Charging a Battery Bank
I am planning on upgrading my batteries to 4 6v batteries wired in series and parallel to have a 12v system with plenty of Amp Hours. There is a ton of information on how to wire things up but nothing...
Forum Discussion
Harvey51 wrote:BFL13 wrote:
The four batts will not "demand" a limited amount of amps in bulk. Forget that notion, please :( The 440AH bank will "accept" at least 160 amps at 50% no sweat, so don't worry about that.
I am confused about this. I think it might indicate there is a solution to my problem with a 25 year old 3/4 ton GM van which is rarely driven more than 4 blocks between starts. The battery doesn't fully recharge and gradually sinks to the dreaded 12.0 volts in winter here in northern Alberta. The new alternator is supposed to be good for 90 amps. It does apply 14.4 volts to the battery. It seems to me the battery should recharge fully at 90 amps for 15 minutes after a start. If the battery does not have an internal resistance limiting its acceptance of current, what is the limitation? Is it the cable from alternator to battery? If so, I can get a second cable and double the rate of charging! Maybe the cable connectors are corroded and a simple replacement will solve the problem. Or does the 14.4 volts on the battery mean all is well with the cable?
Not up on starting battery recharging, but the 14.4 volts is good. The 15 minutes is not enough time, that's all. The van needs to be kept on one of those engine battery maintenance chargers between trips like they have for motor homes.
I use one of these (wait till they come on sale again for half price or whatever) It sits at 13.4 volts forever after starting off at 14.2 for a short time.
http://www.canadiantire.ca/en/pdp/0111506P.html
I was referring above to deep cycle batteries which will accept the high amps until they get up in voltage at say 75% SOC when amps will then taper for some hours before the batteries are full.
I don't know how long it takes for a starting battery to get to true full after it reaches near that 14.4 volts, but it will take a while. Also the alternator voltage drops from that 14.4 soon after starting, which slows down the recharge.
The main point is that the battery does not accept the 90 amps until it is full. It only accepts high amps till it is part full, then amps taper for the Absorption stage which takes some time.
