I participated in the limited-run prototype fundraiser for the coolest product on the planet, the electree, last year and thought I'd share a little hack I did to effectively increase the battery capacity & protect against the dreaded 'battery can't charge because it has no battery' bug that occurs in many devices including some cell phones, the original cr-48 chromebook, and a few first-gen//prototype electrees purchased on ulule.com.
A quick aside- electree just launched a Kickstarter today! They will be giving all Ulule.com backers (like me) a 'significant discount' on the new electree (the electree+). Scroll down to the Risks and Challenges section.
Firstly, note that you can easily jumpstart most batteries by shock-charging with a power source - in the case of the Chromebook, you simply insert & remove the power cable gently repeatedly ~10x until the light comes on, then let it charge. For the Electree, it's much simpler - you simply plug in the USB port on the underbelly to a wall USB adapter or backup battery like this. Instant fix.
While I was at it, I decided to both increase the battery capacity and prevent the charging bug by permanently installing a secondary battery. I opened up my 'chargers, batteries, and sparqs' bin and found a few options:
A little $10 Energizer that alone really doesn't serve much purpose and larger newtrent and zagg battery-chargers. I decided to put the Energizer to use, as I still sometimes travel with one of the others.
Start by removing the tree portion and flipping the base over:
Next, remove the rubber feet and unscrew the 4 screws:
Pry off the panel:
At this point I wasn't quite sure where the new battery might fit, so decided to tackle the wiring first.
You can remove the bottom-side USB port by unscrewing the 2 screws and severing the glue:
(Initially done to snake the new USB cable through)
I experimented with threading the Energizer's USB cable through the main USB panel after removing the main computer board:
But after a bit decided it would be too difficult to access the battery, and figured I'd make a more flexible solution. After removing the bottom-side single port, thread it through the inside dual USB port panel by first removing the board (it has 2 screws):
Screw the board back on, and secure the 3rd USB port down (I used hot glue)
Now you can hook up an extra battery to the electree, using the repositioned 3rd USB port to charge the electree, and one of the other two USB ports to charge the battery.
I ended up swapping the Energizer for a larger capacity NewTrent, giving me ~20,000 mAh total :)