[Gray]

Friends I bought a 4s 850mah lipo battery my question is how many minutes do you need to charge this battery. If left plugged in for too long, the battery will lose its function.
It needs to be removed for use shortly before the battery is fully discharged. That is, there is a short amount of time left until it is used. Until... Is such a thing true?
I'm waiting for answers from friends who have this knowledge.

[TheOtherCliff]

You must use a Lipo charger to charge a Lipo.

Lipos are generally charged at 1C and so all Lipos take an hour to charge.  Example: an 850 mah lipo is charged at 850ma so it takes 1 hour.  This varies a bit because the battery may be partially charged and doesn't need so long.  Also, the Lipo charger knows to charge slower as the battery gets full.  Also, the Lipo charger knows when to stop charging.

To get the Lipo to last a large number of charge cycles, you need to:
- charge it at 1C
- always store the battery in a cool place at storage voltage (3.8v per cell).
- never over discharge (less than 3.3v per cell, better yet never less than 3.6v per cell)
- do not drain the battery faster than it is designed for (C rating).  better yet, only use 1/2 C rating.