From what I understand, used-up lithium batteries are fairly non-toxic and can be safely dumped in a landfill. Still not zero-cost, but probably about as low a

From what I understand, used-up lithium batteries are fairly non-toxic and can be safely dumped in a landfill. Still not zero-cost, but probably about as low as you can get. And they can probably recover some of that cost by recycling some of the other metals from them.