The Sterling Pro Charge Ultra or the Pro Mariner Pronautic P are both excellent chargers that come standard with temp sensors. Remember 14.4V is max voltage for the Firefly, temp compensated... Demand is very high for the Firefly AGM right now and like Rolls batteries these are hand made.... I have confidence they will catch up...Greetings Maine Sail, The Firefly batteries are pretty scarce. I just bought the last 2 available in CA. The dealer said they are tooling up to manufacture more very soon to meet demand. My question is...what charger would you recommend I get to go with these batteries? I am redoing me electrical system and want to get it right. I already have heavy duty cables and a couple of as yet unused distribution blocks.