5S for Neu 1515 3d

[T-Bro]

Hmmm I don't know if it's safe to connect 2 lipo packs of different cell counts. I always make sure both my packs are identical if I'm running them in series.
It all depends on what you need. Runtime vs saving money. 2 packs ran in series might be cheaper but they will not run as long as 2 that are run Parallel. So I feel it's all up to your wallet.
One last pointer... running series is always better when you are racing someone or trying to reach top speed... 2 3s to make a 6s will be lighter than 2 6s packs....
Hope this helps!