GPS Application while plugged in to Car Charger

Yes I have had this happen as well. It must be a bug.

The Griffin outputs 500 mA, compared to 1000 mA from the AC charger. Not quite enough for heavy activity like GPS and 3G/EDGE plus the display.

No problems charging the phone while driving and using GPS.

I have done this before for a few hours when i was a passenger because of massive holiday traffic and it worked very well. Started with a full charge, plugged in (phone started charging and showed the charge symbol) and finished 3h later with a full charge but a very warm phone.

wlirio wrote:
I had a friend of mine who also has he iPhone 3G with the same car charger and his actually charged while driving home which is oposite what mine does

Well FWIW I personally had a few instances where the battery icon would be showing the charging indicator, and then eventually the fully-charged indicator (plug symbol)--all while Google Maps/GPS was active and the PowerJolt connected to my iPhone...only to discover that, upon disconnecting the charger from my phone, the battery indicator was displaying that the battery was down to 10% capacity; another time, the display was still showing full after charger disconnect but shortly after I had to reboot my phone (for a different reason), the display then showed nowhere near a full capacity.

I think there have been more than a few posts regarding how the iPhone battery indicator would sometimes erroneously show a full capacity even though iPhone usage should have indicated otherwise.

Another theory is that the iPhone has a thermal overload circuit protector that shuts off its charging circuit if/when the phone becomes too warm (probably due in part to the GPS working hard...at least that's how it seems to be in my case--the phone doesn't get really warm at all when used in any other manner and while connected to a car charger).

I drove from Corpus to Austin and used the gps while being charged and when I came home the battery was dead....plus my battery life is about 4 hours with 3g and wifi enabled and bluetooth disabled

I also had a weird battery drainage issue once when syncing the iPhone on my Mac.

I plugged it in and it was doing it's backup. The backup was taking over an hour and this was before the recent update that fixed the long backups. Well, the backup was going on for over an hour when I kept noticing the battery indicator showing in the red. After a while longer, the iPhone shut off in the middle of the backup. It ran out of battery power while connected to my Mac Pro.

That has never happened since but it seems like it is the same problem.

I have done this before for a few hours when i was a passenger because of massive holiday traffic and it worked very well.

Perhaps, because of the massive traffic, you were not having to pull down map sections over the air as often as other, speedier, users had to.

The zoom level would also affect the need to get more map sections.

After talking to a buddy of mine who had the same issue (he had 3G/BT/GPS/iPod running all at the same time); however, when he tried it again but this time not have iPod playing in the background...there was no battery drainage issue--i.e., his phone was able to at least maintain a steady battery capacity level, if not become fully charged. I tried this myself, letting Maps run in the foreground continuously for a little over an hour, BT and 3G on/enabled, but no iPod playing in the background. At the end of the drive, I disconnected the charger and then rebooted my phone to eliminate the possibility of an erroneous battery level reading...battery level did not show a decrease from what it was prior to the drive.

Have you tried not using WiFi, that can really kill the batter. If you're in a car you don't need WiFi on, it will be continuously searching for as signal if you leave it on.

I've used the GPS as you are and the screen has never turned off on me, my auto lock is set to 5 min.