Perivision's Blog : Written first, edited later.

August 3, 2008

iPhone 3G will not charge with my car charger

Filed under: iphone — perivision @ 3:19 am
Tags: , , ,

This is something I did not even think to check till driving into iphonebarcamp today. The iphone 3G would not charge on my car charger. FTW? Well, seems like it’s a common problem and here is the reason, the pin that normally accepts power for firewire is no longer connected. Here is the quote from Macworld..

..iPhone 3G doesn’t support charging “via FireWire.” The thing is, there are lots of devices out there that don’t actually have a FireWire port, but are technically FireWire chargers because they’re sending power on the dock-connector pins that were used for power by the FireWire interface. There are a lot of reasons for this, chief among them the fact that the FireWire spec allows as much a 18 volts, while USB is a 5-volt connection. Since cars provide 12 volts of power, many if not most car-chargers used the FireWire method to send power.

Worse, the firewire line is spec’ed to take more power, thus shorted recharge times. The USB pin is only 500mA. On the other side of the coin, slower recharge is better for the battery.

Great. So now what? Well, we have a few options here. We can rewires this thing ourselves, but if you bought a cheap recharger, I can tell you right now its not worth the trouble.

The second option is to buy an adaptor. Here is a WAY overpriced one from Ridax.

the third and best option, buy a new adaptor. Here is one from Kensington, and another from Griffin. If you do not mind taking your chord or have an extra chord, you could try these guys who have an ebay story.

###### (Update) ##########

Found this charger on Amazon. Got a poor review, but for the price, I’m going to try it anyway. I’ll update here again once I get it and test it.

Here is a link to a blog with more information.

For those who want the geek details, go here

and here

Now the question that popped into my mind is… What about all those car manufacturers who made doc form factors for the ipod/iphone? If they used the firewire pin instead of the USB pin, then your car will not charge your iphone. Given that the 3G battery life is more like a 1/2 life, this can be an issue. Worse, some people will connect their new 3G’s into the car and not see the warning that it’s not charging.

The car companies are going to complain. BUT, will Apple listen? Apple vs. the car companies.. I will be watching this.

Another group of unhappy campers? Peoples who form fitting ipod/iphone players that had iphone adapters. If the manufacture did not follow the correct power pin placement, you will have to either play on battery or use a cable. Neither option is very good. I have an ipod/iphone desk clock radio at home. Should be interesting to see if it works. (UPDATE: it does.) 🙂

BTW, my car radio does not have an Aux in, but I still wanted to use it for hands free and playing my mp3’s from the iphone. Solution? Override the CD changer! Get an adaptor cable, try here and here.

Next, go to your apple store and buy the monster mic cable or something like it.

There you go. You are now hands free. …. No, I do not like bluetooth, and FM transmitters? Com’on.


  1. […] The 3G does not use the firewire pin for power anymore. Many older (cheaper) power adapters used that pin because it allowed more power, thus faster charge. More here and here. […]

    Pingback by Should I upgrade to the iPhone 3G - list of questions and answers | As Seen Through PeriVisioN — January 12, 2009 @ 10:21 pm | Reply

  2. I returned it shortly thereafter. The biggest annoyance: an imperfect bluetooth connection and oddly responsive keyboard

    Comment by takayo — December 16, 2010 @ 1:30 am | Reply

  3. What a bummer when you buy an iphone that won’t charge on your car charger. I will be careful when I buy an iphone that it will charge on my car charger, and too bad that people would probaby not be able to play their iphone/ipod clock radio because of the incorrect pin placement. This can cause some problem.

    Comment by Elena — March 17, 2011 @ 3:26 pm | Reply

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