Battery FAQ

1. What is a battery?»»Battery is the device that transforms the chemical energy to electrical energy through the chemical reaction between the anode and cathode.

2. What is the primary battery and secondary battery?

»»The primary battery refers to the battery that can only discharge and is not rechargeable. The secondary battery refers to the rechargeable battery that can be charged and used in duty-circle operation.

3. What are the main components of battery?

»»The main components are: the positive plate, the negative plate, diaphragm paper, cap, can, and insulating layer.

4. What is the cycle life of rechargeable battery?

»»When a battery experiences a charge and discharge, we call a cycle or a period. In the stated charge and discharge principles and the capacity decline before a stated standard, the total cycles it can undergo called rechargeable battery cycle life.

5. What is battery inner impedance?

»»Battery impedance is the resistance when the current flow through an operating cell, in general the internal resistance is included both d.c. and a.c. resistance. For the rechargeable cell resistance is small and electrode is easy to be polarized along with producing a polarization resistance while measure d.c. resistance, the accurate value can’t be measured.

6. What is the memory effect?

»»Memory effect only happens on Ni-CD batteries. As in traditional technology a Ni-CD battery’s negative is agglomeration with thick Ni crystal, if Ni-CD batteries are recharged before they have been fully discharged, Ni crystal easily gathers to form agglomeration, which makes the primary discharge platform come into being. The battery stores the platform, which will be considered as the end of discharge for the next cycle even though the capacity decides that the battery can be discharged to a lower platform. The battery will store this process in its memory so during the next discharge, the battery only remembers this reduced capacity. Similarly any further incomplete discharge in each use will aggravate the effect makes lower capacity. The effect there are two methods to remove the effect: firstly deep discharge at trickle current (i.e. 0.1C to 0V), secondly several cycles at high currents (e.g. 1C).

7. What is “short circuit”? May I short circuit Lithium battery?

»»If the positive and negative terminals come into contact with each other or with a metal object, this can cause a short circuit, generating heat. If the batteries are stacked on top of each other or Mixed, the resulting short circuit can lead to heat generation, leakage, bursting and eventually fire. Do not short circuit Lithium batteries.

8. May I apply heat on Lithium batteries or dispose of in fire?

»»If heated to 100°C or more, plastic materials in the battery such as the gasket and separator may be damaged, causing leakage. The heat generated by a short circuit inside the batteries may lead to bursting or combustion. If disposed of in fire, batteries may burn violently.

9. May I solder Lithium batteries directly?

»»If solder is applied directly to the battery, resin materials in the Lithium batteries such as the gasket and separator may be damaged due to overheating. This can cause leakage, and heat generated by a short circuit inside the battery may lead to bursting or fire. Even if no abnormality takes place immediately after soldering, the resulting leakage and other damage may harm the components attached to the battery over a long period of usage.

10. May I charge Primary Lithium batteries?

»»When a Primary Lithium battery is charged, gas is generated inside the battery and can result in swelling, heat generation, leakage bursting and fire.

11. May I force discharge Lithium batteries?

»»When batteries are force-discharged with an external power source, the voltage drops to under O V (reverse electrode), and inner gas is generated. This can lead to swelling, heating, leakage, bursting or fire.

12. May I disassemble, apply excessive pressure on Lithium batteries?

»»If a battery is disassembled by force, gas may be generated which may cause throat irritation, or the Lithium metal may generate heat, causing fire. If deformed under pressure or under impact, distortion of the seal may lead to leakage, or a short circuit inside the battery may lead to swelling, heat generation, bursting or fire.

13. Can I use Lithium batteries mixing with other battery types?

»»If different types of batteries are used together, or new batteries are used with old ones, the difference in characteristics of voltage, capacity, etc. , may cause over-discharge of the battery which is exhausted first, leading to swelling, bursting or fire.

14. Can Lithium battery be contacted with water?

»»No. This may cause corrosion or the formation of combustible gas.

15. Can the battery be kept inside the appliance if the battery is used up or in long-term nonuse?

»»The battery had better be taken out from the appliance and kept in a dry place with low temperature if the appliance is in long-term nonuse. If not so, the system will still make the battery discharge a low current. It will reduce the service life of the battery.

