BCI method
11 amps constant current until batteries reach 16.0 volts.
Go to NAPA store buy 100 watt screw-in incandescent 12 volt light bulb. Use a hardware store lamp base.
Into the bulb base from battery pos, then out to battery pos terminal
This will throttle correct amperage for a series pair of your batteries.
Use your BIG charger. The process may take 15 hours but at the end your batteries will be at good as they're going to get.
Constant bubbling at the end. I helped write the Battery Council 'international manual. Their formula and Rolls formula are essentially the same.
This way is light-years better (faster more complete) than any other. It may bring most of your batteries back.
