Solar Panels for battery charging
Hi - we have a 1998 Fleetwood Angler 8'. I am wondering if anyone here has installed a solar power kit for charging the battery. I have not put in an auxillary battery and don't like to hook in to m...
Forum Discussion
This is not "rocket science" here folks. The amount of Solar and reserve battery power is based on three things:
1. How much energy do you use?
2. How much usable daylight do you have?
3. How long do you plan on parking in one location?
The "simple test" (only need DVM) is to go camping, arrive and setup camp (I usually keep the truck running while I do this) and then after you shut off your truck (and before you start switching DC loads on) with a DVM measure your battery voltage to ensure you have a good full charge. (there are voltage "state of charge" charts available on the web)
Finish setting up camp and "camp normally" by using whatever fans, lights, furnace, whatever that you normally use and goto bed. The next morning (after the sun comes up) before you start turning DC loads back on take your DVM and measure your battery. Compare the voltage reading to the "state of charge" chart we looked at earlier.
If you've used much less than 50% of your battery capacity at this point you can stay parked where you are, "camp normally" using whatever DC loads that you normally would and all you have to do is keep an eye on the TIME as you'll want to take another voltage reading 24hrs after arrival to see how much energy you use in a 24hr period.
To make things simple, there are three different readings you can have: 1) you used MORE than 50% of your battery capacity, 2) you used 50% of your battery capacity and 3) you used less than 50% of your battery capacity.
If your 24hr usage was >=50% capacity you need more battery capacity. In a "perfect world" cycling your leadacid battery to 50% charge ought to be rare.
Next, whatever AH you used out of the battery you'll want to replace with Solar. Granted, you may not have the roof space for this so here's where we factor in "how long are you going to stay?" into sizing the Solar.
If your only staying overnight or 2 nights over a weekend you don't have to replenish all the energy you used out of the battery - just try to keep the state of charge above 50%. So if you use 25% in a 24hr period without Solar your going to be at 50% charge in 48hrs.
Worse case in Oregon we get sun 8am-4PM - a whole whooping 8hrs of usable daylight. (your location might be worse)
Where I live officially "check in time" is 4PM and check out time is 1PM. If I arrive and setup right at 4PM Friday and stay until ~noon Sunday I won't have ANY charging light Friday, a full 8hrs Saturday and 4hrs on Sunday. A whole whooping 12hrs of charge time which if I can coax +2A of charge current I'll make up 25AH of battery charge by the time I start my truck Sunday.
Personally I think a 40-50W solar panel would be plenty in the above situation.
If I was staying all week then that is a different story, I'd want to replace ALL the 25AH capacity I used and would have to do it in a mere 8hrs or less. (Saturday) Here I think a 80-100W solar panel would be plenty in the above situation.
If I was using more than 25AH a day, I'd need more battery and more solar.
YMMV, the above works for me.
1. How much energy do you use?
2. How much usable daylight do you have?
3. How long do you plan on parking in one location?
The "simple test" (only need DVM) is to go camping, arrive and setup camp (I usually keep the truck running while I do this) and then after you shut off your truck (and before you start switching DC loads on) with a DVM measure your battery voltage to ensure you have a good full charge. (there are voltage "state of charge" charts available on the web)
Finish setting up camp and "camp normally" by using whatever fans, lights, furnace, whatever that you normally use and goto bed. The next morning (after the sun comes up) before you start turning DC loads back on take your DVM and measure your battery. Compare the voltage reading to the "state of charge" chart we looked at earlier.
If you've used much less than 50% of your battery capacity at this point you can stay parked where you are, "camp normally" using whatever DC loads that you normally would and all you have to do is keep an eye on the TIME as you'll want to take another voltage reading 24hrs after arrival to see how much energy you use in a 24hr period.
To make things simple, there are three different readings you can have: 1) you used MORE than 50% of your battery capacity, 2) you used 50% of your battery capacity and 3) you used less than 50% of your battery capacity.
If your 24hr usage was >=50% capacity you need more battery capacity. In a "perfect world" cycling your leadacid battery to 50% charge ought to be rare.
Next, whatever AH you used out of the battery you'll want to replace with Solar. Granted, you may not have the roof space for this so here's where we factor in "how long are you going to stay?" into sizing the Solar.
If your only staying overnight or 2 nights over a weekend you don't have to replenish all the energy you used out of the battery - just try to keep the state of charge above 50%. So if you use 25% in a 24hr period without Solar your going to be at 50% charge in 48hrs.
Worse case in Oregon we get sun 8am-4PM - a whole whooping 8hrs of usable daylight. (your location might be worse)
Where I live officially "check in time" is 4PM and check out time is 1PM. If I arrive and setup right at 4PM Friday and stay until ~noon Sunday I won't have ANY charging light Friday, a full 8hrs Saturday and 4hrs on Sunday. A whole whooping 12hrs of charge time which if I can coax +2A of charge current I'll make up 25AH of battery charge by the time I start my truck Sunday.
Personally I think a 40-50W solar panel would be plenty in the above situation.
If I was staying all week then that is a different story, I'd want to replace ALL the 25AH capacity I used and would have to do it in a mere 8hrs or less. (Saturday) Here I think a 80-100W solar panel would be plenty in the above situation.
If I was using more than 25AH a day, I'd need more battery and more solar.
YMMV, the above works for me.
