How about solar charging
Here's someone doing a solar generator/charger for his vruzend battery https://www.youtube.com/watch?v=ucK1HF9g7zc&t=10s
Be sure to buy Micah’s new book about DYI solar projects....
DIY Solar Power: How To Power Everything From The Sun https://www.amazon.com/dp/098990671X/ref=cm_sw_r_cp_api_6UqIAbEWRJQJ6
I have not finished reading it but it is a great resource. As far as using solar to charge home made battery packs, check out the picture below. I am new to the DYI battery pack and solar charger world but it was not too difficult for me.
I am in the process of ordering 2,500 cells to add to my solar system at home. I already ordered 5,200 vruzend blue&red caps for this project, but I don't know when they will be off backorder. My solar setup is a 5,000-watt, 48V system which already has (16) 12v flooded and AGM batteries on it. I will be building (11) LI-ion batteries using (224) 18650 cells each, 14 across in series and 16 down in parallel for each of the batteries. I might have to go with 15 in series, but I'll start with 14 and see how it goes. Most 48V solar systems run between 47V and 59V.
Hopefully we'll be shipping again in less than a week. The kits have successfully cleared customs and we are just waiting for them to get trucked to our shipping center in Florida now. Sorry for the wait!
Micah has the same problem as Tesla.... great product with huge demand. Not a bad problem to have. 🙂