-( Story related, cannot be missed )-
*While this is "flagged" as possibly story related, the real note is that... you could scrape by without having all 101 Power Cells early on. It would be in your best interest to avoid back-tracking at the end to get this for the final ending. I would advise doing this as soon as possible, as the Blue Eco vents help out, so the sooner the better, as Blue Eco aids in the collection process.
Level: Precursor Basin
Dotted through Precursor Basin are Flying Lurkers. You will need to run all of them over for the last one to provide you a Power Cell. They will run in specific paths given the location you find them, and the only way to truly catch up to them would be to keep on their tails. When you catch up, you can just run over them, or use the Zoomer to jump up and mow it over. Once you mow the last one of four, you will complete the task and net yourself another Power Cell.