LVC with 2x 2s lipos on MMM question

[FullMetalGrave]

I plan on running 2x 2s lipos in series on my Maxx once I get my MMM. I've read the posts about ESCs that have two battery inputs and you set up the lvc through the BEC side of the controller but the MMM looks to only have one battery input which is where I would plug in my series adapter. To my understanding, the controller will see 4s and cut off voltage at the correct level.

My concern is what if one battery discharges faster/deeper than the other (for some reason, just a hypothetical at the moment) and one battery remains high enough in voltage to prevent the LVC from kicking in? Is this even something to worry about or will both batts stay close enough together in voltage that when the lvc kicks in I'll be ok. I can't seem to find anything refering to this situation....

Thanks for any help, I dont' want to screw anything up and start ruining batteries left and right

[suicideneil]

Well, if they are good lipos, then you have nothing to worry about. If they are MA packs, you have every reason to worry, lol. You assumptions are reasonable, but in principle, if the packs are both charged to the same voltage, then the drain on them will be equal; only a weaker cell or cells in either pack would cause you issues. As it is, the simple solution is to just raise the LVC voltage a little, thus ensuring that even if one lipo drops its voltage a little more than the other, the total combined voltage will hit the cutoff point before any damage is done. So, rather than using the auto lipo setting, use a custom cutoff voltage of about 12.8v (3.2v per cell), or perhaps a little higher at 13.6v (3.4v per cell).

You should know already though if one of your packs has cells that are prone to being out of balance- it will show up on the charger display if you select individual cell voltages and check them before and after charging.

[Unsullied_Spy]

I have 2 Deans male connectors on my MGM 16018 so I don't even need a seires adapter. Using my 2 2s8k Maxamps lipos it works very well and they stay balanced properly as well. When I switch to a single pack I have a jumper that I put on the other plug (just a female plug with a wire looping from one contact to the other).

[FullMetalGrave]

Exactly what I was looking for. Thanks guys!

The packs I'm ordering will be the Enerland Hard Case packs (not sure if I want the 5000 30c or the 5100 25c but it will be one or the other.

[lincpimp]

It is a good idea to set the lvc for 3.2v per cell, so 12.8v for 4s. You will not notice much difference in runtime, and it will help if one pack discharges faster than the other. I run a bunch of dual pack setups and have always used this method.