Two likely candidates: Belt or tread. Lubricating the tread would be the easiest starting point; but if you're running at 7 or more you've probably already thought of that.
If the cover isn't too difficult to remove, you can expose the drive belt and the squeaking volume change would be an indicator that the drive belt is the problem.
We are FIXYA dot com. We are not Precor and we certainly don't take credit card numbers. By 'charging bat', you mean battery for the display. The battery is mentioned 67 times in the manual. Press CTRL+F and type in 'battery'. Page 39 and 40, looks to be what you need.
https://primofitnessusa.com/wp-content/uploads/2017/01/V3-precorefx-546i-V3-elliptical.pdf
Links to Precor if you need to buy something?
Durable 6-phase generator system has no contacting parts, reducing friction and wear, and provides 20 levels to tailor workouts with consistent resistance. The 20 ...
The Precor EFT 546i elliptical has an adjustable cross ramp that allows users to select an angle between fifteen and forty degrees. This allows for isolation of the ...
..
It might be the battery. A fully charged battery is required to move the ramp up and down. The battery is like a car battery, if you don't use it then it dies and might need to be replaced.
you found the right place buddy.. i know a lot of websites for repairs and manuals that can really help u.. try www.reliable-store.com 's live assistance 24x7
