RE: Is my RX pack ok?
Hi!
I sure sounds as if one or two cells in your battery pack are bad.
To really know I would buy a multimeter and check the voltage (under load) on each cell in the battery pack. You do this by sticking needles through the plastic into + and - on each battery cell.
Each cell should give 1,25V fully charged.
If you find one cell (or several) that shows only 1,0V the whole pack should be discarded.