Q1.) Discharge Ans.) Electrons flow from anode through the external load to the cathode. To complete the circuit ions pass through the electrolyte between anode and cathode. Q2.) Charge Ans) The recharge process reverses the flow of electrons and the anode and cathode roles. Whereas the terminal which under discharge was oxidized, it is now reduced, and the terminal which under discharge was reduced is now oxidized. The circuit is completed by transfer of ions through the electrolyte. In a primary battery once discharged, the process cannot be reversed and it is discarded, in a secondary battery or storage battery a recharge process can be used to renew the unit Q3.) Electrochemical principals and reactions:/ performance Ans.) Several factors affect the conversion efficiency of a cell. The activation polarization, the concentration polarization, and internal impedance or IR loss¡¤. The total internal impedance of a cell is the sum of the ionic resistance of the electrolyte and the resistances of current carrying components. When operated at low current discharge rates, the polarization and IR losses are at minimum, thus the output voltage is near the open circuit no load voltage and can deliver most of its available energy. With higher currents, the IR losses increase, lowering the output voltage at the terminals and the discharge slope is a steeper decline. A common way to specify the charge and discharge current of a battery is the C rate. It denotes the rate of total battery capacity. It is calculated by dividing the charge or discharge current by the total numerical battery capacity ¡£Ampere-hours, Ah¡¤. For example a 30Ah battery is discharged with a current of 6A. The C rate is equal to 6A / 30Ahr=0.2C rate, also expressed fractionally as a C/5 rate. Need help deciding?     Conatct us >> Q4.)Temperature effects Ans.) A battery life will be less at lower temperatures. As the temperature is lowered the electro-chemical activity lessens and the internal resistance increases. This does not mean that the higher the temperature, the longer life is achieved. Depending upon the type of battery, too high a temperature will cause chemical deterioration and loss of capacity. The main thing to remember is to keep batteries cool during storage and warm ¡£never hot¡¤ during operation. Consult the manufacturers specifications for recommendations and limits. Q5.) Battery age and storage Ans.) Things that influence the life of a battery include the cell design, the electro-chemical process, temperature, and time. During storage, some battery types develop protective films or coatings on the active material. Once placed into service, these cells may experience what is called "voltage delay", a lower voltage output temporarily until the film is broken through by the electro-chemical reaction. The films can greatly extend the shelf life of the cell. Q6.) Battery capacity Ans.) The capacity of a battery is expressed in units of electric charge, coulombs or ampere-hours. Q7.)What the maximum discharge current of Li-ion battery? Ans.) About 2C for continuous discharge and 3C for instantaneous discharge. But these numbers can be changed by re-designing the battery. For example, by sacrificing about 25% capacity we can increase the maximum discharge rate to 6C. Questions or Suggestions ? Contact us