Taman

iTrader: (67)

Hi, I'm new to this and I have a Speed Passion GT2.1EX which I using with a Thunder Power 1S 5000mAH 40C li-po, what do I set the low voltage cut-off at? I tried teh Speed Passion thread but no answer so hopefully someone here can help

thanks

malinios

3.2 volts is kinda the accepted lower end for li-po. Some of the newer formulations can handle 2.8v as a deep discharge, but generally it's safer to cut em at 3.2v. Li-po discharge is a plateau with a steep drop off at the end, when you notice that the punch is falling off quickly, best to cut it off yourself and recharge. Li-po does not like deep discharge and it will effect the life of the battery. Now and again taking it to the cutoff is no big deal, everytime you run the car WILL have detrimental effects on the cells.

Taman

iTrader: (67)

Thanks for the quick reply, appreciate it

the lipo is only 3.7V, so you only get .5V out of it before you have to recharge it?

malinios

Li-po charges to 4.2 volts and is "nominal" at 3.7. Meaning that under load you'd expect to see 3.7 or so volts from the cells when you are spinning the motor. The voltage should hold close to the 3.7 mark throughout the cells rated capacity (mAh) and when the capacity is exhausted the voltage will drop quickly , that is where the "edge' of the plateau is. Li-pos do not act like alkaline or lead/acid batts in that the voltage drops inline with the capacity, the voltage is sort of a fixed aspect while the capacity is what makes the big changes. Look at some discharge graphs for lithium based cells and it'll make sense. If you are familiar with nickel based batteries (NiCad for instance) the discharge graphs will look familiar.

Taman

iTrader: (67)

thanks very much I understand now