The end-of-charge voltage is a characteristic value of rechargeable batteries. It is the voltage that is applied to the battery terminals as terminal voltage during the charging process with the charger connected.
The end-of-charge voltage is higher than the nominal voltage. For NiCd batteries, for example, the nominal voltage is 1.25 V, the final charge voltage is 1.4 V per battery cell, and the final discharge voltage is between 0.8 V and 0.9 V. For lead-acid batteries, the final charge voltage is about 2.4 V per battery cell, the nominal voltage is 2.0 V and the final discharge voltage is 1.75 V, and for Lthium-ion batteries, the final charge voltage is 4.2 V and the final discharge voltage is 2.5 V.
When the charging end voltage is reached, the IU charging process is switched from constant current to constant voltage. The charging end voltage can be set on the chargers and is reached earlier as the nominal capacity falls.