I want to use two LiPos on my copter to increase flight time and ensure some backup. According to forum posts many simply connect two batteries in parallel. However, this does not seem to be a good idea since you always have to ensure that both batteries are almost equally charged and none of them can fail. I was thinking about some approach using diodes but then recuperation currents can not be fed back to the batteries.
Any thoughts on this? In your opinion, what is the best approach for the connection of two batteries?
Thanks in advance.