Hi! I was wondering if it would be possible to connect two 5000 mah 3s 20c batteries in parralel and two 4000 mah 5s 30c batteries in series. Is this possible to achieve a 10,000 mah 10s 40c battery?
Thanks!
That’s really not a good idea
What would not work?
Is it just that you can’t do that.
2 x 3s § is still only 3s
2 x 5s (s) would be 10s
You could series those two up for 13s but any other combination won’t really work.
The problem is putting two 5000/20 batteries in series with two 4000/30 batteries because they have different capacity and discharge rates.
They won’t drain equally in series.
What if you have one set of batteries connected in series an one connected in parralel?
Cant connect a 10s ( (2) 5s in series ) to a 3s ( (2) 3s in parallel ). If im not loosing my mind the 10s would try to balance out with the 3s and the 3s will go bang and burn your house down 
What should i do with the extra two 3s batteries? IS there anyway to include them in the build?
Best bet is to ride them separately. But you may need to change your settings if your using a VESC. Ride with a 6S setup, Ride with a 10S setup.