Solar help... Mppt or PWM
Hi.. I recently got a new solar panel from somewhere... fell off truck... lol I know mppt is the way to go im mysituation but am asking for advice... panel 250 watts volts 30v. Wh...
Forum Discussion
lawrosa wrote:
Normally with that small amount of use I am 12.2 volts by morning...
Two 75 AH batts so 75 ah for the day...
Sounds normal. With your loads I would expect 40-50 AH daily draw, depending on laptop or TV time. 12.2V - without load? - means you are using ~ 60 AH a day. If it's 12.2V under load, then you're using 50 AH. Furnace will make a big dent in this. I replaced furnace with propane heater, silent and no amps draw.
Single 250W flat in summer... where, in NJ? 70-80 AH a day maybe, when it's sunny. 2-3 times less in winter. 10 times less when it rains all day. You should be OK with flat on the roof in summer. But you said you mostly park in the shade, - this isn't good.
Eco has no temp sensor to adjust battery voltage when ambient changes, so it assumes that it's 77F always. When it's hot you have to lower the voltage, but this controller won't unless you change settings manually. So... try keeping batts in shade when in summer. In winter the voltage should be raised, but again Eco won't.
No, Rogue don't make anything anymore. Their 20A units is a left-over. I mentioned my 30A just to illustrate that you "can" have 500W with 30A MPPT (or, in your case, 250W with 15A) when panel is flat, temps above freezing and you are at sea level.
