I use Life with sanwa rx, normal futaba (9451 and bls451) servo no issue. FS with savox not sure.... But it should be ok too. BTW: do not change the LiFe in LiPo mode..... Must switch to LiFe mode. Cutoff voltage is different.
Sorry for confusing some of you in my previous post, I'm using 5 cell Nimh battery, not Life nor Lipo, my apology. Btw, before my using 9V to charge, I did use multimeter to check my another charger the voltage much higher than the battery's (and get some info from web about Nimh/Nicd quick/slow charging approach), so it should be a 'safe' experience to go ahead.