Will a 1.5 watt solar charger damage a truck battery?

[Johnny Lightning]

Ok guys I'm a little gun shy here. I ruined a brand new battery a few years ago (actually about 3 decades ago) by hooking it up to a 2 amp battery charger over the winter. I now have a truck I'm not going to be driving for a while and I'd like to put a cheap Harbor Freight battery maintainer on it. The maintainer is only 1.5 watts or about .125 amps so I think I'm probably pretty safe, but folks around here know lots more about this stuff than I do. Any educated opinions? I don't need another $100 lesson in battery maintenance.

 

[Deleted member 783]

I've had a 3 watt charger plugged into the cigarette lighter on my 84 chevy for about 3 years continuously, without issue. Gas or diesel truck?

Edit: I was replying to the wattage in your title.

 

[Johnny Lightning]

Gas truck Oops my bad it was only a 1.5 watt charger so I'm probably good. I just don't want to ruin a battery by letting it discharge and freeze.

 

[TheDroidsYouAreLookingFor]

1.5 watt is great for battery storage in a truck. Should make the battery happy come spring. Make sure its charged before you leave it there.

 

[Johnny Lightning]

Well I just drove it 600 miles from Virginia to Michigan so if it ain't charged now it ain't gonna get charged. I actually found a solar maintainer at Home Depot that is a little smaller but it's weather proof so I think I'm going with that one because I have another mission for it in a few months. Thanks guys or gals.

 

[MrNatural22]

Something to think about, those small PV battery maintainers will perform poorly if you, as most do, put them on your vehicles dash. Automotive windshields and glass have UV protection and may block the PVs output. Simple way to demonstrate this is if your eyeglasses are photo-gray they will not darken very well inside your vehicle, even in direct sunlight thru the windshield. Hold them outside and they will darken quickly.
Those maintainers need to be outside in the sun on the roof or other site to work. ?

 

[TheDroidsYouAreLookingFor]

Sounds good. My battery maintainer for my old flatbottom was a 6 watt 1 foot square panel. It stayed on top of the cover at the edge of the car port where it got maybe 4 hours of sun a day in the winter. Always perfect start on one of those giant marine deep cycle/ start batteries from wal-mart. I have seen to many people show up to the marina and then wonder why their boat wont start. then they sit on the ramp taking up space as they go buy a battery from the marina at double the price.

 

[MrNatural22]

Oh yeah those marina prices ? they learn fast. (Marina gas is more expensive than marina beer) I have two non automotive use LA batteries (genny and D cycle Wally World) I keep on battery tenders both over 2 years old and still strong.

 

[DThames]

If it plugs into your dash socket, make sure it is hot even with the power off or the battery will never see the charger. Also, check it once in a while to make sure you are getting the desired results. I have not had good success in this area. Some cars/trucks have loads on the battery even when nothing is on. So your charger would need to be greater than these hidden loads.

 

[Johnny Lightning]

Yep the "lighter" socket is hot when the key is off and yes there are some loads but not too much. The problem with putting the panel outside is how do you get the wire inside without going through the window or door which would create a path for rain/snow. I think I'll just put it in the windshield, it points south so it should be OK. I guess we'll find out.

 

[DThames]

Yep the "lighter" socket is hot when the key is off and yes there are some loads but not too much. The problem with putting the panel outside is how do you get the wire inside without going through the window or door which would create a path for rain/snow. I think I'll just put it in the windshield, it points south so it should be OK. I guess we'll find out.

Yes, wire routing is a problem. I had considered making a pigtail that hung down under the front/grill somewhere, so you could plug it up from the outside, but I never got around to it. I drive my old Jeep often enough that it stays up unless I let it set more than a few weeks. So I never got back to messing with it. If the window tint is too much, just get a larger or second panel

 

[Johnny Lightning]

Ya I don't want to get too involved, this is a short term solution until spring when I should start driving the truck full time and sell my old one. I just don't want to get my new-to-me salt free truck exposed to salt and start the rusting process. I guess the worst thing it could cost me is $150 battery.

 

[TheDroidsYouAreLookingFor]

If you want to run something through the door run it through the bottom, make a drip loop then put the panel wherever you want. This is how wire is run into buildings without water following the path. Your truck isnt as sealed as you think it is anyways or the doors would bounce back open on a cushion of air. The dash should work fine though and you dont need to run it outside.

 

[TheDroidsYouAreLookingFor]

Or connect it to the battery thats already outside under the hood, Or bring the battery with you

 

[MrNatural22]

Because of the high price of diesel I don’t use my truck unless I need the grunt or hauling material so it sits sometimes for a month.
If you check power with the panel on the dash or outside you’ll see a big difference because of the UV protection.
I have had mine run out by just closing the door on the very small wire to the panel. No pinching problems on such a small wire. It’s been thru many rain downpours here without any leaks. Many vehicles have more than one dash lighter socket with one that has constant power key on or off. If not just connect direct To your battery as The droids just said. ?

 

[Johnny Lightning]

Well guys and gals the 4 month test gives the solar maintainer a big thumbs up. I was out of town working, this came up kinda sudden and I had to leave one of my trucks at the airport for 3 weeks. Got home battery DEAD, wouldn't even light up the dash. The truck at home with the 1.5 watt solar maintainer started right up. Had to go back to the airport 3 days later to go back to work. Took the maintainer with me. Left it for another 3 weeks, started right up again. So yep, I'm a fanboy. Nature Power Rocks. And it's supposedly waterproof too but I haven't tested that.

 

[JoeHam]

Glad to hear it.

Remember that your old charger that fried the battery was 24 watts. So 1.5 w seems to be the sweet spot for your application.

 

[TheDroidsYouAreLookingFor]

Did the same thing with a riding lawn mower... end of season just plugged in and walked away... spring time... turned the key that was still in it and after about 20 seconds of cranking its ALIVE... then just brush off all the oak leaves and air up tires. Cheapest battery insurance ever for lead acid batteries.