RF: Tonight's project, converting a 40A DieHard automotive battery charger to handle my SLA battery pack. Mainly adding some 10awg leads to an Anderson Power Pole socket to charge them in parallel.
SC: Just remember to open the series connections first!
JP: Stephen Chapman what exactly are you referring to?
SC: If you have two batteries in series and then connect them in parallel to the same charger without opening the series circuit, you will create a dead short.
RF: Handling that on the receiving harness side. The battery pack harness will have 6 Powerpoles in parallel (3 +, 3 -). Charger will be the same, so I can charge in parallel (or float/charge any of the 3 individual cells). The car will have 6 Powerpoles as well, but wired in series to pull 36V (and probably at least one 12V tap for some lights)
SC: Randy Farmer, that is the smart way to do it. For my 36V yard tractor I use three 12V Soneil 5A charger/desulphators hooked up one across each battery. The Soneils are isolated unlike most consumer grade chargers which use autotransformers. Autotransformers are grounded on the DC side and that shared ground gets folks in trouble. http://soneil.com/content/1212sr-1