charging batteries

MEXICOWANDERER wrote:
Generally speaking applying a set 14.8 volts (the instant you start the charger voltage jumps to 14
8 and stays there, allows the batteries to fill above 90% full in three to four and a half hours.

The downside is the initial charge rate has to be above 200-amps to do it this quickly. Higher capacity GC-220 batteries would demand >250 amperes. Toward the end of charge total amps would be in the forties.

My goodness, Mex, that's getting serious! We regular humans using about 25% charging rates get it done as posted in the ugly graph above, but the 90% marker then becomes when amps have tapered to about 5 amps per battery at 14.5v (so 10a with two batts or 20 amps with four)

Generally speaking applying a set 14.8 volts (the instant you start the charger voltage jumps to 14
8 and stays there, allows the batteries to fill above 90% full in three to four and a half hours.

The downside is the initial charge rate has to be above 200-amps to do it this quickly. Higher capacity GC-220 batteries would demand >250 amperes. Toward the end of charge total amps would be in the forties.

Be aware, the batteries each are rated as you say @ 200/AH. When connected in series, you still have only 200/AH.

As bfl13 said, not just amps but voltage too. At 13.6 it may take 2 days. What model is your converter or charger?

On generator you won't charge them fully since that will take all day or so. The drill off-grid is to do 50-80s or 50-90s (percentage of SOC) next, it depends on the amps and charging profile of your charger (converter most likely)

However, it is all quite predictable with Wet Cell batts, and here is a handy dandy ugly graph for three sets of amperages that all go to about 14.6v by the end. (That voltage is very important--you will take all day at 13.6 if you can't get your charger to do 14.6) You can read in between for other sizes.

Doubling the amps on the same bank capacity does not halve the time, notice. But at the same amps, doubling the bank doubles the time. So for four batteries, and the same amps double these times. It is all proportionate, so for three 12s add 50% to the times at the same amps.

100% full? 24 hours. Good enough? 6 hours. However, you have not provided me with the amperage rating of the charger.