Solar car chargers?

[Grant Lamontagne]

Well, it's happened yet again... my wife has not driven her car for so long that the battery is dead.  I'm looking at three different models, a 1.8W, a 5W and a 15W model.  I usually am a "more power" kind of guy, but I'm not so good with electricity, so I thought I'd check to see how much I actually need to do the job.

Or, does anyone else have any other suggestions?

Def

[Mike, Lord of the Spammers!]

You've got two big dog's, buy her a Sled

[zepla]

I'm not an electrician either but as far as I know that Watts are not that mportant in a battery charging situation but the Amps are. What is the amp output on those things? Someone told me that for example: you have a 80 amp/hour battery and a 10 amp charger than it would take 8 hours to charge. Just divide the battery amps with the charger amps.

But if this is not right please let someone correct me, but the guy who told me this was pretty sure.

[Grant Lamontagne]

I don't much care if the battery is fully charged or not... I just need enough to make sure the thing starts when it has to.

Def

[Anthony]

Is this a kind of thing that "trickles" energy into a battery through a solar panel to make sure it doesn't drain like this pic?



Or is this something you connect to a drained battery to get it back at full charge?

I don't know, maybe it can bring a batt to full charge to

[MultiMat]

Is this a kind of thing that "trickles" energy into a battery through a solar panel to make sure it doesn't drain like this pic?

(Image removed from quote.)

Or is this something you connect to a drained battery to get it back at full charge?

I don't know, maybe it can bring a batt to full charge to

I got a $15 one of these from a discount store . My 225 Chrysler Valiant has been off the road for 18mnths & it has always had just enough charge to start(it has been 3mnths since I last tried )

[Grant Lamontagne]

That's exactly the doodad I was thinking of.

Def

[WhichDawg]

I wouldn't get the 15W, you could fry out your battery!
here are some reviews comments about it (read the responses down the page);
 http://www.gadgetreview.com/2006/07/solar-panel-car-battery-charger.html

[jzmtl]

Since they are intended for car batteries I would imagine they have 12v output, so that gives you 0.15, 0.42 and 1.25 amps at maximum sunlight. I'm 99% sure car battery can take 1 amp trickle charge indefinately, so the panel will only charge it a couple of hours per day and most likely will be operated at lower amperage due to not enough light, then there's constant power consumption from CPU, stereo etc., I think the 15W one is a safe bet.

Although if you pull the IOD relay you can get away with a smaller one, but unless you are storing the car for a long time I wouldn't do that.

[hawkchucker]

You could also look into those little things theat just plug into the Lighter, and jusp start the car. They are really small now and you can get them from wallyworld around 20 bucks. They do fit in the glove box.

[Grant Lamontagne]

My father in law has one of those things that you plug in- the problem is that it also has to be charged...   I like the idea of a solar panel since it continually recharges the juice (theoretically) that the clock on the stereo and the CPU will drain.

Plus, the temperature has been all over the place lately.  Some days it's nice enough to drop the top on my Jeep (saw a guy riding a motorbike on Christmas day) all the way down to -15C.  I know that doesn't help the battery much when it's just sitting.

Def

[WhichDawg]

You could also look into those little things theat just plug into the Lighter, and jusp start the car. They are really small now and you can get them from wallyworld around 20 bucks. They do fit in the glove box.

and remember many cars today, the cigarette lighter turns off when the car is off,
something to check out before hand with each vehicle.

[Grant Lamontagne]

My Jeep does that... bugs the crap out of me since I can't charge my phone when I'm at work!

Def

[WhichDawg]

My Jeep does that... bugs the crap out of me since I can't charge my phone when I'm at work!

Def

in that link I posted one guy talked about it, their are ways around it.

[jzmtl]

It's probably easier if you just hardwire the panel to the battery. Or get one of those Audis that have sunroof as solar panel.

[Grant Lamontagne]

If I could afford the Audi, I wouldn't need the wife...

Def

[Dtrain]

I think that the Solars are more of a maintainer than a charger. As long as you start with a hot battery and have plenty of sun light you will be good to go. Ampos are the key. previous post was dead on about the formula. Something that could also help is to put a switch on the Pos cable that you can completely disconect the battery when sitting for extended periods.

Dtrain

[SnWnMe]

I disconnect the battery before I deploy. 6 months later it's still GTG