1. Constant current and voltage limit, charge the battery with a certain current and switch to low current charging after reaching the set voltage.
2. Constant voltage and current limitation, use a certain voltage to charge the battery, detect that the current drops to a certain level, and convert it to a smaller voltage for low current charging, such as a battery. Car charger.
3. ΔV/Δt detection, that is, the battery voltage slope detection is complete, such as Maxim's MAX712/713 charging circuit.
4. There are still inferior chargers on the market that use current-limiting time charging, which does not detect whether it is full or not, but only synchronizes.
Battery power percentage is displayed on mobile phones, tablets and computers. It is fully charged whens it reaches 100%. For other devices that do not display power, charge them according to the battery capacity or instructions. . Ordinary electronic devices usually take a few hours to be fully charged, and the lithium battery can be charged at any time. There is no need to fully charge it every time.