I fully agree being able to build your own DIY batteries is indeed very solarpunk. I only wanted to clarify that we allow non-literal BIFL suggestions, as you mentioned that all personal ev's are not technically BIFL (which is true).
The replies you are receiving are not from slrpnk.net accounts, but instead are from off-instance, likely from people who simply subcribe to this BIFL comm or saw it in in the /All view, and who do not consider themselves solarpunks.