Solar

[Colo_Native]

I am getting ready to install solar system on my new to me DP I am looking at 2 255 watt Sainty Solar panels off craigslist here. I am considering using a renogy 40 MPPT rover elite controller. I put a system on my old FW and I went all out on that but trying to save a buck. II also have a question about installing on a fiberglass roof(Winnebago) do I use screws and Dicor or 3M tape and some dicor? I went to look in the archives for my old system but it has disappeared from here. The MH already has a Magnum Inverter installed. As always thanks for the help

[Colo_Native]

2oldman wrote:

Colo Native wrote:
Also on the batteries I have 4 12v is the pos hooked up at one end and neg to other? It's been awhile since I did solar.

How is your converter hooked up?

Not sure what you are asking.

[Colo_Native]

MEXICOWANDERER wrote:

Colo Native wrote:

Lwiddis wrote:
“The panels are sitting in a guys garage...”

Not comforting. You need a heck of a discount from him.

they are new never used and he wants $180 for each which I think $150 would be fair. But I will run a volt test to make sure

AMP TEST

SHORTED + to -- not connected to anything.

Mere volts will tell you nothing.

Already bought the 300w panels and they test fine.

[Colo_Native]

time2roll wrote:
40 is fine with 600w of solar.

Good to know. Thanks

[RJsfishin]

2oldman wrote:

Colo Native wrote:
Also on the batteries I have 4 12v is the pos hooked up at one end and neg to other? It's been awhile since I did solar.

How is your converter hooked up?

Sounds like you are describing series hookup wich would be 48 volts.

[2oldman]

Colo Native wrote:
Also on the batteries I have 4 12v is the pos hooked up at one end and neg to other? It's been awhile since I did solar.

How is your converter hooked up?

[MEXICOWANDERER]

Colo Native wrote:

Lwiddis wrote:
“The panels are sitting in a guys garage...”

Not comforting. You need a heck of a discount from him.

they are new never used and he wants $180 for each which I think $150 would be fair. But I will run a volt test to make sure

AMP TEST

SHORTED + to -- not connected to anything.

Mere volts will tell you nothing.

[time2roll]

40 is fine with 600w of solar.

[Colo_Native]

Ok I found 2 brand new 300w panels for $300 so I went with them. I am thinking now that I should go with a 60 amp controller or would a 40 still if I remember the 40 had a 600w max. Also on the batteries I have 4 12v is the pos hooked up at one end and neg to other? It's been awhile since I did solar.

[Colo_Native]

Lwiddis wrote:
“The panels are sitting in a guys garage...”

Not comforting. You need a heck of a discount from him.

they are new never used and he want $180 for each which I think $150 would be fair. But I will run a volt test to make sure

[Colo_Native]

My old system on the FW was 510w solar with a 45 amp tristar and it worked fine. I agree with them laying flat I doubt they would over produce the controller.

[BFL13]

Using 7 flat vs 8 aimed ratio (based on some tests I did in May at 49N)
for amps output at high noon starting with aimed--

510w with 10% heat loss = 459w with say 2% line loss array to controller= 450w input with say 5% controller loss = 428w output. Amps to battery is output watts/battery voltage, so: (with no line loss controller to battery)

428/12.5 = 34.2a and 7/8 of that is 30 amps estimated
428/13.5 = 31.7a and 7/8 of that is 28 amps estimated

[time2roll]

KD4UPL wrote:
Sorry guys. I had a typo with the 310 watts, it's obviously 510 watts of PV, But the amps is still the same: 510 watts / 12 volts = 42.5 amps.

40 amp MPPT is perfectly good for this set-up. Actually a 30 would be fine. Only very rare conditions would produce close to 40 amps.

[2oldman]

510w of solar will rarely if ever hit 510w. Maybe 400.

[KD4UPL]

Sorry guys. I had a typo with the 310 watts, it's obviously 510 watts of PV, But the amps is still the same: 510 watts / 12 volts = 42.5 amps.