Battery for Hubsan H122D not charged

[Pick_cz]

Hello,
I got a pack of batteries from here: https://www.banggood.com/Hubsan-H122D-RC-Quadcopter-Spare-Parts-7_6V-710mAh-Li-Po-Battery-H122D-16-p-1257546.html
charged them with the original charger (until the light is solid red) and the voltage on all of them drops from 8.1V to 6.6V in seconds (readings from the LCD monitor). Sometimes the drone even shut itself off on take off. Thats the behaviour of those 4 new batteries in their first attempted flight.

What is happening? What can be done?

Thanks,
Pick

[vivianfranco]

Hello Pick,

Thank you for contacting us. Please contact the seller. By Hubsan Policy they don't cover lipo batteries under warranty.

[Pick_cz]

Hi,
Alright, I was curious if you have some tips and tricks how to revive those batteries. The seller refunded me and I bought a few more from other place. I hope they will work fine.

Fly safe,
Pick

[Alex007]

It may be the fault of the charger. I no longer use the stock charger as I found it did not give a balance charge, See if you can get hold of a BC 4S15D charger that gives a proper balance charge through the balance plug.

OK. It is not a HV charger and will cut off at 4.2V per cell but that makes only a very slight difference to the flight time.