iPhone 3GS battery drains while on car charger

[bendrucker]

I've noticed that when I use the TomTom app on my iPhone while plugged into my Griffin Powerjolt SE, the battery will actually drain. It seems to drain more slowly than when the iPhone isn't plugged in at all, but nevertheless it drains. From 100%, my phone recently dropped to about 75% for an hour and a half car ride. If I just leave the phone in sleep or playing the iPod, the phone charges.

Is this something anyone else has observed? Is there a fix for this?

Also, I'm realizing now that I've always been plugging into the cigarette lighter since that's closest to the dash. Should I be plugging into the socket labeled 12V Power Port?

 

[bendrucker]

Anyone have any idea why this might be happening?

 

[Badfoot]

Couldn't find specs re the output capability, but it looks like it outputs around 1/2 amp max, and the iphone will be consuming more than this, hence the discharge. The output restriction is with the Griffin not the 12v or cigarette lighter source so swapping these won't make a difference.

 

[Gav2k]

I have both belkin and griffin incar chargers and both struggle to keep my iPhone charging whilst running navigon. I'm lucky if I break even once the trip is done.

Look for the range of ipad chargers avalible and try one of them. The extra oomph will charge your iPhone.

 

[bendrucker]

Thanks guys, that's what I figured. I have an iPad car charger so I'll try that.

 

[eelpout]

I just bought the new Griffin PowerJolt for iPad (and iPhone/iPod too) that puts out up to 2.1 amps. Most importantly, it seems to keep up with my 3G's needs while running a nav app, which is great.

But for some reason, the battery status indicator (under iOS 4 & jailbroken) does not actually show the charge increasing while it's plugged in. It sits on whatever percentage it was when when first plugged in and only registers the increase after one has unplugged it. Odd.

My cheapie 500 ma charger registers the increase OK. It's almost like the iPhone system can't deal with measuring the higher current. I'll have to check with Griffin to see if they've noticed this. They do say it's safe to use with any iDevice with a dock connector and not only the iPad.

Could be due to the jailbreak of course. Maybe SBSettings is at fault, but so far the Griffin is the only power source that behaves this way.

 

[bendrucker]

Thanks for the info. I haven't had a chance to try this out but I'll be curious to see if the higher amperage charger works correctly. The biggest problem I encounter with my black iPhones are that they get very hot in the summer in the sun. I had the phone shut off (even with the AC blasting) because it said it had overheated.

 

[rowejmc]

Just came back from a 5h trip today. Running copilot and suffered battery drain even though it was charging. Interested to know whether your higher amperage charger idea works?