Advice on deep cycle setup?
Hello, I have a Safari van that I've converted into a camper. I replaced the starting battery with a Duracell Ultra Dual Purpose (Starting/Cycling) Battery that cost $105 (got it at batteries ...
Forum Discussion
Panel specs need to be checked anyway using your meter. They can be just wrong. EG, I have two matching 100w panels made in India and one 100w panel made in China.
I previously had some 12v panels and noted that their Iscs were in proportion wrt their watts. EG 130w-8.2 and 120w-7.6 and 80w-5.1 and 100w was 6.3 and those Isc values were what I actually got as amps to the battery on good days, panels aimed. Eventually sold those panels and got others.
So the "Coleman" 100w (supplied by SunForce to Can Tire) had 5.8 amps on the box and its label on the back of the panel had:
Voc 21.5, Vmp 17.1, Imp 5.8 No Isc mentioned.
Sure enough aimed at the high sun, meter showed Isc as 6.3
Then I got the two (one year old) India 100w panels at a garage sale. Their label specs say Voc 22.7, Vmp 18.8 , Imp 5.3, Isc 5.8
I wanted to use all three so I checked the India ones in the sun and got Isc 6.3 and the warmed up panels showed Voc as same as the warmed up Coleman panel. So have been using all three either in series or parallel with no issues.
Using my Solar30 PWM I get 18.6 amps to the battery. Using the Tracer or Eco-W MPPTs I get about the same 17-18 amps either in parallel or series. ( Neither 20amp MPPT has ever been seen clipping its amps at 20 amps with the 300w panels. They get hot and never have enough output in watts to get 20 amps on a battery while camping. By the time the sun is high enough to get full watts, the battery voltage has climbed so that keeps the amps down under 20)
Moral of the story is that you should check the actual Voc and Isc before deciding different brand panels won't work together with a particular controller. (Of course when shopping you can usually just go with what the specs say--no way to check them yourself)
EDIT--that low light thing where the 24-12 MPPT is getting some amps while the 12-12 PWM is not is sort of a bogus "advantage" since the low light amps are so low the AH gained is trivial. It is the old story of "percentage of what?" You can get twice as many amps! 2 instead of 1 Golly, that is 1 amp more for how many hours? 6? ok you just won 6AH for six hours of solar time. Wheee. :) )
I previously had some 12v panels and noted that their Iscs were in proportion wrt their watts. EG 130w-8.2 and 120w-7.6 and 80w-5.1 and 100w was 6.3 and those Isc values were what I actually got as amps to the battery on good days, panels aimed. Eventually sold those panels and got others.
So the "Coleman" 100w (supplied by SunForce to Can Tire) had 5.8 amps on the box and its label on the back of the panel had:
Voc 21.5, Vmp 17.1, Imp 5.8 No Isc mentioned.
Sure enough aimed at the high sun, meter showed Isc as 6.3
Then I got the two (one year old) India 100w panels at a garage sale. Their label specs say Voc 22.7, Vmp 18.8 , Imp 5.3, Isc 5.8
I wanted to use all three so I checked the India ones in the sun and got Isc 6.3 and the warmed up panels showed Voc as same as the warmed up Coleman panel. So have been using all three either in series or parallel with no issues.
Using my Solar30 PWM I get 18.6 amps to the battery. Using the Tracer or Eco-W MPPTs I get about the same 17-18 amps either in parallel or series. ( Neither 20amp MPPT has ever been seen clipping its amps at 20 amps with the 300w panels. They get hot and never have enough output in watts to get 20 amps on a battery while camping. By the time the sun is high enough to get full watts, the battery voltage has climbed so that keeps the amps down under 20)
Moral of the story is that you should check the actual Voc and Isc before deciding different brand panels won't work together with a particular controller. (Of course when shopping you can usually just go with what the specs say--no way to check them yourself)
EDIT--that low light thing where the 24-12 MPPT is getting some amps while the 12-12 PWM is not is sort of a bogus "advantage" since the low light amps are so low the AH gained is trivial. It is the old story of "percentage of what?" You can get twice as many amps! 2 instead of 1 Golly, that is 1 amp more for how many hours? 6? ok you just won 6AH for six hours of solar time. Wheee. :) )
