CA Traveler
The Western States
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My son wants to install a small solar system to maintain the 2 12V marine batteries in storage in Sacramento with above average sun. A 100W 12V panel seems right at $130.
But what controller? The Morningstar SS6L at $48 will do the job, but he would like one with a meter and the only Morningstar I see is the Duo at $146.
I'm thinking a HF DVM mounted next to the controller will give him easy ability to check the battery voltage and would meet his desire for a meter.
Suggestions/comments appreciated.
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Bob
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BFL13
Victoria, BC
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Great price for a 100w panel.
A 10 amp controller would allow for times when the solar is exceeding its rating by 1.25 as they recommend, or even more to allow for cloud effect. But that all depends on how the controller acts when met by higher amps.
My 16a just lets the amps through to the battery. I have seen 19a. If it stayed there very long the controller would warm up. So it's all a matter of degree.
You are right about the metering. The most important meter is the hydrometer, followed by the voltmeter. The controller does not need any read-outs.
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smkettner
Southern California
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I understand it may seem like a $100 voltmeter, more to install etc. And if my son was interested in electrics, batteries and solar I would get the DUO for $146 in a heartbeat. For just myself I would only get the $48 controller.
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2oldman
Winchester WA
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How long will these batts be sitting?
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CA Traveler
The Western States
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2oldman wrote:How long will these batts be sitting? I'll ask but my guess is 10+ months/year.
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pianotuna
Regina, SK, Canada
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Hi,
Since it is for storage only he could go smaller--but there would not be many savings to be had and what you suggested will be excellent. If he wants a voltmeter how about a Walmart one that reads xx.xx volts? They are about $15.00
Regards, Don
Kustom Koach Class C 28'5" 256 watts Unisolar, 875 amp hours in two battery banks 12 volt batteries, 2500 MSW watt inverter.
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2oldman
Winchester WA
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I guess if there are parasitic loads which remain connected then this plan is ok. If not, simply disconnecting one battery terminal would be fine. That said, if this storage area reached temps of 90* or above for any length of time, the solar would be better. Heat is nasty on batteries.
I'm not sure why a VOM is necessary, unless you want to see if either the panels or the batteries have failed.
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Ramblin' Ralph
Central California Coast
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I've had a 1/2 amp panel keeping 2 marine batteries fully charged on my boat for 20 years (same panel, different batteries). I live in SoCal.
Ralph
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CA Traveler
The Western States
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The estimated wire run is 27' or 54' of 10ga wire for a 1.9% drop panel to battery.
I suggested using a combiner box with a loop of slack wire to add a second future panel if desired. This would increase the wire drop to 3.5%. Since these are 12V panels and PWM controller I thought that would be acceptable.
The initial emphasis is for storage but with the possibility of expanding in the future. So part of the evolving plan is for learning. An existing voltmeter helps in that direction. A larger initial CC is also a possibility. The storage area is in Sacramento which is very warm during the summer.
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michelb
Ottawa, ON, Canada
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FWIW, if all he wants to do is maintain the battery, 100W is way more than he needs. Our 5W panel keeps our 4 batteries fresh in storage for several months in a row.
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