What is a battery tender?
A Battery Tender is an aftermarket 24v charger that charges, and floats/maintains 24v SLA battery packs. The Tender tends to be less expensive than the MINDer, but lacks the desulfation logic. Of course, if you are agnostic about the desulfation magic then you wouldn’t want to pay extra for that anyhow. If you go the Tender route you will likely use the 24v Battery Tender Plus, although the 5A current seems a bit high to me. Plus, btw, refers to the additional logic for AGM batteries added after the original BT charger was released. I do not own a 24v Tender, though I do have a 12v Tender for my motorcycle which works fine.