iWonder.. battery drain

[Jeroend42]

Hey all,

I wanted to build a Mintyboost to charge an iPod Shuffle and a Kindle. Now, when I try to use it this happens:

1. With (new) AA-batteries the charging light goes on, but the battery starts decharging - pretty rapidly (both from the iPod shuffle and the kindle).
2. After I recharged the iPod through a computer, exactly the same happens. Charging light on, until the battery's dead and then the light goes off.
3. Without batteries in it nothing happens at all.
4. Also, when I put in an iPod Touch I get the infamous "this silly phone doesn't know how to handle your awesome charger"-message. I did however connect the two USB-thingies.

Do you have any idea what might have gone wrong? Here are some pictures:

[adafruit_support_bill]

There are a couple of cold solder-joints on the back-side. Use a clean, hot iron and re-touch any that are not smooth and shiny.

What voltages do you measure on the USB terminals? Do these change when you connect the phone?

[Jeroend42]

Thanks for your answer! I tried to clean up the soldering a bit, but still the same thing is happening.

Without the iPod Shuffle connected I've got 4.98 between the first and last pin, and 1.97 between the first and the big blob in the middle. When I connect the iPod the 4.98 doesn't change but between the first and the middle it goes down to about 0.49

[adafruit_support_bill]

Your voltage output sounds perfectly good. Not sure why the center-pin voltage would drop like that though. You might try a different cable.

[Jeroend42]

I tried three different machines, each with their own cable. With the iPod Shuffle and the Kindle the battery still depletes very quickly. When I connect an iPod Touch I still get the same error message that it can't charge, and these voltages: 5V between the first and last, and 1.80 between the first and the middle, so a little bit lower than without the iPod.

[adafruit_support_bill]

Not sure what the problem is. As a charger, your measurements say that the MintyBoost is doing exactly what it needs to do: ~5v charge voltage and ~2v on the data lines. If the primary voltage is not dropping when the load is connected, then there isn't any more that the MintyBoost can do.

Double check your measurements and the calibration of your meter.