Solar

Ed_Gee wrote:
I must add to those who have already commented on this. Sounds like a fine solar charging system ... BUT way too little battery capacity for that much charging capability. Your batter capacity ought to be at least double.

AS stated I will change Batteries later as these are less than 1 year old.

JiminDenver wrote:
No games, just options and their consequences.

My decision was't because of what happens when one of the panels are shaded, we don't get a lot of shade up there. It was because I would lose up to 10 amps at peak in series and have a hot running controller for it.

As for shading and shadows, the test I ran last year showed that in series a weaker or weakened panel will weaken the whole string and confuse the controller. Other panels may differ.

Now I have three panels that at altitude will have more than 30 amps coming down in parallel. That's more than MC4 10 gauge gear can handle so I have 1/0 welding wire for the job. Over kill yes but it was cheaper than a thinner gauge new. With two panels you really wouldn't have to spend much more for the difference in wire needed for parallel vs series.

I'm hoping to reseal our roof before the install, that is if we don't get a foot of snow this weekend.

I don't think we'll get snow but it is Colo. Jim one concern as you stated is heat and if I go with parallel I surely would need to run larger wire down from the j box correct? Series is easier I believe but what is more efficient? I have solar on the house and if one is shaded then the whole system has a lower output but one a RV its charging batteries

I must add to those who have already commented on this. Sounds like a fine solar charging system ... BUT way too little battery capacity for that much charging capability. Your batter capacity ought to be at least double.

12thgenusa wrote:
Try it both ways and see which works best for you. Not much battery for that amount of solar.

If I run parallel then do I need larger wire from the combiner box (then 10awg) for series.

2oldman wrote:
Why don't you expand on what you're not sure about, that way we don't have to go thru the 5 pages of litany on series vs parallel.


Series v parallel

Is there really any big difference in one way over the other?

red31 wrote:

JiminDenver wrote:
I would lose up to 10 amps at peak in series and have a hot running controller for it.

actual or based on the curves in the back of controller manual?

Actual

The panels peak at 18.5a each or 55.5a. The best I saw in series was mid 40's.

JiminDenver wrote:
I would lose up to 10 amps at peak in series and have a hot running controller for it.

actual or based on the curves in the back of controller manual?

If parallel is better it probably will not be enough to notice in general RV use.

Series just makes the wiring easier in many cases. But if the panels are mounted right next to each other it is probably just as easy to use some MC4 parallel connectors. Then also easy to switch parallel to series each day if you like.

+1 to add battery capacity. May not need AGM so much with solar.

Try it both ways and see which works best for you. Not much battery for that amount of solar.

No games, just options and their consequences.

My decision was't because of what happens when one of the panels are shaded, we don't get a lot of shade up there. It was because I would lose up to 10 amps at peak in series and have a hot running controller for it.

As for shading and shadows, the test I ran last year showed that in series a weaker or weakened panel will weaken the whole string and confuse the controller. Other panels may differ.

Now I have three panels that at altitude will have more than 30 amps coming down in parallel. That's more than MC4 10 gauge gear can handle so I have 1/0 welding wire for the job. Over kill yes but it was cheaper than a thinner gauge new. With two panels you really wouldn't have to spend much more for the difference in wire needed for parallel vs series.

I'm hoping to reseal our roof before the install, that is if we don't get a foot of snow this weekend.