Still Don't Get It (Solar)
What will charge 2 6v golf cart batteries better, a single 270 watt high voltage panel with mppt or two 135 watt 12v panels (parallel) with PWM and why???? Thanks. Gman
Forum Discussion
Gman,
You may be surprised how much even a small load on a fairly discharged pair of 6's can pull down the voltage. Nevertheless, 2 hours of "charging" did not replace your evening and overnight usage. This speaks volumes to some, but seems perfectly normal to others.
The good news is, solar will help significantly. The bad news is, your wfco isn't charging your batteries like it should. A 55a charger, on a 208Ah bank is actually a rather high charge rate of C/3.8. You should be able to do a 50-80% (62Ah replaced) in 2 hours, no problem, and in the example you give, a 66-90%, no problem. So, if you were at 12.4v (~66%), and then charged for 2 hours, you should have been up around (and quite possibly above) 90%. So, to go from 90+% down to ~60% (12.3ish) throughout the evening and over night, that would require over 60Ah usage.
I'm not doubting your estimated usage, but I am doubting your wfco's ability to charge your bank in a reasonable manner. Let's say you used 40Ah's throughout the evening and over night, if the wfco had done its job properly, that should have brought you down from 90% to above 70%, (40Ah = 19% usage), not down to 60%. In this example then, that means the wfco only replaced about 25Ah's in 2 hours. How does a 55a charger replace only 25Ah's in 2 hours on a fairly deeply discharged 208Ah bank?
For comparison, I have done a 50-90%, on a larger bank (215Ah) with a smaller charger (45a) in just over 2 hours.
You may be surprised how much even a small load on a fairly discharged pair of 6's can pull down the voltage. Nevertheless, 2 hours of "charging" did not replace your evening and overnight usage. This speaks volumes to some, but seems perfectly normal to others.
The good news is, solar will help significantly. The bad news is, your wfco isn't charging your batteries like it should. A 55a charger, on a 208Ah bank is actually a rather high charge rate of C/3.8. You should be able to do a 50-80% (62Ah replaced) in 2 hours, no problem, and in the example you give, a 66-90%, no problem. So, if you were at 12.4v (~66%), and then charged for 2 hours, you should have been up around (and quite possibly above) 90%. So, to go from 90+% down to ~60% (12.3ish) throughout the evening and over night, that would require over 60Ah usage.
I'm not doubting your estimated usage, but I am doubting your wfco's ability to charge your bank in a reasonable manner. Let's say you used 40Ah's throughout the evening and over night, if the wfco had done its job properly, that should have brought you down from 90% to above 70%, (40Ah = 19% usage), not down to 60%. In this example then, that means the wfco only replaced about 25Ah's in 2 hours. How does a 55a charger replace only 25Ah's in 2 hours on a fairly deeply discharged 208Ah bank?
For comparison, I have done a 50-90%, on a larger bank (215Ah) with a smaller charger (45a) in just over 2 hours.
