What you need:
Rechargeable battery packs (the ones we are trying to fix)
a few paper-clips
A charging station or whatever you use to recharge your packs

Preparation
First bend your paper clip into a horse shoe shape, it is easier if you do a few

Draining the Battery pack
You'll see 6 pins on the battery of the battery pack.
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You need to use the horseshow paper-clip to touch pins 2 and 5 together (in red)
The paper clip will get hot, when it does either change paper clips or let it cool
Repeat this until there is no charge left in the battery (the paper clips will no longer get hot)

*When you first do this, you may find the paper clip doesn't get hot, keep pressing 2 and 5 together and you will begin to feel the heat*

To Reset the battery indicator circuit
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First touch pin 1 and 5 together (blue)

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Then touch pin 2 and 6 together (red)

Now you should be finished!

plug it into the dock and good luck!

If you are having difficulties heating up the paperclip, here are a few tips:
Reset the battery indicator (step 2) and then try heating them up again. If you've accidently touched pins other than 2 + 5 together then it may stop the charge from being released
use the length of the paperclip instead of the tips, as the tips may be worn down
Rub pins 2 + 5 with the tips of your paper clip to cause a bit of friction