Driving Less? Let the sun maintain your car battery
The other day we had a post about the need to continue doing some basic maintenance on your car even if you are driving less in this age of higher fuel prices. One of the items we mentioned was caring for your battery. If you drive your car infrequently as I do (I drive a lot of loaner vehicles from manufacturers for review purposes) you may find that your battery eventually dies. Just as all the electronic gear in your house draws juice to light up all those LEDs, so to does your car for alarm systems, clocks etc. Even with nothing drawing power, a battery will eventually self discharge. I use an inexpensive trickle charger that slowly charges my battery and automatically shuts off when full charge is reached and then re-starts when the voltage gets below a certain level. Mine is a plug-in unit because my car is in a garage. If you park your car outdoors, though, you might want consider a solar charger. The1.8W unit pictured above is available online for under $25 and measures 6.5 x 1.25 x 18 inches so you can stick it on your dashboard and plug it into an accessory socket. If you are going to leave it sitting for extended times you should also go for a charge controller that monitors your battery to prevent over-charging. Just as with a hybrid battery, overcharging your starter battery will damage it. You can find various examples of these devices by using your favorite search engine to look for "solar car battery trickle charger" and you shouldn't need to spend more than $50. It's cheaper than a new battery and less hassle.
Reader Comments (Page 1 of 1)
Paul Allen 10:17AM (10/20/2008)
Uhhh, you won't have to worry about overcharging your battery with that tiny little solar panel, the 1.8 watt output means it only puts out 1/8 amp (1.8 watts divided by 14 volts), and I'm sure that's on a very sunny day. You'd need eight of them to equal the output of a little plug-in trickle charger.
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why not the LS2LS7? 10:58AM (10/20/2008)
I was going to say what Paul Allen there said.
You could force-feed 1.8W into a car battery forever and it wouldn't damage it. The energy goes into the battery and since the battery has no use for it, it turns into heat. But 1.8W of power across a mass the size (and density) of a car battery doesn't amount to any noticeable temp rise.
Additionally, you charge lead-acid batteries by float charging them, so as the battery becomes full, the charge rate reduces, where by the time you hit fully charged, the charge rate is very low (even less than 1.8W) and so everything works great.
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Bill 12:16PM (10/20/2008)
I've been using on of these tiny panels for the last year to maintain the battery on my spare car. It works great! I keep it on the dash board usually, at least after I forgot it was suctioned cup attached to the rear window and lowered it, shearing the plastic suction cups...
It will easily keep up with the current drain from on board computers and clocks. I had a "small" electrical short at first (~3-4 amps) and this tiny unit couldn't keep up with that current demand though.
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Dan 8:13PM (10/20/2008)
This is a good idea but the problem is that if the ignition is not at "ON" on my car, there's no electricity in the accessory socket. Even if I plug a solar panel in the accessory socket the battery will drain. If want the solar panel to recharge the battery I have to let the ignition to "ON" (it makes no sense).
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Chuckdaddy 9:44PM (10/21/2008)
VW/Audi Group has been using these or similar on all their
cars delivered to dealers. Also some cars do have live
sockets, I know mine does, I can charge my cell phone with the ignition off.
moyoi 10:09AM (10/21/2008)
and so you get owned for driving an import, schucks!