Power Training

When you bring a low leveled friend (in a video game) to a high level area to train them really fast.

or

pulling an all nighter to train your character(s) to a higher level to make a boss or level easier.

"Dude, thanks again for power training me now i can hold my own against level 54 monsters."

or

Mom- "What are you doing up? it' 4 in the morning?"
Child- "I'm power training so i can beat the demon and save the 5th demension!"

Battery-fail

when you get a game over in a video game because the batteries in your controller died.

"Ahh, i was so close to beating this boss when i suffered a battery-fail. and i couldn't find my spare ones quick enough."