Solar Panel

I have a question regarding the little solar panel on the back. I know it only charges the 12 volt battery. I am wondering, if I am driving on a sunny day here in southern California, and I plug in my cell phone, it will charge the phone without lowering my range or draining the battery?

Expecting the car in June, hating the wait and leaning what I can in the meantime...

mzwibel said:

I have a question regarding the little solar panel on the back. I know it only charges the 12 volt battery. I am wondering, if I am driving on a sunny day here in southern California, and I plug in my cell phone, it will charge the phone without lowering my range or draining the battery?

Expecting the car in June, hating the wait and leaning what I can in the meantime...

Click to expand...

As long as the current coming from the solar panel is greater than what is coming from the 12 volt battery, yes. Under most circumstances though, I doubt that the solar panel will be able to generate enough current to out-weigh the 12 volt accessories being used at a given time.

I know your question was probably more out of curiosity than concern, but think of it this way: An iPhone 4 has a 1,420mAh battery pack rated at 3.7v, that works out to a mere 5.25Wh for a full charge. Compared against the 24KWh battery pack, that's less than one quarter of one tenth of a percent.

EDIT: updated with actual numbers

Simply put, the solar panel is simply and purely a gimmick of little or no value. I measure the output from it and in full sun it outputs less than an amp, about 9 watts.

mzwibel said:

I have a question regarding the little solar panel on the back.

Click to expand...

The solar panel is nothing but decoration. But the draw to charge your phone is too small to notice. So in the end it's a wash. Don't worry about the phone, but don't expect the panel to do anything.

9w would seem to be plenty to float the 12v battery as it is designed to do. So I would not call it worthless.
Anyway charge away on the cell. It is just too small to even care the small fraction of a mile you might lose.

You've got up to 24,000 watts of power in the car's main battery (which also charges the 12 volt battery)... The roughly 50 watts per day you'll get out of the solar panel under ideal conditions parked outdoors may not be worthless but it certainly is damn close to it in the overall scheme of things. 2/3 of an amp is one (small) light bulb and less than many smart cell phone chargers draw. I would have preferred that the money be put somewhere else where it would have done more good.

smkettner said:

9w would seem to be plenty to float the 12v battery as it is designed to do. So I would not call it worthless.
Anyway charge away on the cell. It is just too small to even care the small fraction of a mile you might lose.

Click to expand...

How many people are going to park their Leaf outdoors in the sun for extended periods? When the car is on, the big battery keeps the little battery charged. And if you are going to leave the car off long enough the the 12-v battery to drain you'd really want to have it under cover. I don't even like to leave a conventional car parked in the elements for long periods. I pay extra to park in the covered garage at the airport, and at home I leave my car in the garage. And if I MUST park out of doors for an extended period, I put a tarp over it.

Maybe if you park at work out of doors and leave the radio on, the solar panel would help, or if you left your lights on the panel might delay the death of the 12-v battery. But really, for all practical purposes, the thing is decoration. At best, it's a conversation starter to educate people about PVs, which installed on the roof of your home are a really good thing.

That little solar panel probably didn't cost a whole lot, and it might actually help to extend the life of the 12 V battery a tad. Lead acid batteries seem to hold up best when constantly topped off. Still, I agree that it's there more for the "cool factor" than for any practical reason.

We don't have a garage or carport, and we don't cover our cars. But then again, we live above most of the smog and marine layers, and our driveway is in shade the majority of the time. So I don't think our car exteriors fare any worse than someone whose car is garaged every night and parked in full sun in an office parking lot every day.