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iPhone will not charge when GPS is in use - it's a huge battery drain!

Rybold

Rybold

macrumors 6502a
Original poster
Jun 23, 2008
960
0
California, USA
Yesterday, I charged my iPhone3G from "10%" until completely full using my car charger. No problems at all. Today, I was on a "mini road trip," and I was using my GPS, yet even though I had it plugged in, the battery kept getting lower and lower, and then the "20%" and then "10%" warnings popped up. Upon seeing 10%, I looked more closely, and noticed that instead of the usual "lightning bolt" in the battery indicator, it had an image of the power plug but the battery was at 10% and not full. I disconnected my phone and then reconnected it several times. Nothing. Then I exited the GPS application and turned "location services" to off, and WHAALAA!!!, my phone began charging. About 30min later, I turned Google Maps back on but kept the location/GPS off. My phone kept charging. As soon as I clicked on the bottom left corner for the GPS and it asked me if it was "OK" and I tapped "OK," I then noticed the battery stop charging. I'm guessing that the GPS is such a battery drain, that trying to charge at the same time could harm the battery, and so the iPhone is programmed to not charge when the GPS and 3G are both running.

Anyone else have a similar experience?
 
I'm guessing your car charger doesn't deliver the full 4.75-5.25v 500mA required for a USB2 high bus powered device. If you've got a multimeter it'd be interesting to test it and see.
 
alFR said:
I'm guessing your car charger doesn't deliver the full 4.75-5.25v 500mA required for a USB2 high bus powered device. If you've got a multimeter it'd be interesting to test it and see.
Click to expand...
Wouldn't it be great if the iPhone 3G only required 500mA? It actually needs 1000. ;)

For the OP, this is a known problem. In certain situations, the iPhone 3G uses more power than a charger can provide: https://forums.macrumors.com/threads/552317/
 
mavis said:
Wouldn't it be great if the iPhone 3G only required 500mA? It actually needs 1000. ;)
Click to expand...

What, you mean 1A? ;)

Interesting if true - the iPhone power adapter is rated at 5v 1A, yes (the original iPhone one is the same) but the max power spec for USB2 is supposedly 500mA. If it does need 1A, how come it'll charge from a standard USB2 port then?
 
Same here

I have noticed that the phone draws more power than it can take from the charger- both in the car and plugged into the wall.

I have noticed it with GPS and with Netshare.

When plugged in, you get longer, it slows down the drain, but it will not keep your phone charged.
 
Wirelessly posted (iPhone 3G (16GB, 2.0.2 JB'd): Mozilla/5.0 (iPhone; U; CPU iPhone OS 2_0_2 like Mac OS X; en-us) AppleWebKit/525.18.1 (KHTML, like Gecko) Version/3.1.1 Mobile/5C1 Safari/525.20)

alFR said:
mavis said:
Wouldn't it be great if the iPhone 3G only required 500mA? It actually needs 1000. ;)
Click to expand...

What, you mean 1A? ;)

Interesting if true - the iPhone power adapter is rated at 5v 1A, yes (the original iPhone one is the same) but the max power spec for USB2 is supposedly 500mA. If it does need 1A, how come it'll charge from a standard USB2 port then?
Click to expand...

Yeah, that's what I mean. :)

As for your question, I don't know - I use a powered USB hub, which I had assumed was the reason my iPhone 3G was charging while plugged in. But I actually had trouble with a 3600mAh external battery pack rated at 800mA output (@5v) - it charged my iPod touch just fine, but not my iPhone. I had to buy the UPB10 (rated at either 1.5 or 2A, IIRC) to get it to charge ... The iPhone 3G definitely has more demanding charging requirements than its predecessor.
 
Wirelessly posted (Mozilla/5.0 (iPhone; U; CPU iPhone OS 2_0_2 like Mac OS X; en-us) AppleWebKit/525.18.1 (KHTML, like Gecko) Version/3.1.1 Mobile/5C1 Safari/525.20)

I think you mean "voilà!"
 
I have this problem with my car charger as well. Although I think the problem is that the GPS is draining the power faster than your car charger can charge, hence why it probably gets very hot while charging and using GPS at the same time.
 
Bye Bye Baby said:
I have noticed that the phone draws more power than it can take from the charger- both in the car and plugged into the wall.
Click to expand...

When I have my phone plugged into an AC wall socket, it charges VERY FAST! Even when I'm using it, it still charges up. (and obviously, I have the GPS turned off when I'm charging it at my house or office) I turn the "location services" to OFF in the settings unless I'm actually using the GPS. This also makes using the camera faster; if location services are set to Off, it will Not ask you the annoying question of whether it is okay if the camera uses the GPS.

animenick65 said:
I have this problem with my car charger as well. Although I think the problem is that the GPS is draining the power faster than your car charger can charge, hence why it probably gets very hot while charging and using GPS at the same time.
Click to expand...

