I have been thinking of charging batteries at a 2C rate instead of 1C. My question is do they always need to be balance charged when going over the 1C rate? I tried searching for this but I didn't seem to find the exact answer, sorry if I missed it.

Charge rate in and of itself will not effect your packs' need for balancing.

Your packs will need to be balanced more often as they age or if you consistently run them down to cutoff or close to it or if you're having issues getting them charged all the way, etc.

I personally try to balance charge my packs as often as time allows. Cheap insurance toward the life of the pack.

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Yes I always balance my packs when I am not at the track playing.