Power Drain question on car battery

The power drain is pretty low after the unit is fully charged. I have left mine in the car overnight in the same way, plugged in and powered - but turned off - with no ill effects. I usually pull the charger out just enough to get the light to go out before I leave the car, though.

One thing for you to check though is if the power LED on the cig charger is still lit when you get in the car the following morning. As a battery protection method, my car automatically shuts off most of the power after 30 minutes with the ignition off. For example, if I manually turn on the interior light, it will go off after 30 minutes if the ignition is off. I don't know if this applies to the cig lighter socket, though.

I often times leave my Motorola vehicle radio on over night (it has a constant power drain - I usually forget to turn it off after a FD call) and as long as I don't let the vehicle sit for days on end without driving it, the vehicle starts right up with no problems. So with a GPS that powers off when fully charged I would have to say you would be safe.

But usually, 15-20 minutes of driving (not just idling) will help recharge your battery as long as 1) your alternator isn't going bad 2) your water level in the cells is good or 3) your battery isn't near the 5 year mark or 4) the battery terminals are kept clean, etc.

My BMW x3 cigarette lighter socket is always "hot" but my wife's Grand Cherokee goes off when the ignition is off. Each car / company seems to have their own approach.

Cheers

I have two, one is switched and the other isn't.

Either way - switched or not - I don't think you'd have to worry about a GPS draining your car battery even if you left it turned on overnight. The capacity of a car battery (which I have read is typically between 50 and 60 amp hours, at 12 volts) is roughly 65 times that of the C340's internal battery (3.7 volts, 2.4 amp hours - at least, that's what the replacement ones for sale on Ebay are rated).

Both of my vehicles have switched recepticles, so the nüvi and Sirius both turn on and off automatically. An unswitched main recepticle would be a real bummer, though having a spare that stays on would be nice for charging phones and such.

Some vehicles (GM, I think) you can easily make them unswitched or switched. Our 2-way radio guy told me that, he checked my Nissan Altima, but said they didn't have that feature and it would take a re-wire job. All mine go off with the ignition. He said that with the computer chips in cars nowadays, it can be a pain to re-wire some vehicles.

install a separate 12 recepticle and wire it to a fuse that turns of with the ignition.