All you need to know. Read it for yourself: http://www.cncengines.com/rcexelcdi.pdf

II) 6.4 Volt Li-Fe(A123) Packs
2cell Li-Fe(A123) The Volts Max of 7.2
volts. Nominal 6.6 Volts, use a voltage
regulator. Or connects one IN4007 diode
to fall voltage the use.
If engines not highest rotational speed,
Also may directly use


I don't know why this question keeps coming up for the 10 millionth time when you can get the facts straight from the horses mouth. lol. No offense to the OP! I use 1x IN4007 diode in line on the + wire. $0.05 in cost, less than 1g of weight, and chance of failure is almost nil as I've been posting for several years now...

Egan