CPG1962

I am leaving on a trip and leaving my CTS-V at the airport for 3 weeks. I purchased a "Sunforce" brand battery tender which had an option of hooking to the battery or plugging into cigarette lighter.

Does hooking up to the cigarette lighter really to the trick? It would be a hell of alot easier as I would place the solar panel in front of the windowshade and run wore down.

Thanks and Happy Holidays.

timd38

Not all cars will let the power flow through the lighter. You can get a solar powered charger that plugs into the OBD port and those work great. In fact VW uses them to keep the batteries charged when their cars are parked at the port. You can find them on ebay because they come with the car and most people don't know what to do with them.

CPG1962

What is an OBD port?

timd38

It is the port under the dash that hooks up to the computer.

I have one of those charger that I use for my pickup and it works great.

CPG1962

Thanks - I'll drive by the dealership to ID.

timd38

Here is what it looks like.


http://cgi.ebay.com/VW-AUDI-SOLAR-PA...3%3A1|294%3A50

CPG1962

Thanks Much!!!!!

AORoads

have you tried the lighter socket when your key is out? if it's "hot"meaning it works, then you should be fine. The Corvette's does; that's where I plug my battery maintainer in at home.

If it's not hot, then you'll have to find the place that is.

timd38

Some cars have a diode (or something similar) that will only let the current flow one way, but I don't have list of cars.

AORoads

That's interesting. Makes sense. Glad the Vette doesn't have that.

johnodrake

I haven't tried it in the CTS, but connecting the tender to the C6 via the outlet in the console works fine.

CPG1962

I will try all the above. I think all GM's are "hot" even with the key out. Sure would make it easier.

C5pilot

Is there any possibility for a solar charger to over-charge a battery?

JohnDS

The ebay item states 18.5 Volts, which is way over the top, but maybe the low 5 watts rating wouldn't be a problem. Any EE's around here?

John

LloydP

18.5 volts and 5W (~3.7A) sounds high but it is unlikely to be a problem. Consider that those ratings are under ideal conditions.

In an airport situation, the cell will be behind glass cutting output by 10% or so. Also assuming the car is parked so that the sun rays hit the cell exactly perpendicular at 2 pm, not much electricity will be generated before about 10 am or after 4 pm. The integrated charge over each day should be well within the capability of the battery.

JohnDS

Wait, W = V * A
So 5 watts = 18.5 volts * 0.27 amps

It's 0.27 Amps, Right?

John

glass slipper

You're correct...it even says 275 mA (.275 A) in the picture of it on the ebay ad.

glass slipper

Here's a good link to read about solar panels:
http://www.amsolar.com/solarpanels.html
It's winter now and the OP is in FL meaning higher operating temps on the panel plus he's at sea level...according to the link, the 18.5V and 5W rating may be down to ~15 V and 3W. Not much chance of overcharging the battery at that rate, especially since those numbers will occur for only a few hours per day at peak sun.

CPG1962

This is the one I bought last week.

Up to 1.8Watts and 125mA (max)

http://astore.amazon.com/sunforce.so...ail/B0006JO0KG

I hope it puts out enough juice. Any EE's out there???

LloydP

Picky Picky Picky. Of course you are right and thanks for keeping me honest . Always re-read these before posting.

You know, at 270 ma under ideal conditions, I would think you would be lucky to get one Amp-Hour per day into the battery.

(and I re-read this one) Thanks, Lloyd