Solar Panel Size To Battery Bank Size
When you pro's talk, having solar panels sized to battery amp size, are you referring to total battery capacity or the 50% useable battery capacity? I am working on my Solar system, I have a total hou...
Forum Discussion
CT Wanderer
"...When you pro's talk, having solar panels sized to battery amp size, are you referring to total battery capacity or the 50% useable battery capacity..."
Not a pro but a delighted user of solar. I believe that people are referring to total battery capacity and not the 50% usable capacity. Unfortunately, a lot of folks do not know the difference. I guess that your 580 AH battery suite is composed of 12 V batteries or about 7 kW-h total or 3.5 kW-h usable. You do have a 36' motorhome so you could easily install over 1 kW of panels. I think that there seems to be a rule-of-thumb of about 8 to 10 times total battery capacity to maximum solar power. Your planned ratio is about 11 so you are in the ball paark, but another one or two panels would not be a bad idea. Your panels are 12 V (more or less) and probably will be in parallel so that you have 12 V to 12 V which simplifies things.
We run 90 V from panels to battery suite since it reduces power loss, can use smaller cabling, and a smaller conroller (TriStar 45). Our battery bank is 48 V nominal.
Roy B
How do you get 600 W of solar on your popup or is that 50 amp charge rate from the generator. Absolutely agree with running generator in early morning to get the battery suite up and then let solar top off. This is what we did with earlier systems; however, we have a 34' 5th wheel with sufficient solar to top off the battery suite fairly early in the day.
Reed and Elaine
"...When you pro's talk, having solar panels sized to battery amp size, are you referring to total battery capacity or the 50% useable battery capacity..."
Not a pro but a delighted user of solar. I believe that people are referring to total battery capacity and not the 50% usable capacity. Unfortunately, a lot of folks do not know the difference. I guess that your 580 AH battery suite is composed of 12 V batteries or about 7 kW-h total or 3.5 kW-h usable. You do have a 36' motorhome so you could easily install over 1 kW of panels. I think that there seems to be a rule-of-thumb of about 8 to 10 times total battery capacity to maximum solar power. Your planned ratio is about 11 so you are in the ball paark, but another one or two panels would not be a bad idea. Your panels are 12 V (more or less) and probably will be in parallel so that you have 12 V to 12 V which simplifies things.
We run 90 V from panels to battery suite since it reduces power loss, can use smaller cabling, and a smaller conroller (TriStar 45). Our battery bank is 48 V nominal.
Roy B
How do you get 600 W of solar on your popup or is that 50 amp charge rate from the generator. Absolutely agree with running generator in early morning to get the battery suite up and then let solar top off. This is what we did with earlier systems; however, we have a 34' 5th wheel with sufficient solar to top off the battery suite fairly early in the day.
Reed and Elaine
