1 .What is the difference between  Primary batteries and rechargeable batteries?

The battery's internal electro chemical determines whether the battery can be recharged or not. According to their composition and structure of the electrode electrochemical,we known the real internal structure of the rechargeable battery reaction is reversible reaction . In theory , this reversibility is not affected by cycles times , since the charge and discharge in the volume and structure of an electrode caused a reversible change, then an internal rechargeable battery must be designed to support this change. since , once the primary battery is only used for one time discharge , it is much simpler and does not require internal structure to support this change, so we can not use discharge battery to charge battery.If we charge, it will be very dangerous and not economic. If we need use repeatedly, it is better choice the one with 1000 times cycle life.This battery we called primary battery or rechargeable battery.

2 . What is a Li-ion battery?

Li-ion battery is evolved from battery. Therefore, before  introduced lithium battery first before introducing the Li-ion.For example , The button battery used in cameras before is belong to lithium battery . Lithium battery cathode materials are lithium metal and the negative electrode is carbon. When charging the battery , the lithium ions generated on the positive, the generated lithium ion moved through the electrolyte to the cathode . As the carbon negative electrode layered structure , it has many pores , the lithium ions reach the negative electrode embedded in the porous carbon layer , the more lithium-ion  embedded ,the higher of charge capacity  . Similarly, when the battery discharge ( ie, the process we use the battery ) , embedded in the carbon cathode layer lithium ion prolapse and moved back to positive . The more lithium ion back to the cathode , the higher of discharge capacity .Battery capacity we usually said  refers to the discharge capacity . In Li-ion charge and discharge process , lithium ions in the negative from the positive → → positive state of motion. Li-ion is like a rocking chair , rocking chair ends of the poles of the battery , while the lithium -ion as athlete running back and forth in a rocking chair . So Li-ion battery called a rocking chair.

3. Li-ion Battery components?

(1) battery top and bottom cover                

(2) the positive electrode - active material is lithium cobalt oxide   

(3) membrane - a special composite film     

(4) a negative electrode - active material is carbon

(5) an organic electrolyte solution               

(6) the battery case (divided into two kinds of steel and aluminum)

4 .How to achieve  Lithium ion security features?

To ensure safe and reliable Li-ion used , the experts were very strict and thorough safety performance battery designed to achieve battery safety assessment indicators.

1 ) diaphragm 135 ℃ automatic shutdown protection Adopt international advanced Celgars2300PE-PP-PE three-layer composite membranes. In the battery temperature reached 120 ℃ case , PE film on both sides of the composite membrane hole closed , the battery internal resistance increases , the internal battery temperature slow , battery temperature reached to 135 ℃ , PP membrane hole closed , the internal battery circuit, the battery is no longer warming, to ensure safe and reliable battery .

2 ) adding additives to the electrolyte Overcharge the battery  is in condition of the battery voltage  above 4.2V , electrolyte additives other substances in the electrolyte polymer , a substantial increase in the battery internal resistance , a large area inside the battery circuit, the battery is no longer heated .

3 ) Battery cover composite structure

The battery cover is made of Scotch explosion sphere structure , the battery temperature , the battery internal activation part of the gas generated in the expansion of the battery internal pressure increased, the pressure reaches a certain degree of rupture of the score , deflated.

4 ) a variety of environmental abuse testing Conduct various experiments abuse , such as external short circuit , overcharge , acupuncture, shock, burning ,etc., inspect the battery safety performance. While the battery temperature shock and vibration test , drop, shock and other mechanical properties test , inspect the battery in the actual use of the environment performance situation

5. What Charging voltage limit? Rated capacity? Rated voltage? Termination voltage?

A, Charging voltage limit

Required by the manufacturer, charging voltage value is the voltage when the battery charge transferred by the constant current to constant voltage

B, rated capacity

Manufacturers indicate battery capacity refers to the battery in an ambient temperature of 20 ℃ ± 5 ℃ conditions, the rate of discharge to the 5h end voltage of electricity to be provided, with the C5 expressed in units of Ah (ampere hours) or mAh (milli An hour)

C, nominal voltage

To indicate the approximate battery voltage.

D, the termination voltage

Provides the load of the battery discharge termination voltage, the discharge limit value n * Nominal V (lithium ion only a few single cells in series with the "n" indicates).

6.Why constant charging current is gradually reduced?

Because of when the constant current process terminates, the electrochemical polarization should remain within the cells of the same level, in the constant current, constant pressure process under the action of a constant electric field, internal Li + concentration polarization in gradually eliminate, ion transference number and speed of current gradually decreases.

7. What is the capacity of the battery?

The capacity of the battery can be divided into rated capacity and the actual capacity. Battery rated capacity refers to the design and manufacture of battery requirements or to ensure the battery discharge under certain conditions, it should emit a minimum of power. Li-ion battery at room temperature specified, constant current (1C) under constant voltage control charging rechargeable 3h, the actual capacity of the battery is discharging the battery under certain conditions, the release of the actual consumption, mainly due to the discharge rate and temperature (strictly speaking, therefore, the battery charge and discharge capacity should indicate the conditions).  The Common capacity units: mAh, Ah = 1000mAh

8. What is the battery internal resistance?

It Refers to the current flowing through the resistance of the internal battery when the battery at working.the  resistance made up from  Ohmic  and polarization resistance. Battery internal resistance is big , may lead to lower voltage battery discharge, the discharge time shortened. Mainly by the size of the battery internal resistance of the material, manufacturing process, the cell structure and other factors. Is a measure of battery performance is an important parameter. Note: generally charge state resistance as the standard. Measure battery internal resistance equired special resistance measured, rather than using a multimeter ohm measurements.

9 . What is the open-circuit voltage?

Refers to the battery in a non-working state of the circuit means  that no current flows between the battery positive and negative electrical potential difference . Open circuit voltage of the battery , you can determine the battery state of charge .

10. What is the working  voltage?

Also known as the terminal voltage , the battery is in working condition that the circuit has a current outdated battery potential difference between positive and negative . Discharging operation of the battery state, when the current flowing through the battery inside , without overcoming the resistance caused by the internal resistance of the battery , the battery open circuit voltage is always lower than the open-circuit cell However charge time is the opposite.

11 . What is a discharge platform?

Discharge platform is maximum charging voltage charge to the nominal voltage and the electric current is stopped when the charge is less than 0.01C , and then set aside for 10 minutes, at any rate of discharge current to the nominal voltage of the discharge the discharge time， it  Is a important measure of battery is good or bad.

12 . What is ( charging and discharging ) magnification ? Time rate?

Refers to the battery required current value when release its rated capacity Within the stipulated time, which is  equal to the data value multiple of the rated capacity , usually expressed with the letter C .

13 .what is problem will be appeared when the combined use of different capacity?

If  the different capacity or  old and new batteries  are mixed to used , there may be appear leakage, zero voltage and so on. This is due to the charging process , the capacity differences lead to some of the battery is overcharge, some of the battery is not fully charged ,when  the discharge some high capacity not  is not fully discharged , while the capacity of the low were over-discharge . a vicious cycle , battery leakage or damage and low ( zero ) voltage.