That means your 4200mah battery is going to "die" soon. For a healthy 7.2V battery charging at a constant current at 4A, the peak voltage should occur at around 9.x, close to 9.0 is better.
That means your 4200mah battery is going to "die" soon. For a healthy 7.2V battery charging at a constant current at 4A, the peak voltage should occur at around 9.x, close to 9.0 is better.