Connecting Different Sized Batteries?


I know it’s a good idea to have all things equal, so that the load is balanced between all sources… However presently I have two Bonka 22AH and two Tatu 18AH batteries. Should I attempt to fly in this config, or be patient and wait for my other two Bonkas to show?

If the consensus (on an internet forum… I know) is to combine them, what would be the ideal combo in parallel?


you can put the 22Ah and 18Ah in Parallel and have 40Ah in total. It’s not a problem to do it, as long as the Voltage is the same.


As Etienne said.

You need to make sure the matching batteries are in series with eachother. The two Bonkas together in series and the two tattu in series. Then you can put those strings in parallel with one another.

Being in parallel they will be at the same voltage and discharge together, regardless of their differing capacity.

What you want to avoid is combinations where two different brands / capacities / internal resistences are in series with one another. That will lead to the smaller of the two being overdischarged and ruined.


GASP An agreement! Thank you both so much! Now to hone my soldering skills…