Solar power and circuit breakers - Page 3

Greg A · 11-03-2019, 12:20 AM

Nicely planned and executed. You’ll will get a huge power improvement on the road with this setup. I like the use of the under seat as well, good out of the box idea.

**John in Santa Cruz** · 11-03-2019, 02:28 AM

I've never had my 2 6V golf cart batts much below 12.4V or so....

Mike Lewis · 11-03-2019, 08:29 AM

Quote:

Originally Posted by Greg A

Nicely planned and executed. You’ll will get a huge power improvement on the road with this setup. I like the use of the under seat as well, good out of the box idea.

Thanks. I got the idea of mounting stuff under the seat when I put the radio there a couple of years ago. That seemed to work okay, so I figured that stuff I might need to access on a regular basis such as fuse blocks could go on the lid as well. They would be easier to get to.

Although I tried to visualize how things would fit together with the lid closed, I did screw up a few times. Initially I had the big terminal post for the batteries on the lid. But after raising it a few times I decided that flexing those big cables was not a good idea, as it would put strain on the battery terminals (which of course must be made of platinum, right?). So I cut a board to put on the upright supports and mounted the stud to it. This meant rotating the radio 90 degrees so its wires wouldn't conflict with the board, etc.

I admit that the lithium batteries are an expensive indulgence. But as with many such purchases it was driven by psychology. I'm really reluctant to mess with lead-acid batteries, especially in the close confines of the trailer. And since I'm reluctant to maintain them, I avoid the task. I had ruined one set of batteries this way and could see the cycle continuing. I didn't go for AGMs due to the weight issue, as I might want to add more batteries in the future. I've mounted the lithium batteries so that I can add more, and/or a larger inverter, if I strike oil or win the lottery.

Jim Bennett · 11-03-2019, 09:31 AM

Quote:

Originally Posted by Mike Lewis

I used 6 gauge wire to the controller because that was the largest gauge it would accept. Coincidentally AM Solar used 6 gauge wire coming down from the rooftop panels. The connector for a portable panel had 10 gauge leads. I connected the 6 and 10 gauge wires to the 50A breaker and terminal stud via ring connectors, then used 6 gauge wire from the breaker and terminal to the controller.

You certainly have a great setup there, Mike. You will be well served.

I do wonder why the use of #6 wire is such a short run. You could have more than 1000W running at it's full capacity (which never happens) with that size cable. I could see if you have a longer run from the panels like in many home setups. I need edumacating here.

Though, I too bought into saving energy lost savings by using running two panels in series and producing twice the voltage with half the amperage. What I actually save is very, very minimal with a 12' run to my controller. My maximum amperage with 240W is only 6.7A at 36V, but I have never seen near that. I was getting a bit over 5A once (I now forget the actual amount) with my 80W portable aimed right at the sun. With my portable stolen and now looking for a replacement I do have to find a two panel setup I can convert to 3VV, though considering rewiring the mounted panels all in parallel at 18V.

Tin · 11-03-2019, 10:05 AM

Wow, very nice Mike looks like a boon docker delight

. I see you installed a dc to dc charger for two battle borns

. is it a 30 amp or 60 amp ? again nice setup.

Mike Lewis · 11-03-2019, 10:17 AM

Quote:

Originally Posted by Jim Bennett

You certainly have a great setup there, Mike. You will be well served.

I do wonder why the use of #6 wire is such a short run. You could have more than 1000W running at it's full capacity (which never happens) with that size cable. I could see if you have a longer run from the panels like in many home setups. I need edumacating here.

Not much thought went into selecting the #6 wire. I did it only because that is what came down from the rooftop panels to the controller, so I continued the same gauge from the controller to the batteries. I didn't do any calculations. I think AM Solar used the #6 wire because the original plan was to have four panels on the roof, but I'm guessing.

I will also use AWG 6 wire from the B2B charger to the truck, in this case due to distance (40 ft.) and amperage (30A) involved. I'm concerned about the batteries' ability to send 400 amps down that wire in case of a short. I will re-read Jon V.'s postings on how he fused his line to prevent this before I proceed.