TrailManor Owner's Forum - View Single Post - Converter with adjustable charge current?

**Bill** · 12-17-2021, 10:22 AM

Rick -

If the batteries are connected in parallel, is there any guarantee that a given charge current will divide equally between the two parallel batteries? I can imagine (but I have no experience) that when you first turn on the charger, small differences in the batteries could result in a large current imbalance, meaning one battery will charge harder than the other. This will even out, of course, as the initially-lower battery comes up to match the other. But in an extreme example, an initial 100-amp charge might divide unequally - say 75 amps/25 amps. Could this be dangerous to the batteries? Will the BMS in each battery take care of it?

I think you are telling me above that the BMS will take care of it, but you seem to attach some caveats to that statement. Will the BMS forcibly reduce the current in the 75-amp battery, down to something acceptable? Or will it simply disconnect the battery that is being charged too fast - in which case, that battery doesn't get charged at all.

I know nothing about LiFePO4 batteries, so you will be educating me.

Thanks

Bill

12-17-2021, 10:22 AM	#6
Bill Site Team Join Date: Feb 2003 Location: The mountains of Scottsdale, AZ, and the beaches of Maine Posts: 10,104	Rick - If the batteries are connected in parallel, is there any guarantee that a given charge current will divide equally between the two parallel batteries? I can imagine (but I have no experience) that when you first turn on the charger, small differences in the batteries could result in a large current imbalance, meaning one battery will charge harder than the other. This will even out, of course, as the initially-lower battery comes up to match the other. But in an extreme example, an initial 100-amp charge might divide unequally - say 75 amps/25 amps. Could this be dangerous to the batteries? Will the BMS in each battery take care of it? I think you are telling me above that the BMS will take care of it, but you seem to attach some caveats to that statement. Will the BMS forcibly reduce the current in the 75-amp battery, down to something acceptable? Or will it simply disconnect the battery that is being charged too fast - in which case, that battery doesn't get charged at all. I know nothing about LiFePO4 batteries, so you will be educating me. Thanks Bill __________________ 2020 2720QS (aka 2720SL) 2014 Ford F-150 4WD 5.0L Bill's Tech Stuff album