Battery Discharge Plateau

Battery discharge platform indicates the stable discharge time of rechargeable battery. For Ni-MH battery and Lithium Battery, discharge plateau requirements are different.

For nickel metal hydride battery, Battery Voltage does not falls with a same slope during discharge after battery is fully charged. Generally, at the beginning of discharge, voltage drops quickly; after a period, battery voltage hardly changes or has little change. This discharge period, which takes up the vast majority of whole discharge time, is discharge voltage plateau. After battery almost finishes discharging, voltage goes down quickly until cutoff voltage.

Briefly speaking, when battery discharges under constant current, voltage experiences down, stable and down process, among which, stable stage is discharge plateau.

As far as lithium battery, discharge platform means capacity or discharge time from full charged voltage to rated voltage under specified discharge condition (for instance, discharge rate, temperature, etc). Longer discharge time or higher discharge capacity proclaims higher battery discharge platform.

Discharge platform of lithium battery is discharge time from 4.2V through CV charge to 3.6V under any discharge rate current. It is an important criterion to measure battery performance.

Discharge platform curve is smooth and has a long duration time at a certain voltage. For different discharge rate, discharge platform is different. Many factors should be considered during choosing discharge platform because sometimes higher discharge platform implies low capacity.

Only high capacity, long duration time under a certain voltage and higher platform voltage proves whether battery is good or not.