4.8 and 6 v..what takes place when used at same time
I'd like to add to the melee and suggest that it really is insignificant when you consider entire scenario. Obviously you've proven that it works... I would not recommend doing so, but whatever....
1] A 6v battery has insufficient power available to charge a 4.8v battery. Fact not conjecture.
2] There are some basic considerations that should be considered.
A] The power demand will source the path of less resistance.
B] More cells is more resistance, higher static voltage discharges at a accordingly at a higher consumption rate. But there are other considerations...
C] The sum total of the battery or batteries in the case will only be as good or powerful as the individual cell with the least desirable specifications.
For the sake of discussion can you cycle the batteries, fly the model and cycle the batteries in your model and report the finding's??? I think many will be surprised...