Can anyone tell me at what point I need to change out batteries on a Spektrum DX2S? I've been using 4 x 1.5v AA and changing them when they get to 5v, but I've got 4 x 1.2v rechargable AA and was wondering if 4.8v is already to low for consistent operation.
I have put them in and they work but I'm not keen on trying it during race conditions incase they die...

I run Eneloops in my DX3S and they are fine down to 4.4v

I get 8 hours or so before I bother topping them up

Cheers