For 12v Noco is most well known probably but kind of expensive. The Genius10 can charge 6v regular or AGM and 12v regular, AGM, or lithium. I think they’re at least good quality, I have had several for a really long time. The other thing I like about them is the X-Connect system they have. I have pigtails permanently installed on some batteries and then can just hook the charger up to that. Could make your own with SAE connectors but I’m lazy and SAE connectors are kind of shitty in my opinion. Even for that though there is X-Connect to SAE so you can connect to your charger to anything.