How Long Used for P4 Battery

[muriel]

After the end of flight P4, if you forget to turn off the battery switch, the consequences will happen?
I need to buy two more batteries.

 

[John Locke]

If you accidentally leave a battery on, the battery should auto shut off at 3.0V to protect it from damage. It should recharge fine. Are you saying you have two batteries that won't charge? If that's the case you should return them to DJI under warranty.