Looks to me you analyzed your issues correctly. However try to maintain a 5% of total amp hour constant current. This is so important. A 50 watt 12 volt light bulb wired in series with the positive OR negative charge lead wire will render good enough control for a 100 ampere hour battery and a 100 watt bulb or two fifties in parallel will work fine for 200 amp hours capacity. Limit finishing voltage to 16.0
I have a hunch many are trying to rush the process with higher uncontrolled amperage. This is bad juju for too many reasons to list.
