Solar to keep batteries charged

Adler

Well-Known Member
Last winter I had battery issues when the boat sat for more than a few weeks, and ended up having one battery replaced under warranty. I almost installed a noco charger, but with that new battery and regular spring runs, no issues. Now having pulled the boat for winter and with the possibility of not taking it out for a few months, I am back to wanting a solar panel to keep the deep cycle, and maybe the starter, topped up. I like solar better than the Noco plan because I could see using it in the summer too when out on extended boat camping trips.

I searched other posts, but what I see is mostly for those with more electrical requirements than I have. No fridge, no inverter, just 2 batteries for the motors, scottys, radio, radar and GPS. And frequent phone charging lol. I have been searching online, see some basic panels from Amazon etc. Ideally I'd like to connect permanently to the batteries and leave the cords accessible so I can hook up the panel when needed. Hopefully with longer cords too (I.e 12-15') so I can put the panel on the roof. Make sense?

Anyone else have this setup? Which panel did you chose? Suggestions? Thanks in advance.
 
Oh, I'd like to add that the placement of my batteries has a lot to do with this. On my Raider, one of the few things I don't like is that the batteries are under the step....so it takes the removal of about 12 screws to gain access. So that's why I'd like to do the permanent cord install.
 
Oh, I'd like to add that the placement of my batteries has a lot to do with this. On my Raider, one of the few things I don't like is that the batteries are under the step....so it takes the removal of about 12 screws to gain access. So that's why I'd like to do the permanent cord install.
You could stick a pig tail out somewhere to connect it when you use it. I had a Coleman solar set up on my old camper and the controller had a 6’ lead or so. Enough line to run the pig tail somewhere and the solar has like 10’ of line to run the panel somewhere else.

You don’t need a big panel to keep the batteries topped up
 
You could stick a pig tail out somewhere to connect it when you use it. I had a Coleman solar set up on my old camper and the controller had a 6’ lead or so. Enough line to run the pig tail somewhere and the solar has like 10’ of line to run the panel somewhere else.

You don’t need a big panel to keep the batteries topped up
Those suitcase systems are good for this.
 
Oh, I'd like to add that the placement of my batteries has a lot to do with this. On my Raider, one of the few things I don't like is that the batteries are under the step....so it takes the removal of about 12 screws to gain access. So that's why I'd like to do the permanent cord install.
Marketplace has the Coleman units often. Many of them were sold in packages of two, so that adds to the inventory that is often available.
 
Thanks guys for the info so far. The cords all look short, but I am looking at those options and may have to do the pigtail. I think a 10 w panel would do the trick, but ok to go to 40 w too.
 
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Have a look at Renogy stuff on Amazon, panels should be about $1 per watt delivered. Whatever you choose get an MPPT charge controller, they're a game changer compared to the old style PWM's they increase out put dramatically. Mono panels are better than poly's and bypass and blocking diodes are a good idea too in case you ever add another panel.
 
Have a look at Renogy stuff on Amazon, panels should be about $1 per watt delivered. Whatever you choose get an MPPT charge controller, they're a game changer compared to the old style PWM's they increase out put dramatically. Mono panels are better than poly's and bypass and blocking diodes are a good idea too in case you ever add another panel.
Yeah, have been looking at theirs, thanks for the info.

Hey, a while back I saw a device on here that you plug into your battery, and it sends info on battery health to an app I think on the phone. Wondering if I should add that too. Anyone know what I'm talking about?
 
get 2 x 50W flexible solar panels, glue them to your boat top or rear someplace, wire them to a Renogy voyager and add a Victron BMV 712 smart. thats all you need.
 
Those are what I refer to. The 40 watt version. They often are for sale used.

$70.


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I had one of these break in the boat, glass everywhere. The connections also corroded, so I had to throw out the charge controller. Went to a soft flexible panel and a Victron solar charger controller just because it has Bluetooth built-in.

The Victron has a Bluetooth battery monitor that monitors two batteries. I think that is what you are mentioning. There is a wired Chinese one with a gauge that is cheaper, but it only does one battery. Here's the Victron https://amzn.to/3U2edwb

https://www.solaronline.ca/product/100w-flexi-monocrystalline-solar-panel/ is what I bought, there isn't a better price anywhere for these panels. They are not as efficient as solid pannel but they don't break.

I would be concerned that a 40-50W panel could keep two batteries topped up unless it was in direct sunlight but I'm not an electrical engineer. Scottys, radio, radar and GPS have a pretty big draw and if your kicker doesn't have a big alternator, they can get pretty drawn down. Everyone says, over build your solar.
 
I installed a flexible solar panel kit that I purchased from Aztec in Nanaimo. https://www.aztecoffgrid.com/products/solar/

Excellent kits, complete with charging system monitors and real-time data on status of your charge, power available and charge rate. I have 2 house batteries and a lot of electronics, 3 riggers etc etc...huge load. My batteries could not keep up, however since installing the solar kit I have no issues with low power. Highly recommend installing a system, and the fellow at Aztec was very helpful in explaining the install and selecting the right units.
 
Just an FYI on flexible panels, they’re the least efficient and will degrade the fastest due to heat build up from no air circulation below. Heat is the enemy of output. Although they can still be the best choice in some applications, just understand what you’re getting into and size accordingly.

I wonder how one of the new bifacial panels would work on a boat? If the ideal mounting location was available seems like there would be lots of reflected light available for the backside.
 
I would be concerned that a 40-50W panel could keep two batteries topped up unless it was in direct sunlight but I'm not an electrical engineer. Scottys, radio, radar and GPS have a pretty big draw and if your kicker doesn't have a big alternator, they can get pretty drawn down. Everyone says, over build your solar.

If the boat is sitting at the dock or on the trailer, these would work like a trickle charger. I don’t think using one to keep your battery charged as you’re out trolling and draining batteries without a decent alternator is the intended purpose though.

I’ve talked to a number of owners at my marina that use them and they tell me that they keep their starting battery and spare battery “topped up” when not using the boat.

Tempered glass does tend to shatter if it breaks.
 
Just an FYI on flexible panels, they’re the least efficient and will degrade the fastest due to heat build up from no air circulation below. Heat is the enemy of output. Although they can still be the best choice in some applications, just understand what you’re getting into and size accordingly.

I wonder how one of the new bifacial panels would work on a boat? If the ideal mounting location was available seems like there would be lots of reflected light available for the backside.

thats simply untrue for aluminum boats. i have mine mounted on 1/4" aluminum sheets on the arch and they work fine. aluminum acts like giant heatsinks for flexible solar panels and the heat goes into the water.
 
thats simply untrue for aluminum boats. i have mine mounted on 1/4" aluminum sheets on the arch and they work fine. aluminum acts like giant heatsinks for flexible solar panels and the heat goes into the water.
Sure it's true, that's why you mounted yours to a heat sink.
 
Sure it's true, that's why you mounted yours to a heat sink.
And the flexible panels are virtually indestructible - you drop a fishing weight on a glass solar panel and its toast. So far my experience after 3 seasons has been really good - including how the panel keeps my house batteries topped up even when we are working them hard. An expense, but so far worth it.
 
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