Solar Boat Battery Charger/Maintainer Help

[retired chem teacher]

I have a building that I keep my 18 ft Lund Fisherman in that has no electricity.  I have a 4000 watt generator in the building but don't like running it long enough to charge trolling motor batteries (2-12 volt -group 27 flooded) .  Would like to put solar panel on building to charge batteries after use and maintain them when they are fully charged.  Boat is not used daily but would like batteries ready to go when needed.  I have watched countless you-tube videos and still am confused as what is the best way to go and not break the bank.  Main concern is should I try to charge both batteries when connected in series (24 volts) or charge each separate like the onboard charger does?  Also, not over charging batteries when they are fully charged.  Any recommendations and personal experience on panels, charge controllers, wiring ,etc  on size and brands would be a big help to a "solar newbie"

[fishinwrench]

No experience with solar powered anything......But definitely charge them individually. 👍

[snagged in outlet 3]

I don’t have power here at the condo so I bought a Jackery Explorer 1000 with solar panels.  I plug my onboard charger right into the power station.   After a full day on the water it will recharge 2 group 27’s easily.   Sometimes only using 50 percent of stored power.  
 

I recharge it in my condo but at home I put the solar panels out.    You could buy a 1000 watt power station and a couple panels from harbor freight to mount wherever you want and be charging the power station all the time.  
 

Then just plug in your boat.  You can recharge and plug in for power at the same time.   Several guys here saw my setup and bought the same thing.  Works great!!!   Plenty of YouTube about power stations.  
 

In the picture you can see it only took 45% to recharge my batteries from yesterday.  

[jdmidwest]

3 hours ago, snagged in outlet 3 said:

I don’t have power here at the condo so I bought a Jackery Explorer 1000 with solar panels.  I plug my onboard charger right into the power station.   After a full day on the water it will recharge 2 group 27’s easily.   Sometimes only using 50 percent of stored power.  
 

I recharge it in my condo but at home I put the solar panels out.    You could buy a 1000 watt power station and a couple panels from harbor freight to mount wherever you want and be charging the power station all the time.  
 

Then just plug in your boat.  You can recharge and plug in for power at the same time.   Several guys here saw my setup and bought the same thing.  Works great!!!   Plenty of YouTube about power stations.  
 

In the picture you can see it only took 45% to recharge my batteries from yesterday.  

That would work on my camping trips.  I normally spring for an electric site to charge the batteries.  Sometimes, can't even find  a plug at the motel to run a cord to.  I would have not thought about using a battery powered backup to charge a battery,  I would have thought it would be weak in the amp ratio.

[retired chem teacher]

So the Jackery unit is basically an inverter --correct?? --

[snagged in outlet 3]

3 hours ago, retired chem teacher said:

So the Jackery unit is basically an inverter --correct?? --

I don’t know.  You can charge it via solar or an outlet in your house and in my case my truck.  Then you can plug in anything you want to power up or charge.   Lamp, I used it for my air compressor on a low tire and I plug in my on board battery charger.  

[jdmidwest]

Its a battery powered inverter with a pure sine wave.  Clean output for electronics.

[MrGiggles]

5 hours ago, snagged in outlet 3 said:

I don’t know.  You can charge it via solar or an outlet in your house and in my case my truck.  Then you can plug in anything you want to power up or charge.   Lamp, I used it for my air compressor on a low tire and I plug in my on board battery charger.  

Likely just a lipo battery with an inverter. They seem to keep the specifics under wraps and only give a 1000w/hr rating. Given that, you could put 250 watts into your batteries for 4 hours (at 12v that would be 20ish amps divided into however many batteries you have) with it. May or may not be enough to top up your trolling batteries, would depend on how many you have and how depleted they are.

I was going to suggest a 100ah lipo battery, inverter, and a solar charger, which you could just plug your onboard charger into. It would also allow you to run some simple lighting or other electrical circuits in the building. The Jackery does two out of three and is conveniently packaged, plus has other uses, not a bad choice.

You could save some efficiency losses by cutting out the DC-AC-DC conversions, but I don't know how you could do it in a way that would allow you to charge each battery individually in a convenient, neat manner. A multi-bank solar charger would be what you want, but I'm not that familiar with solar setups. 

[snagged in outlet 3]

11 minutes ago, MrGiggles said:

Likely just a lipo battery with an inverter. They seem to keep the specifics under wraps and only give a 1000w/hr rating. Given that, you could put 250 watts into your batteries for 4 hours (at 12v that would be 20ish amps divided into however many batteries you have) with it. May or may not be enough to top up your trolling batteries, would depend on how many you have and how depleted they are.

I was going to suggest a 100ah lipo battery, inverter, and a solar charger, which you could just plug your onboard charger into. It would also allow you to run some simple lighting or other electrical circuits in the building. The Jackery does two out of three and is conveniently packaged, plus has other uses, not a bad choice.

You could save some efficiency losses by cutting out the DC-AC-DC conversions, but I don't know how you could do it in a way that would allow you to charge each battery individually in a convenient, neat manner. A multi-bank solar charger would be what you want, but I'm not that familiar with solar setups. 

I’m certainly no electrician but it works perfectly for me. I charge it in the condo while fishing. Come back and put it in my battery compartment and plug in my onboard charger.   Rarely is it ever fully drained and my green light is a blinkin in the morning.  Rinse and repeat.  
 

I got down here and my spare triggered the low tire pressure warning.   Whipped out the Jackery and my portable compressor and aired it up.  Like I said I don’t know all the jargon but it works perfectly for me.  

[jdmidwest]

The problem with a solar panel system only would be charging your batteries after you get done fishing.  Unless you are a morning only guy, darkness would hamper the plan of panels direct to trolling batteries.  You would have to collect on separate battery during day while fishing and use inverter of evening when you are done.