How big of a solar panel do I need?

[DMurdock]

I want to maintain my batteries in storage (this is NOT for boondocking). I disconnect the house (4x6v) and then gen (1x12v) so the only loss is what happens when they are just "sitting there".

Here's how I plan on wiring it (45w panel is just a guess but you get the idea).

FYI - the panel will not be mounted on the bird (mounted on the roof of storage barn once I get it finished)..

I plan on tapping into the charging lines next to the xantrex and installing quick disconnects. If any of this looks fishy let me know...I'm an electrical amateur

thanks!

[Arcticdude]

I don't know if 45W will be enough to keep all 3 banks up. You've only got 3.75A at maximum ( if its a 12V output), splitting that 3 ways and accounting for inherent losses will leave maybe 1A per bank. Is that enough? I don't know. One of the smarter folks will be along shortly to more thoroughly answer your question.


Maybe a better question is why bother with the solar? With 3 decent smart tenders, you'll draw less than 1A of 120V most of the time. How long will it take to just recoup the cost of the solar panel, much less a decent controller?

[DMurdock]

No A/C Power available...

[davidbrady]

(09-20-2013 01:12)Arcticdude Wrote:  Is that enough? I don't know. One of the smarter folks will be along shortly to more thoroughly answer your question.

John, pending one of the smarter guys, I'll take a swing.


Hi DuWayne,

What are the ampere-hour capacities of your battery banks?
What's the average daily sunlight that you expect to see?
What's the peak amperage of your solar panel?

[DMurdock]

I'm going out there Monday to work on the barn/cover..I'll find out then!

[DMurdock]

232 x 20hr?

These are the batteries I have (there are 4 of them, 2 banks of 2x6v

http://www.interstatebatteries.com/cs_eS...olt%7C3%7C