Powermonger: Gold

I've made a video on how to complete this achievement:
Darkmoon Faire Achievement: [Powermonger: Gold]

TL;DR Use Battery once to store next powerup hit, use it again to use the powerup.

Battery isn't explained that well by its tooltip. When you use it you'll gain a buff called "Battery" that will store the next powerup you hit within four seconds instead of having it affect you. When you have a powerup stored you gain a buff called "Powerup Stored" and you'll have the icon of the stored powerup over your head. It seems you can keep a powerup stored indefinitely. Using Battery a second time uses the stored powerup immediately.

As of when this comment was posted you can also store a powerup, abandon the race, and keep the powerup. This is useful for grabbing the speed boots to start the race with, for example.

This has been the most annoying of the racing achievements for me and it's the only one I don't have. Just spent about an hour on it and so many times the counter has flipped to 12 right as I am about hit the finish line. I'm about to start breaking inanimate objects so I think I will try again next month.