Help with Basic Solar Set Up

[BurbMan]

After years of storing the TT at home we are thinking of moving to a smaller home and putting the TT in a storage lot. One of the luxuries of parking at home is being able to stay plugged in year round and keep the batteries charged up. So I am looking for a small solar set up that will give me enough of a trickle charge to keep the batteries topped up.

Currently have 2 6v batteries that are 8 years old and will likely get replaced this season at some point. I have been looking at Solar for a few years but moving to a storage lot would be the impetus I needed to pull the trigger.

What's a recommended solar set up to keep the batteries charged? Assuming there might be 3 or 4 cloudy days running on batteries, the solar would need to "catch up" and bring the batteries back when the sun comes out. Usage would be minimal...propane detector, idle radio (clock display), about it, and whatever other small draws.

From what I gather I would need a solar panel and a charge controller, any recommendations for size or brands for this application? Is scaling up to add wattage simply a function of more panels?

[BurbMan]

Good point....according the info I have the PD4655 converter goes into "equalization mode" automatically for 15 mins every 21 hrs to equalize the batteries.

[Almot]

Amazon is not the place to look for solar kits 100W and bigger. Check Solar Blvd

You don't need more than 40W for storage, considering 232 AH bank. You "might" need more watts for equalizing, but then again you can do it when you are on shore power. Equalizing only takes a few hours and you don't do this every day.

[pianotuna]

Hi red31,

5% of capacity (c/20) is the bare minimum for equalization to take place.

For 79 amp-hours 48 watts will equalize.

Where I live, temperature compensation is a "must do".

[red31]

Don, do you really need that much power to equalize when used as a maintainer?

I have 60 watts for a 79 ah battery based on that recommendation and it's twice my usage when not stored, I'd need to connect directly to get above 14.8v. That is right in the ball park of JCI's 2-4 A @ 16.?

[pianotuna]

Hi,

Kits are often over priced. The smaller the bank the more watts per 100 amp-hours of capacity are needed.

The range of size for 232 amp-hours would be 140 watts to 348 watts.

[BurbMan]

So if I have 232 AH battery capacity then I need 60 x 2.32 = 139.2 W solar capacity?

Would something like this 140W kit work? Aside from the wattage, what attributes am I looking for in the panels and controller? Is it better to get a kit or buy individual components?

[pianotuna]

Hi,

12.5 watts per 100 amp-hours of storage is the very least.

60 watts per 100 amp-hours is enough to equalize the battery bank.

With panel prices in decline it may actually be cheaper to buy a larger wattage panel than a smaller wattage.

I would not skimp on the controller.

[BFL13]

I don't know the size of solar set you would need for that job, but whatever, disconnect the rig entirely by removing a wire from the battery bank so only the solar controller is on the bank. You don't want any draw opposing the solar trickle.

Smk on here is always worried about how long the controller would keep the batts at 14.x each day while doing storage. You want to drop to Float voltage as early in the day as possible, so finding a controller that will do that is important.