Solar powered battery maintainers

[Aldaris]

Will a 1.5 watt solar powered battery charger maintain the charge on a car battery, or is it generally a waste of time and effort? The car has a generally healthy electrical system but we want to make sure that it's absolutely reliable and starts even after sitting for a while. Here's a link to the charger in question.
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=44768

 

[Quest]

1.5Watter solar panel only gives no more than 130mA, not even come close to that to a wallwart "maintainer".

It's a waste of mullah if I were you, I would consider a 15Watter and then get a solar panel charger controller module to go with it.

 

[mrsilv04]

One of the Ford Tauruses in the fleet where Dad works has a slow drain on the battery that no one (even the dealer) could find. About twice a month, it wouldn't start.

So, they screwed one of these solar battery chargers to the dash on the passenger side, and plugged it into the cigarette lighter.

Problem solved.

 

[johnd]

I actually have some experience in this area. I have a solar powered Ham Radio station that uses two Optima Yellow top batteries. When everything is off, daytime maintenance current runs about an amp in my monitoring equipment so i'd want something that was at least .5 amp for a single 12v battery. .5I x12E=6W watts or there abouts. Remember, the amount this will be charging every day is less than 12 hours of a 24 hour day, depending on the season

 

[brianl703]

I think so, the VW solar panels they used to keep the batteries in their cars charged as they are being stored put out about 170mA.

A 15-watt panel is overkill.

The standby current drain on your car is most likely less than 25mA. If you're putting 130mA into it then you're offsetting about 4 hours of draw for every hour of sunlight it gets. If you get 6 hours of sunlight, it's offset the draw for the whole 24 hour day.

So to answer your question, yes, it will work.