16. Where Lithium batteries should be stored?

»»Lithium batteries should be stored in a place not exposed to direct sunlight. Make sure the area is dry and has minimal temperature variation. Storage in areas subject to high temperatures, humidity or rain may cause deterioration in battery quality and durability. To avoid short circuiting batteries during storage, be sure that the positive and negative terminals do not come in to contact with each other.

17. What is passivation for Li-SoCL2 battery? How to avoid the problem caused by passivation?

»»Passivation is a chemical term and it refers to phenomena that a kind of chemical film appears on the surface of the metal and prevents the further corrupt from happening on the surface of the metal. In lithium thionyl chloride battery, thionyl chloride is liquid. Metal lithium gets in touch with thionyl chloride completely and will slowly rust just like iron. The production of this rust is lithium chloride. The lithium chloride produced on the surface of the metal lithium in thionyl chloride is very compact and prevents the reaction of lithium and thionyl chloride. This phenomenon is passivation. The passivation of lithium thionyl chloride battery happens as soon as the battery is produced, but this reaction is not fast in speed. Just like all the chemical reaction, the speed of passivation is related to the temperature. The higher the temperature is, the faster the speed is. The longer the time is, the more serious the passivation is. Please contact EEMB sales global@eemb.com for advice about how to avoid the problem caused by passivation.

18. What effect can the battery bring to the environment?

»»Now nearly all the battery do not contain mercury, but heavy metal is the important component for mercury battery, rechargeable nickel cadmium battery, lead acid battery. If there is improper handling, these heavy metal will have bad effect on the environment. Now, internationally there are special institutes that recall the nickel cadmium battery and lead acid battery. Our company has been devoting to replace the nickel cadmium battery with nickel metal hydride battery and lithium ion battery.

19. What effect can the temperature bring to the battery performance?

»»Among all the environmental elements, temperature has biggest effect on the battery performance. The electrochemical reaction on electrode / electrolyte interface is connected with the temperature. The electrode / electrolyte interface is considered to the heart of the battery. If the temperature gets lower, the reaction rate of the electrode also gets lower. If the battery voltage keeps invariable, the discharge current becomes lower, and also the power output will reduce. If the temperature goes up, the condition is reverse. That is, the battery’s power output will increase. Temperature will also affect the speed of the transmission of the electrolyte. If the temperature goes up, the speed of transmission will be faster. If the temperature goes down, the speed of transmission will be slower. The battery performance will also be affected. But if the temperature become too higher, the chemical balance inside the battery will be broken and side reaction will be caused.

20. What are the possible reasons for the battery service life reduction?

»»Charger or charging circuit is not matching to the battery type. »»Over charge and over discharge. »»Battery type is not matching to the appliance.

21. What are the possible reasons for zero voltage or low voltage of the battery pack?

»»Single battery in the battery pack is zero voltage. »»Short circuit or open circuit of the connector or wrong connection. »»Desoldering or cold solder joint between the batteries and lead. »»Wrong connection between the batteries. There is desoldering or cold solder joint between the connection strap and battery. »»The wrong connection or failure of the electronic components inside the battery pack.

22. What are the possible reasons for zero voltage and low voltage of the battery?

»»The outside short-circuit on the battery, overcharge, or over discharge. »»The battery is continuously over charged by the very high current. »»The battery is internally short-circuited or slight short-circuited.

23. What are the possible reasons if the rechargeable battery or rechargeable battery pack can not be charged?

»»The battery is zero voltage or there is battery with zero voltage in the battery pack. »»There is wrong connection inside the battery pack. »»There is abnormity of electronic components and/or PCB inside the battery pack. »»Failure in charger. »»Outer element causes the charging efficiency to be too low, such as extremely low or high temperature.

24. What will happen if the batteries with different capacity are packed together?

»»If the batteries with different capacity or new and old batteries are used together, leakage, zero voltage and so on might happen. If the battery are rechargeable and are being charged, some batteries is overcharged and other batteries is not in full charged state. During the discharge, some batteries can not discharge fully and other batteries might over discharge. This way, the battery will be damaged.