Just about this time last year, I took delivery of a couple of SOK 12-volt, 206-amp/hour, LiFePO4 batteries in metal enclosures. I’d ordered them well before the van arrived, as SOK had none in stock, and no one knew when more would be available. They arrived a few months later, and are untouched, still in their sealed shipping cartons.

Our design has changed to use 24-volt batteries (sticking w/SOK, just more volts), so now these are extra. One has been sold, the other is available. I paid $1029 apiece a year ago. One year later, still brand new and unused, I'm selling it for $900, shipping included. I've been in contact with SOK, and the warranty is still in full force, and will be for the next six years, in my hands or in the new owner's.

You can get a full run-down on it here.