IDEA...charging house battery(set) underway.
It seems that the chassis alternator/VR system will often not fully charge the house battery(set) due to voltage drop between the two, or overcharge, boil the electrolyte away, for a deeply discharged...
Forum Discussion
smkettner wrote:BFL13 wrote:
Jeez PT, let the OP answer first. He may have been hitting the batts when so low that they can only accept 3 amps, with 90 amps, and no way to refuse. "Boiling over" might be the result.
I have hit plenty of batteries down below 10 volts with a shop charger on high max (15 volts?). The battery resistance is so high when dead they only accept a few amps and do not boil (gas). They just sits there. As the sulfate ions get back into solution the amps start to climb.
Shop owner said I should do the slow charge to avoid damage and turn the knob down. I replied worst case I will sell a battery as it is already shot. In the mean time I don't have all day to babysit this stuff and crank it back up.
Yes, I have brought quite a number of lawn tractor type batteries back to life with patience, 2-3 days on a charger. Very few "chargers" will force enough current flow to cause a serious level of outgassing.
Vehicular alternator/VR systems on the other hand....
