries can be both dangerous and lead to unsatisfactory results. This warning also applies to chargers developed for other systems (e.g. lead-acid accumulators)

What is a micro battery/button cell?
A "button cell" should actually be better called a "button battery", because it has the external attributes of a battery (further information) . Its popular name, however, is "button cell". A button cell may be defined as a battery whose diameter is equal to or larger than its height. Present dimensional limits for button cells using an aqueous electrolyte range from a) diameter: 4.8 mm to 11.4 mm, b) height: 1.05 mm to 5.4 mm. Depending on the electrochemical system their nominal voltage is either 1.2V, 1.35V, 1.4V, 1.5V or 1.55V. Batteries of this family were given this name because of their visual similarity to buttons. Coin Cells also belong to the group of button cells (further information).