Renogy solar charger?

Silvertip

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I don't have one but judging by the size of your vessel, the battery plant is probably sizable in which case, this unit may be marginal. Keep in mind it it's 30A output is available only in full, direct sunlight and drops quickly with clouds and is not of much value in fog or rain. Off shore it is better than not having shore power but certainly not as effective as charging from the main propulsion engines. So you need to give us a little more detail on what your expectations are as well as a little more detail about your house electrical system, Is AC power available at the slip? Do you anchor for long periods where there is no shore power? Do you not have an onboard generator?
 

NYBo

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ST, the controller is rated for 30A. The panel puts out only a fraction of that- the ad says 5.65 amp is optimal output. Think trickle charger territory.
 

H20Rat

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I have that EXACT same kit on my RV... Works great! Even without aiming the panel and leaving it flat, I'll see almost 5 amps. Also puts out a fair amount of power in cloudy conditions. I dry camp exclusively so no plugins ever. I do have a generator but generally I don't need to run it or the main, the single panel will keep the batteries up for 2-3 days of camping. (may add a second panel next year, I camp late in the season and the furnace draws lots of power)

So... Couple things to keep in mind. The connectors used are good connectors but are proprietary and require a special crimper. I just spliced the cables and didn't mess with the connections. Use heavy wire! I used 8 gauge. It isn't that there is that much current, you want heavy wire to keep voltage drop to a minimum. The charge controller is very basic. No numeric display, but you can add one for under $10 from ebay.
 
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K-2

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Thanks! I No power @ slip, one 8D starting battery and two ,T105 Trojan 6V deep cycle in series for house power, twin engines so an alternator for each bank.
WHat I want this solar charger for is to trickle charge both banks all winter and help charge the T-105's when tied up for a few days and no engine running,
at that point there will only be a 12V fridge running, it is a new one so does not draw much. Can I make either of my "wants" work with this charger?
 

Silvertip

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Arrrrggg. My bad -- blew right past the "controller" and had the 30A stuck in this old brain. I agree that the panel would work to keep the batteries topped off during periods at the dock. That is until you mentioned keeping the 12 volt fridge running. If the fridge current draw is 1/2 or more of the 5 amps panel output then the house battery would be losing ground since there is no output from the panel at night. Is it an option? Certainly! Is it a 100% solution? Doubt it. One other thought is that unless the slip is secure, the panel is not and it won't last long before Johnny Lightfingers makes off with it.
 

K-2

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Thanks for the help! Now I know it's limitations and I think I will give it a try. One more question :
Can I leave it all wired and in place when I start the engine and the alternator starts charging?
 

H20Rat

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The charger sees the voltage on the battery side, so if that goes up because you are charging either through the alternator or shore power, the solar current is shut off. But as mentioned above, I'd check on the draw of the fridge. If it is a thermoelectric model, those things can suck an amazing amount of power for not much cold...
 

UncleWillie

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Oct 18, 2011
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Heating or cooling use a lot of power.
A panel that delivers 5+ amps in full sun should be treated as a 1 amp 24 hours a day panel.
And that is an optimistic assumption.
5 amps are only 60 watts and 1 amp is 12 watts.
I doubt that any fridge averages under 1amp/12watts. A candle is 80 Watts.

Keeping a full battery topped off, Yes!
Operating any equipment larger than an LED reading light. No!
 

K-2

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The fridge is a little over 2 amps, 2.2 or something,,, remember the sun is up a long time in Alaska during the summer. If I'm using 2+ amps and gaining back 1+ amps then my batteries will go dead about half as fast. I'm good with that. That's the house batteries not the starting batteries. And the fridge will not be left on always, sometimes I empty it out and take everything home and shut it off. Thanks
 

H20Rat

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Heating or cooling use a lot of power.
A panel that delivers 5+ amps in full sun should be treated as a 1 amp 24 hours a day panel.
And that is an optimistic assumption.
5 amps are only 60 watts and 1 amp is 12 watts.
I doubt that any fridge averages under 1amp/12watts. A candle is 80 Watts.

Keeping a full battery topped off, Yes!
Operating any equipment larger than an LED reading light. No!


Think of it this way, you are increasing the size of your battery by 24 amp hours per day... No, it isn't enough to power the fridge, but it does extend the capacity quite a bit. That is how I use mine for dry camping, I know I'm going to eventually end up out of power (down to 50% battery capacity), the solar is just there to get me through the weekend.
 

UncleWillie

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Every Little bit helps!

I suspect that if the Fridge only draws 2.2 amps, that would be at 120 volts. Equivalent to 22 amps at 12 volts.

The real issue is the OP is going to be using it in Alaska.
Alaska is not known for more than 90 Sunny days a year.

The panel is rated for 100 watts with a Bright Sun at Noon, under a Dark Blue cloudless sky, like you see right after a cold front passage.
A light blue hazy sky is going to reduce the output noticeably.

The spec also assumes that the panel is pointing directly at the Sun.
Most of Alaska is above 60 Degrees North.
The Summer Noon Sun on Jun 21st is barely 40 degrees above the horizon, and lower the rest of the time.
Placing the panel on a flat surface is going to limit its output to well less than half.
Tilting up 40-60 degrees and pointing it due South will help.
The Alaska Sun tracks through a lot more sky than it does in Florida.
The Sun rises in the North East, Passes due South, but nowhere near Overhead, at Noon, and sets in the NorthWest.
It spends a good portion of each day North of an East/West line.
Pointing it South and leaving it will not make good use of the limited output.
A mount that tracks the Sun throughout the day would be justified.

Solar panels for this application are just not to be recommended.

I'll might suggest that a wind generator, like used on sailboats, might be more successful in this application.
They naturally align themselves with the wind, operate at night, and work especially well during storms.
 

K-2

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Apr 3, 2011
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The fridge is a NovaKool, they use a 12 volt Danfoss compressors. It's small, 2.4cubic ft., draws 2.1 amps max, averages 15 amps per 24 hours.
The DC compressors are very efficient. The old Norcolds that suck amps like crazy are as popular as Loran C . We are at 59.22 North. I will check into wind generators but I think I'm just going to add another set of T-105's, double my amp hours.
 
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