How Long? Smart Fast Charger for 12V Lead Acid Battery, 10A

Hi. TE-108-012 is a 12VDC 10A SLA (Sealed Lead Acid) battery charger. A 20 Amp Hour battery will take 2 hours to charge with it in theory. There are a couple other things that come into play though. The battery has to be rated for that fast of a charge. Some SLA batteries are only rated for 1/3C for charging (basically 1/3 of 20, so 6.6 Amps maximum charge). So to charge a 20AHr battery you will need a 0.5C charge rating on the battery. The other thing is batteries never store exactly what they are rated for, typically it’s more… Also the charger will start to tail off the 10A rate as the battery gets charged. Also it’s not good practice to fully drain your battery, if you do the battery charger probably won’t be able to feed a full 10A to it to start. So if your battery has a 0.5C charge rating (this is a different number than the discharge rating) and it’s rated for 20Ahr, a 10A charger will probably take 2.5-3 hrs if its fully drained. If you are trying to get the most life out of your battery, don’t fully drain it and charge it as slow as you have patience for, but at least keep it below the charge ratings of the battery. Same goes for discharge, never discharge faster than the mfg recommended discharge rate to prolong the life.