ezwryder
New Member
Just thinking out loud here. I’d appreciate any thoughts you might have about this: I want to expand my solar set up with additional storage and a few more panels for a faster recovery time.
I currently have 6 x 100 watt panels going into a Victron 100/30 amp charge controller. The controller charges two SOK 206 Ah heated batteries wired in parallel. When the controller maxes out at 30 Ah, the charge rate is about 15 Ah per battery. If I add a third, I would expect 10 Ah per battery.
I want to increase the recharge rate to 25 Ah per battery if I can, but I also want to avoid an overcurrent charging situation. I know there was a paper written about this and I cannot find it anywhere. I don’t recall if it had suggested remedies but I do know it clearly illustrated the potential issue.
Here’s what I think my options are.
Option 1: Swap out the existing 100/30 controller I have for a 100/50 (which I also have). My present panels max out at around 425 watts because of the charge controller 30 amp output limit. Even without adding panels, a 50 amp controller would better use all the power from the current panels, producing another 12 to 14 amps. 44 Ah into 3 batteries is 14.6 Ah, close to the present recharge rate of the two battery setup.
Option 2: Swap out the 30 amp controller for the 50 amp controller AND add two panels. The approximate max amp output of the panels would increase to 56 amps which would be capped at 50 with the 100/50 controller. That’s 16.66 amps per battery, a small increase.
Option 3: Use both the 100/30 and the 100/50 with the appropriate number of panels. If I did this I could put 80 amps into the batteries which is about 26.6 amps per battery.
I like option 3 but I am concerned about what might happen if two batteries reach the charge cut-off point before the third is fully charged. That would present a potential total of 80 amps to the third battery. I know each battery BMS has overcurrent protection but I would rather avoid having to rely on that.
Maybe this is an uncommon condition if the batteries are kept fairly well balanced and I am overthinking? Or maybe there are other ways to mitigate the potential issue?
Thanks for any thoughts you might have.
I currently have 6 x 100 watt panels going into a Victron 100/30 amp charge controller. The controller charges two SOK 206 Ah heated batteries wired in parallel. When the controller maxes out at 30 Ah, the charge rate is about 15 Ah per battery. If I add a third, I would expect 10 Ah per battery.
I want to increase the recharge rate to 25 Ah per battery if I can, but I also want to avoid an overcurrent charging situation. I know there was a paper written about this and I cannot find it anywhere. I don’t recall if it had suggested remedies but I do know it clearly illustrated the potential issue.
Here’s what I think my options are.
Option 1: Swap out the existing 100/30 controller I have for a 100/50 (which I also have). My present panels max out at around 425 watts because of the charge controller 30 amp output limit. Even without adding panels, a 50 amp controller would better use all the power from the current panels, producing another 12 to 14 amps. 44 Ah into 3 batteries is 14.6 Ah, close to the present recharge rate of the two battery setup.
Option 2: Swap out the 30 amp controller for the 50 amp controller AND add two panels. The approximate max amp output of the panels would increase to 56 amps which would be capped at 50 with the 100/50 controller. That’s 16.66 amps per battery, a small increase.
Option 3: Use both the 100/30 and the 100/50 with the appropriate number of panels. If I did this I could put 80 amps into the batteries which is about 26.6 amps per battery.
I like option 3 but I am concerned about what might happen if two batteries reach the charge cut-off point before the third is fully charged. That would present a potential total of 80 amps to the third battery. I know each battery BMS has overcurrent protection but I would rather avoid having to rely on that.
Maybe this is an uncommon condition if the batteries are kept fairly well balanced and I am overthinking? Or maybe there are other ways to mitigate the potential issue?
Thanks for any thoughts you might have.