Just bought a Nexpeak 10A charger off Amazon. Figured I should have a battery charger (didn't have one) and will probably rarely use it as our cars get driven often. But, you never know. Was looking at load testers/battery testers (I have a multimeter so can read volts) that are cheap but tell more than lights for "excellent, good, bad." But if there aren't decent cheap ones I'll just continue having them tested yearly at the dealer or auto stores for "free".