Solar Help from EEs and Others Please

[ruscal]

Deborah,
Not a solar expert or EE, just a solar user.
I am using 2 100W portable panels with a 45a MPPT controller. The system works really well, and often we don't need to put out both panels to recharge our single group 27 battery in just 2 hours. You may find that the need for 4 panels is too much for the single battery. You could add more battery capacity or reduce the number of panels depending on how far north you are and how much tree cover you have at the camping area. There are ways to size this stuff published on line.
You can connect the negative lead from your onboard charger to the shunt as well, to monitor its output on the Trimetric.
Sizing fuses is to protect devices and the wire. If your controller is 45a, you could protect that with a 60 amp fuse, and the wire if sized to carry 45a could be protected with 45 amp fuse, but you will want to upsize the wire to lessen voltage drop which improves charging. If you upsize the wire you would size the fuse to protect it, and it may be well above the 60 amp fuse needed to protect the controller, so you would be fine with the 60 amp for both.
Russ

[blodn1]

Thanks Peter - I've been all over the map trying to figure out what to do, since there doesn't seem to be a packaged system that meets my needs. Added to that, there's a lot of conflicting info.

Didn't know how to draw the solar panel setup - I want to duplicate what you did (from an earlier post) and what you just described.

I want the A/C and the microwave only for hooked up applications - and will be in that situation only rarely. But I do want the option.

I'm looking at a pair of 6V 200 AH batteries, so in series, shouldn't I have 400 AH? Actually, I don't even need a microwave, but want the capacity to add one in the future.

My biggest energy users will be the 12V fridge, my computer, 12V lighting and pump, and a Keurig mini (doesn't continuously heat water). I will have a TV, but I rarely watch, so it's occasional use. Composting toilet, if I decide to go that way, has a solar fan, so no electricity or water.

Great advice on the transfer switch. I opted for drawing it, because several web sites said it was necessary, and what do I know?

[Bob Miller]

Despite the issues raised, drawing out a schematic for critique is an excellent way to get your hands around a problem and find out how to solve it.

Don't get discouraged, start reworking what you have and, long before your Lil' Snoozy is in the driveway, you will have an electrical system all laid out that will do everything you want.

And that's a whole lot better than depending on Joe at Acme RV to do what you want to accomplish, and to do it right the first time.

[blodn1]

Thanks for the encouragement Bob. That's exactly what I intended.

[Briantb]

Start by first determining your projected energy usage.. It can be done with a spreadsheet available from many sources. You can figure out the consumption for your appliances manually either with generic figures readily available online, or calculate it using owners manual information and compliance stickers on item.
You can also by an inexpensive kill o watt meter such as this and measure actual consumption (these numbers might surprise you.. Especially the mini Keurig)

http://Amazon.com/gp/aw/d/B00009MDBU...&pi=SY200_QL40

[Mike Magee]

Deborah, based on your projected items using DC power, I would say that 200W would be plenty. Two panels of 100W each, plus a controller, going into a pair of batteries. 2 6V golf cart batteries in series would work well. BTW, when you wire them in series you will get 6+6=12V, but the 200A will stay the same. (If wired in parallel, you'd retain 6V but get 400A; however, 6V won't run your 12V appliances, so that's out.)