Those who say you need to charge for 12 hours are the ones who don't understand lithium battery chargers at all and follow what others say.
The lithium battery charging process is divided into two stages. The first stage is constant current charging until the set voltage is reached. After entering the second stage of constant voltage charging, the current gradually decreases as charging progresses. When the set cut-off current is reached, the charging process is completely finished. Unlike NiMH batteries, there is no longer any maintenance recharge, there is a total power cut.
The whole process usually takes 2 to 3 hours.
Leaving the battery in the charger for ten hours after charging is an annoying thing for ignorant people.