Eflite umx pitts battery charger

by Brian Heap
(Luna, NM, USA)

I have this great flying plane, but now when I plug the charger to the battery, the charger blinks red and green all the time. This means it's balancing.

After hours of this it never charges. I ordered a new charger and it does the same thing. The batteries were so low they only moved the servos, motor didn't turn.

Put T pins in the battery plug and charged a little of my bigger charger, the motor would then turn and run. I'd like some advice on what to do to fix the problem so I can fly my pitts.