How are those solar car battery chargers?

Muse

Lifer
Jul 11, 2001
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I can order them from Harbor Freight for $10 apiece, and I figure they may be worth it. I have two cars, one of which I only use maybe every 6 weeks, the other sometimes not for 2 weeks or more. I find that the batteries wear down just from running the cars' clock and whatever else might be a slow drain. I have a trickle charger I use from time to time, but it's a hassle to do that. The trickle charging solar units plug into the cigarette lighter. Of course, some days are sunny, some cloudy. I wonder if these things would do a good job of keeping my car batteries charged. My cars face north and I'm in Northern California, so I'd place them beneath the rear window. Anybody have experience with these?
 

loic2003

Diamond Member
Sep 14, 2003
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sounds like a gimmick to me, and you usually see these things on 'crappy gadget weeklsy' magazines, along with the rug anti-slip devices and spider catchers. I'd not bother. Pick up a fresh batter and maintain it.

Check your altinator if it keeps goign flat...
 

Muse

Lifer
Jul 11, 2001
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Originally posted by: loic2003
sounds like a gimmick to me, and you usually see these things on 'crappy gadget weeklsy' magazines, along with the rug anti-slip devices and spider catchers. I'd not bother. Pick up a fresh batter and maintain it.

Check your altinator if it keeps goign flat...

The thing is, if you only use your car every couple months, the battery won't remained charged even if it's new and your alternator's OK. My mechanic told me that he'd disconnect the battery in such a car, but it's a hassle to have to reconnect the battery every time I want to use the car, and it get's my hands dirty.

Really, I figure this probably works. I wonder how long the solar panels would last.
 

Eli

Super Moderator | Elite Member
Oct 9, 1999
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Originally posted by: loic2003
sounds like a gimmick to me, and you usually see these things on 'crappy gadget weeklsy' magazines, along with the rug anti-slip devices and spider catchers. I'd not bother. Pick up a fresh batter and maintain it.

Check your altinator if it keeps goign flat...
???

:confused:

Clearly, you didn't read the OP, or know nothing about which you speak. Or both.

:p

Yes, the solar chargers will work.

Whether it keeps your battery 100% full or not depends on how many Watt hours your battery is being drained and how many watt hours the panel will end up putting out.

I assume you're talking about the 1.5W ones. It should at least extend the time before the battery is noticably drained.

Try for one of the 2.5W ones.... Don't think Harbor Freight has them though. Check eBay, there are gobs of them on there.
 

Muse

Lifer
Jul 11, 2001
38,829
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Originally posted by: Eli
Originally posted by: loic2003
sounds like a gimmick to me, and you usually see these things on 'crappy gadget weeklsy' magazines, along with the rug anti-slip devices and spider catchers. I'd not bother. Pick up a fresh batter and maintain it.

Check your altinator if it keeps goign flat...
???

:confused:

Clearly, you didn't read the OP, or know nothing about which you speak. Or both.

:p

Yes, the solar chargers will work.

Whether it keeps your battery 100% full or not depends on how many Watt hours your battery is being drained and how many watt hours the panel will end up putting out.

I assume you're talking about the 1.5W ones. It should at least extend the time before the battery is noticably drained.

Try for one of the 2.5W ones.... Don't think Harbor Freight has them though. Check eBay, there are gobs of them on there.
Thanks! More watts is better. Didn't think of eBay, will check them out.

 

Sphexi

Diamond Member
Feb 22, 2005
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Yeah they do work, and depending on your usage of the car they work pretty well. Most newer cars are smart enough to stop most of the drains on the battery when they're not in use, down to something like 3W or so. So yeah, it won't keep your battery fully charged all of the time, but considering it would take literally weeks for 3W to drain a fully charged battery, it will almost double that time.
 
Oct 9, 1999
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yup it works.. for the motorcycle application..

not sure of the car one.. but if it generarates about 1.5w as others have said its enough to trickle.
 

Muse

Lifer
Jul 11, 2001
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Just realized this will only work if my cars' lighters work with the ignition off.
 

Muse

Lifer
Jul 11, 2001
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Originally posted by: Muse
Just realized this will only work if my cars' lighters work with the ignition off.

Guess it won't work for my '97 Mazda. Gotta turn on the ignition to use the cigarette lighter... screwed.
 

Eli

Super Moderator | Elite Member
Oct 9, 1999
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Originally posted by: Muse
Originally posted by: Muse
Just realized this will only work if my cars' lighters work with the ignition off.

Guess it won't work for my '97 Mazda. Gotta turn on the ignition to use the cigarette lighter... screwed.
Hardwire it.
 

Muse

Lifer
Jul 11, 2001
38,829
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Originally posted by: Eli
Originally posted by: Muse
Originally posted by: Muse
Just realized this will only work if my cars' lighters work with the ignition off.

Guess it won't work for my '97 Mazda. Gotta turn on the ignition to use the cigarette lighter... screwed.
Hardwire it.
Guess I could... Just run a hotwire right to the lighter. Is there any downside to doing that?