Solar powered battery charger?

[Evildwarf]

I'm sure this has been discussed before but since I have the attention span of a hyper active squirrel I probably missed the pertinent facts.
Could someone with experience please offer some practical advice on a solar powered battery charger.
I would be charging/maintaining a deep cycle battery for powering the bilge pump in a slip with no access to electricity.

 

[jonw9]

I was considering the same thing for my lift.

Currently I am leaning towards a Battery Tender, and the cigarette lighter adapter.

I am thinking 10 Watt:
http://www.amazon.com/Battery-Tende...im_auto_7?ie=UTF8&refRID=1A5CR125VCJRAFK5QXNK
http://www.amazon.com/Battery-Tende...im_auto_2?ie=UTF8&refRID=1PWEVG36Z3QXZM2H3YWH

 

[OrangeTJ]

I had the $35 six watt one from Home Depot plugged into my 12v outlet while we had the boat slipped for about. 6 weeks. Worked like a charm. Left bilge switched on and we always had a good charge on boat battery when we came down to use it.

 

[ToddW850]

@jonw9 and @OrangeTJ these are great ideas. I'm currently hooking up my DieHard battery charger every time I want to top off my batteries before going out. And I hope I don't sound stupid, but I didn't realize you could charge your battery through the 12v outlet plug. My plan was to run the clips to actual battery. But a 12v outlet would be much easier. So my question is, is there any risk of damaging anything like electronics?

 

[Bruce]

@jonw9 and @OrangeTJ these are great ideas. I'm currently hooking up my DieHard battery charger every time I want to top off my batteries before going out. And I hope I don't sound stupid, but I didn't realize you could charge your battery through the 12v outlet plug. My plan was to run the clips to actual battery. But a 12v outlet would be much easier. So my question is, is there any risk of damaging anything like electronics?

It is fine to use the 12v outlet for charging as long as you do not exceed the rated capacity of the outlet. I used a 1.5 amp (20 watt) charger connected to the 12v outlet for over two years until I installed an onboard charger.

 

[Jayr212x]

I'm investigating doing the same thing. I'm looking for a 10-15 watt panel that I attach to the top of the wakeboard tower while the boat is in the slip. I have two batteries that I would like to maintain so I'm looking into a dual battery solar charge controller like this:

http://www.amazon.com/Battery-Charg...keywords=dual+battery+solar+charge+controller

The solar charge controller is supposed to prevent over charging or discharging.

Keep us posted on your final set up.

 

[cane.mba]

If you have a battery cut-off switch, will the battery have to be on in order to charge through the 12v outlet?

 

[thcole]

This is the one I currently have mounted to my wake tower. It seems to work pretty well even though I am having a battery issue now but I believe my battery is about 8 years old.

http://www.pulsetech.net/12V-ERV-UNIT-SolarPulse-ERV-12V-Solar-Charger-Maintainer-6Watt-7301.aspx

Small and packs a big punch.

 

[jonw9]

If you have a battery cut-off switch, will the battery have to be on in order to charge through the 12v outlet?

That is something you will have to check. On my boat, I (accidentally) realized that certain things (bilge, blower, radio memory) stay energized when the switch is off. So connecting tot he lighter will work. This will make it easier to connect as I don't need to open the engine hatch or put in some through hull plug.
The same way on some cars the lighter works without the key, and some need the accessory power.

 

[Island Jay]

Solar is great for applications where you do not have ac power for a smart onboard chargers. The drawback is the low amps for charging fast. Usually it is days for a full charge vs hours from a smart charger with an AC source. But if it suits your needs, why not?

 

[Evildwarf]

Solar is great for applications where you do not have ac power for a smart onboard chargers. The drawback is the low amps for charging fast. Usually it is days for a full charge vs hours from a smart charger with an AC source. But if it suits your needs, why not?

