Hey, I have I believe an Osmo mobile 1 or could possibly be a 2, not sure.
Its been used maybe once about two years ago, I can't get it to turn on or even register that it's charging.
I have two batteries btw, and I've tried many different USB ports any help would be appreciated

You have an osmo mobile 1 judging by your avatar.
Have you used the USB => mini jack cable that was supplied with the Osmo Mobile?

Or do you charge with a separate charger ?

Hi, I am sorry to know that you are having issue with your  DJI Osmo Mobile .Please try to wipe the copper sheet of the DJI Osmo Mobile battery with a 95% alcohol cotton swab. Let the alcohol air dry before turn on the battery. If the issue persists, we recommend to send the unit in for further evaluation, our repair team will help to locate the problem and help you out. Keep us updated. Thank you.