The back of my phone did get very warm (not in the sun). In fact, I even removed my rubber InCase so that the phone could dissipate heat more quickly. That's the only drawback to cases; they impede thermal cooling, and when using the GPS or constant 3G, the battery gets hot. Otherwise, I'm very happy with the protective case on my phone.

Conclusion: GPS on the iPhone is not sustainable for extended periods of time.
.
.
.
 
I've had this problem, but I put it down to the phone overheating and shutting off the charging circuits. It will happily charge if you only listen to music, but when you use GPS for a while with the screen on, it gets very hot and refuses to charge to prevent damaging the battery (hence why the 'full' indicator shows)
 
Mine does charge while using GPS, but I have mine connect to the computer via the USB cable. Maybe you car adapter doesn't have enought mAh to charge the iphone.

I'm inside a building and the GPS use more power to fix the position and still is charging.

phone003mediumkg0.jpg
 
ajthomason said:
I've had this problem, but I put it down to the phone overheating and shutting off the charging circuits. It will happily charge if you only listen to music, but when you use GPS for a while with the screen on, it gets very hot and refuses to charge to prevent damaging the battery (hence why the 'full' indicator shows)
Click to expand...

cdesigns said:
Mine does charge while using GPS, but I have mine connect to the computer via the USB cable. Maybe you car adapter doesn't have enought mAh to charge the iphone.
Click to expand...

Hmmmm. Interesting. I'll have to do some experimenting then and see if it's overheating instead of the GPS that is causing the charging to shut down. Thank you for the info.
(I'm going to turn my GPS on next time I am in my car, and observe whether the charging shuts down immediately or whether the phone needs to heat up for the charging to shut down. Then I'll do a separate experiment with the GPS turned off and I'll just keep loading 3G websites over and over and get it to heat up, and then see if the charging automatically turns off.)

AC charger: "1Amp" ____ DC car charger: "500mAh"
 
Rybold said:
(I'm going to turn my GPS on next time I am in my car, and observe whether the charging shuts down immediately or whether the phone needs to heat up for the charging to shut down. Then I'll do a separate experiment with the GPS turned off and I'll just keep loading 3G websites over and over and get it to heat up, and then see if the charging automatically turns off.)
Click to expand...

Please don't do it while driving ;)
 
animenick65 said:
I have this problem with my car charger as well. Although I think the problem is that the GPS is draining the power faster than your car charger can charge, hence why it probably gets very hot while charging and using GPS at the same time.
Click to expand...

the iphone automatically stops charging once it hits a certain temp as a safety feature...

has anyone tried seeing if when cooled (yes its a hassle) if it will charge when running gps/3g?
 
NT1440 said:
the iphone automatically stops charging once it hits a certain temp as a safety feature...

has anyone tried seeing if when cooled (yes its a hassle) if it will charge when running gps/3g?
Click to expand...

Try putting the phone in the direct path of the air conditioner vent. That may cool it down.
 
Both yesterday and today, I conducted both experiments.
Experiment one: I used the GPS when the phone was not hot, and I plugged the phone in and it charged. As soon as the phone got too hot (about 15min later), the charging shut off. I unplugged the charger and plugged it back in and it would not charge. I turned my phone off and let it cool down. I used GPS while charging and it worked fine until it again got too hot.
Experiment two: While using my phone with location services turned Off, I noticed my phone was getting hot. I plugged it into my car charger (I was sitting in a parking lot) and started downloading internet pages back to back on 3G, and within 5 minutes my phone got really hot and the charging shut off. I let it cool down and repeated. Same result.

Conclusion: GPS is not the cause; overheating is the cause of the phone automatically disabling battery charging. In other words, when the phone has reached a hot enough temperature, it will not allow you to charge it. In the Future, whenever charging my phone in my car and using GPS or a lot of 3G at the same time, I will be sure to remove the rubber case from my iPhone3G to allow more efficient cooling.
 
(knock on wood) I've never experienced anything like this before with my iphone. I'm not sure what to say here. you guys must have bad phones or something?
 
Rybold said:
Conclusion: GPS is not the cause; overheating is the cause of the phone automatically disabling battery charging. In other words, when the phone has reached a hot enough temperature, it will not allow you to charge it. In the Future, whenever charging my phone in my car and using GPS or a lot of 3G at the same time, I will be sure to remove the rubber case from my iPhone3G to allow more efficient cooling.
Click to expand...

My prediction was right it seems - good to have it confirmed. At first, I thought it was my charger then noticed it would happily charge after I just locked it at left it for a while.
 
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