@Ottohoff what is the new charger? What are its specifications?

There is a bit of tech in the charger to control the charge rate during the charge cycle that you will lose by using a generic charger.

@OneDan Done!

@wheelrich great. I'll take a look at that fender, thanks

Six months back, my tire was slowly going flat every three days. Then one morning it was flat even though I pumped it up the night before.
I unscrewed the valve stem and squirted about 4 oz. of additional Slime into the tire, cleaned the threads and screwed the stem back in. Been riding strong ever since, no leak, no wobble, no new tire after probably another 400 miles..

I've had exactly the same "bad luck" with my new OW +...
Had to send it back to Future Motion.
It's still by them for repair...
The batteries appeared full and no problem could be red through the App.
I suppose it might be a electronic card problem or something else between the battery unit and the engine as it seemed fully charged...rolled for a few meters, then the alarm rang saying : "Empty battery" and the board stopped immediately.
Good luck ;-)

@carterw I don't know of a way to reset it, but the nose up sounds like either you are in Elevated mode (you can change this from the app), or something is wrong with the board and you should email support about it.

These people had similar problems, you could ask them what they did:
http://community.onewheel.com/topic/1997/nose-up-tail-down-malfunction/1

http://community.onewheel.com/topic/1953/sensor-side-of-the-board-is-too-low

@chunibuni

Here you can find small tutorial:

http://transistor-man.com/flying_nimbus.html

Some theory:

https://en.wikipedia.org/wiki/Inverted_pendulum

Some more:

http://ctms.engin.umich.edu/CTMS/index.php?example=InvertedPendulum&section=SystemModeling

Motor is located in wheel. OW is using gyros and accelerometers and probably Kalman filters and PID controller. Have fun building your own version! :)

Very simple app...a 10 second video could cover it.