Presently I keep my accessory battery on to run the bilge pump while in the slip.
I have a small battery tender hooked up to AC power to keep the accessory battery topped off.
Any issues with charging while the battery is under load?

 

[Island Jay]

It really depends on the charger and draw, but most likely, yes. Battery chargers can either charger while under load or not. Usually trickle chargers and waterproof chargers cannot charge while supplying power as they are not designed for that. Some at best could put out an amp or two, max for shore power. They will burn out with more. Most dry mount chargers are designed to provide shore power while charging. It is their purpose.

Your best bet is to call the factory that makes your charger and ask what the max load can be on it while charging. Compare that to your draw and make sure the draw is 20% less than the chargers output for supplying power while charging (If any).

 

[Evildwarf]

It really depends on the charger and draw, but most likely, yes. Battery chargers can either charger while under load or not. Usually trickle chargers and waterproof chargers cannot charge while supplying power as they are not designed for that. Some at best could put out an amp or two, max for shore power. They will burn out with more. Most dry mount chargers are designed to provide shore power while charging. It is their purpose.

Your best bet is to call the factory that makes your charger and ask what the max load can be on it while charging. Compare that to your draw and make sure the draw is 20% less than the chargers output for supplying power while charging (If any).

Do you have a recommendation for a charger that will charge successfully while the battery is under load?

 

[Island Jay]

Yes, the ProTech i. I have the 20 amp & 40 amp on sale for $72 & $90.
http://promariner.com/products/dry-...argers/protech-i-series-limited-availability/

What are you battery make/models? How many? 12v setup?

 

[Evildwarf]

Yes, the ProTech i. I have the 20 amp & 40 amp on sale for $72 & $90.
http://promariner.com/products/dry-...argers/protech-i-series-limited-availability/

What are you battery make/models? How many? 12v setup?

12 volt Dual battery setup on switch, one cranking and one accessory battery. Cranking battery is an interstate but I don't know the model. Accessory battery is an ancient Walmart brand that I will replace today.
I'm looking at getting a dual bank charger that will charge and allow for the bilge pump to be left on since I'm in a wet slip.

 

[Island Jay]

The 20 amp would be fine for $72, assuming both will be lead acid $80 or so batteries. It is a 3 bank charger, but will support 2 banks. You do need to provide your own AC & DC cables for the system.
Waterproof do have AC & DC cables, but again you run into the issue of drawing power while under load.

To take this conversation in a different direction, do you know the amp draw on your bilge pump? I may have an option with a waterproof charger as I have one that can support a few amps or two to power a device while charging. I can double check with the factory on Monday. Dry mount is 100% ideal fort drawing power while charging, but if your draw is an occasional bilge pump, we may have an easier option that will save you $$ in the long run.

Thank you
Jason

 

[Evildwarf]

The 20 amp would be fine for $72, assuming both will be lead acid $80 or so batteries. It is a 3 bank charger, but will support 2 banks. You do need to provide your own AC & DC cables for the system.
Waterproof do have AC & DC cables, but again you run into the issue of drawing power while under load.

To take this conversation in a different direction, do you know the amp draw on your bilge pump? I may have an option with a waterproof charger as I have one that can support a few amps or two to power a device while charging. I can double check with the factory on Monday. Dry mount is 100% ideal fort drawing power while charging, but if your draw is an occasional bilge pump, we may have an easier option that will save you $$ in the long run.

Thank you
Jason

Thanks Jason, I'll check the amp draw on the bilge pump later today when I head to the marina.

 

[Yamaha242lsdallas]

I went little above just using a trickle solar charger. I use a 100 watt solar charger that puts out around 6 amps. Folds up into a large suitcase type size and I keep in in the helm storage area. If we camp out for a few days or just beach for part of the day it's a quick 1 minute setup and keeps the house battery fully charged.

Even while storing the boat at the house I never need to worry about messing with extension cords, just a quick setup and it keeps my batteries topped off. I don't think I'd leave it in a place where someone could walk off with it though.