I had these and had the same battery problem. I ordered some replacement batteries and replaced the one that was having issues. They were great again for a while. Then the other one started having issues. Then I accidentally damaged the ribbon cable while taking that one apart. Now they’re junk. I’m still pissed about it. It would have been so easy for them to make replacing the batteries easy.

The dream seems to be solar panels across the top and onboard electrolysis, and fuel cells. Then the same hydrogen that keeps you afloat is also your energy storage. A compressor to store extra hydrogen also seems like a good idea. I imagine we can make these into closed systems.