I'm using 2 2cell 7.4 volt Thunder Power 5200 50C LiPo packs in a series connection. I've never used more than one LiPo in my cars, so this is new and confusing to me. I'm not sure where I should set the LiPo voltage cutoff at.

And just so you have an idea, I plan on running a Mamba 2650kv motor in a truggy based road car.

set it on 4s

So the cutoff would be set at 14.8volts?

Not meaning to be a smarta$$, but have you read the instructions?

http://www.castlecreations.com/suppo...s_ed_guide.pdf
(See page 30)

Leave it on the default Auto-LiPo setting (2.) It will detect the number of cells and cut the thing off when the pack reaches 3v/cell (12v in the case of your 4S setup.) If you wanted to you could use setting 6, but I see no reason to.

It is important to note that the ESC is just averaging the voltages so you should try to make sure all the individual cells you are using are pretty closely matched.

I thought about leaving it on Auto, but setting it manually, I'll at least know for sure. And the batteries have never been used, they're still at storage votage and all matched. I'm just trying to cover all my bases before I race this thing.

I leave the cell detection on auto and count the beeps when I switch it on to make sure it got it right. I do bump the cutoff voltage up to 3.4v per cell. IMO 3.0v per cell is way to low. Even at 3.4v per cell I can tell the car slowing down a good bit on the last lap or so before the cutoff kicks in.

After ruining at $170 pair of SMC lipos last year from having my LVC to low on my Flux, I set mine to 3.5v to give more breathing room to prevent another costly incident like that.

Heavier MT like a HPI Sav Flux - 3.5v/cell is a good lvc, helps protect your lipos where there are big voltage demands. If your RC is lighter can go with a lower lvc, like 3.2v/cell. I use 3.2v/cell in my Slash.

Using the auto lvc setting even with a specified voltage has one quirk - if you run your lipos down in one session and quit, turn it off, unplug and then come back later to finish without recharging, you can get into trouble. Say you've dropped the voltage enough and when you come back to run somemore, the MMM thinks this is a 3S since the voltage is low enough. The lvc setting on 3.5v/cell will now be applied to a 3S and the MM will allow you to run this 2nd time down to 3 x 3.5 = 10.5v which is fne for a 3S, but will seriously risk damaging a 4S that shouldn't go below14v.

The only clue you get is the number of beeps the MMM makes when it powers up - you would only hear 3 this time and not 4. I never run again without recharging, but this is an easy way to damage lipos. Its something you wouldn't think about. Always pay attention to the MMM when it counts back the number of lipo cells and if its the right number, it doesn't matter. If its one too few, do something before you damage your lipos.