Most of the newer "smart" chargers are of the pulse charge variety, which are great for desulfation, but they have a "sense" circuit which must see 1.5 to 2.0vdc before they will turn on and start charging. If you run into a completely dead battery, sometimes there is a way to get a smart charger to work. If you have a second (charged) battery nearby, try connecting it to the dead battery in parallel and let them remain connected for a few minutes. The two batteries will begin to equalize and the dead one will accept some charge from the other battery. Once the discharged battery has enough charge voltage, you can start the smart charger and finish the charge.I have a NOCO G3500 I use on my KTM. I connected the NOCO to my Interstate wet battery in my Cherokee - it wouldn't charge it. So I used my old reliable Schauer 10A and it brought it back to life.
NOCO Genius G3500 6V/12V 3.5A UltraSafe Smart Battery Charger https://www.amazon.com/dp/B004LWVEKS/ref=cm_sw_r_cp_api_Dbd.ybRSS7QK5
Hey Buddy -I might pick 1 of these up for my Optima yellow tops
:happyyes:Hey Buddy -
Look into Optima's charger, should meet/exceed manufacturer recommendations for proper charging/maintenance (I'd probably go 12 Amp version):
Can't reiterate enough, check with your battery's manual for what charge voltage it recommends. I looked up the manual for this charger and it does not state what voltage it uses, it just notes 12.2-12.7V "needs charging", I don't know if that means it only applies a voltage of 12.8V or what. The Odyssey charger I linked earlier costs twice as much, but it is clear in the manual:I don't know if this is the "best" charger, but I have been using this Schumacher charger for several years now and it works great. It works on 6v and 12v batteries. It also charges standard, AGM and gel batteries and it has a battery maintenance mode. They are $41 on Amazon.
During this mode the “Charging” indicator will be red. The charger will
use all of its available charging amps (as controlled by temperature) until the battery voltage is raised to 14.7VDC.