ORIGINAL: EloyM
The battery manufacturers (Sanyo, Panasonic etc) recommend that all cells in a battery be of the same brand, same type and of the same capacity. Otherwise, all cells will not charge optimally and may not produce their full rated capacity.
The life of your complete investment - airplane, engine, radio, etc. depends on good batteries, it is not a good idea to experiment or gamble with them. Batteries are cheap, airplanes etc are not.
You are probably right, but this isnt for a high profile model, the 4 cells are(JR) Sayno, and the 5th cell is also a Sanyo and are all 700 mah, i will do a cycle before i try it out tomorrow.
I just want the added security of having a 5th cell. Not too long ago on one of my 5 cell packs, i lost a cell, if that would have been a 4 cell pack i would have lost the plane, thanks to my Voltwatch II i saw it in the red zone, and immediately took that bad pack out. It read about 5.56 v which is what a nicely charged 4.8 pack should yield.