iPhone 3GS - "Charging is not supported with this accessory."

[greenleaf]

Just put together my MintyBoost kit but unfortunately it doesn't seem to work with either mine or my wife's iPhone 3GS. The "Charging is not supported with this accessory" window pops up when I plug it in.

Multimeter shows 4.98V and 1.95V when I test the USB pins. Any ideas where things went wrong? I checked the soldering and everything looks ok...

[scott-42]

I don't know what the problem is but I'm curious what version of iOS are you running on the two phones?
I have two 3GS phones in front of me and it works on both and they have iOS 3.1.3 and 4.3.3.

Are you using an official Apple cable or a third party?

Also, can you post pictures of both the front and back of your minty boost?

[adafruit_support_bill]

The voltages at the USB connector sound right. Try another USB cable. Some have too much internal resistance which results in a lower voltage at the phone.

[greenleaf]

I'm running jailbroken 4.2.1 firmware, and tried two official apple-brand charging cables. I also tried freshly charged eneloop batteries, and brand new Duracells. I'll try to snap some photos of the PCB later today or tomorrow.

[greenleaf]

Ok, so this is weird, on a whim I just plugged it in again this morning and didn't get the popup warning. The only difference is that the phone is completely topped off from the wall charger this time. The missus' phone, however, is only about halfway charged and still shows the error message.

I'll try it a few more times during the day to see if the message comes back as the phone discharges...

[adafruit_support_bill]

When you see the error again, measure the output and data pin voltages again while the phone is still connected.

[greenleaf]

Just a quick update to wrap this up:

Tested charger on co-worker's 1st-gen iphone: works fine.
Tried another co-worker's iphone 4: works fine.
My iPhone 3GS: very hit-or-miss. I noticed that plugging and unplugging 4-5 times in a row seems to work sometimes. Right now it's charging and went from 85% to 88% capacity in the past few minutes.

Another data point: Once in a while my 3GS complains about "unsupported accessory" even with other chargers and devices. So I think it's fair to conclude that the problem could be the less-than-excellent build quality of the 3GS model iPhone.

[adafruit]

Another data point: Once in a while my 3GS complains about "unsupported accessory" even with other chargers and devices. So I think it's fair to conclude that the problem could be the less-than-excellent build quality of the 3GS model iPhone.

yes! the 3gs in our experience (using dozens of them for testing) was/is the buggiest iphone, all chargers have issues with this phone. so much so, we added a special note to the page.

"New version! Works with the new iPhone 4 and more! Please review the Minty Boost project page(s) before purchase and assembly!, some phones require different modifications to the kit to charge properly! Some phones such as the *iPhone 3gs are very sensitive to charging via USB and may not work in all environments or configurations. "

luckily, with the mintyboost you have a chance to specific hack/mod the resistor values to try to "tune" it to your phone, not always possible, but with a kit you have a chance

cheers,
adafruit

[greenleaf]

Thanks again, the forum replies and support have been excellent. I'll probably give this one away to someone with an iPhone 4, or just keep it until I upgrade. Not so keen on tearing it apart once it's already been built. Keep up the good work.

[jvschwarz]

First, Adafruit rocks!
Second, I'm sorry to report that I'm another unlucky 3GS "Charging is not supported with this accessory" victim. I read and understood your cautionary notes before I purchased and enjoyed the assembly task, so I'm still happy. I do have a few results to share with the cause. First, there are 3 - 3GS' and 1 - 2G Iphones in the family. The v3 Minty works great on the 2G but not on 2 of the 3GS'. I haven't tried it on my sons 3GS yet, but being the newest I'm suspecting it won't. My wife's is the oldest version of the 3GS' and with fresh Alkaline batteries it'll connect ~ok, readings of 4.69v and jumper'd D-/+ at 1.72 under load. When I checked the open circuit 4.95v and D-/+ 1/97 and plugged it back in , it wouldn't charge again. At least on my wife's phone it appears to be a battery issue. Haven't played with the resistors yet but look forward to more input. Since you've a couple Li-poly batteries listed, would it be possible to put another AA in series to up the combined voltage to 3.6v with rechargables? Do I need to make any modifications?

[adafruit_support_bill]

3 NimH cells (~3.6v) in series is a good power source for the Minty and will give you a some extra run-time as well. The only modification required is to solder on a 3xAA holder.

[jsappo]

Hey everybody!

I just encountered this same problem and fixed it!

It's a wonky dock connector straight up.

I have outlined the entire process for fixing it here on my blog at: http://www.johnsappo.com/blog/2011/7/24/iphone-3gs-fix-charging-is-not-supported-with-this-accessory.html

Hit me up with any questions.

Best.

[scott-42]

Nice writeup.

I love the screen shot at the end with the quote

I can power my iPhone now and it has the same great reception!

And the screen shot shows 2 bars. That made me laugh. I get the same "great reception" here.

[adafruit]

wow! we always thought it was something particularly picky about the 3gs - sometimes plugging it in again it 'suddenly works' - and the 4G had less problems.
Thank you for clarifying the problem - altho we're not sure we recommend everyone perform this fix

[xxhaxx]

You can try using a orignal USB cable from apple. I have 1 original and 3 third party and it seems like only the original would charge without any issues