I wanted to run 2 lipo's in my Inferno GT2. One is 4000mah and one is 5000mah. Both are 5s and both have a 30C discharge.

1. Is it ok to mix and match the mah when running parallel ?.

2. Will the 4000mah battery drain before the 5000mah when run in parallel or will both drain at the same rate ?.

It will work but its generally not a good idea

They will stay at the same voltage level (discharge state) during their use

In your example the current drawn will be split

5000 mah pack - 55%
4000 mah pack - 45%

Cheers

1. Yes, as long as the cell counts are the same, capacity can be diff. The C rating can be a prob if these are diff brands. There is no standard for establishing C rating and they can be diff from brand to brand. Keep an eye on temps when they're discharging, if they're truly the same C ratings, their temps should be the same. Also if there's a large age diff (number of cycles) between them, that can also cause probs.

2. They will discharge at same voltage - effectively what you're doing is creating a 9000mah 5S lipo. It will drain as such. If both are truly same C rating, they should discharge at same voltage. Again, if there's an age diff they may act differently.

You probaly could you scammer, were you run at? Maybe we run at the same places.

Both brands are the same, so I think that should be fine. Of course build date is something I will have to watch out for. Anyhow, thanks for the info!.