DIY

@thedoc2025 That's weird. Do you have any packages like refloat/float installed in vesctool?
If so could you take a screenie of the appUI page when trying to balance?

@lia yep, i filled one in, too. : )

@studentde Hope you find many participants for the survey :) Just got done filling it in

@lucky E16 is commonly a broken wire in the harness between the battery box and controller. It can also be the chips either end of this cable on the BMS and Controller but it's less common.

Repair
You can either attempt to repair this yourself if you're somewhat handy or get a shop to look at it. If you reach out to local Onewheel FB groups they may have a go-to repair guy.

To do it yourself I'd start with testing and then replacing the harness with one from FM https://onewheel.com/products/xr-main-cable-harness.
If you're handy then you can attempt to find the broken cable and reseal the harness. It isn't fun but if you want to try that then @Lemur did something similar but ran an extra wire. The same principle applies for dissecting and splicing in a new wire. I'd suggest probing them first before starting the work.
https://owforum.co.uk/topic/144/plus-harness-to-xr-conversion-i-also-posted-on-fb

If there's no break then it's likely a chip either end and gets a little harder to do for most people.

Sell
In it's current condition assuming nothing else is wrong with it you may get an easy sell. A lot of DIYers like to buy faulty XRs to convert to VESC. The E16 on some conversions isn't an issue as the bits that went wrong can be worked around or go unused. Your local FB Onewheel group is likely the best bet to find a buyer.

@deeph Oh this might be a later model board where they removed that data :/
Give it a balance charge overnight and see if it improves much. Over time of leaving it a little longer after you see green you may claw back some range.

@deeph Congrats on getting more range back :)
Sometimes with batteries like this the cells can get out of balance. If you leave it on charge a little longer like a few hours or a day even it gives the BMS time to cycle the cells so they're all similarly balanced. I wouldn't recommend doing this a lot as keeping it fully charged for long times degrades lithium batteries.

If you use the OWCE app you can see the 15 cells and if they're all within like 0.1v of eachother. If they're all the same when it stops balancing then the battery is just worn out. However if you see just a few really low and others with power still then it likely needs a longer balance charge.

@lemur I cannot get enough of how cool your boards are.
The added light attachment is just

@imgermg If you can turn on the board you may be able to use the OWCE app to check voltage.
https://owce.app/install

If not the only other way to measure is to take it apart and measure with a multimeter at the battery connector.
I have labelled the 2 pins you can measure without unplugging the battery but be careful not to short them.

@quicksanddyoung 28000 Miles! Wow that's amazing. Congrats 🥳

@divouneh -- Instead of bumper wheels I've gone to the super slippery bumpers to good effect... That, reasonably conscientious riding, and safety gear make up my standbys.