Overvoltage

Your battery is full. You brake going downhill. Regenerative braking pushes energy back into the battery. But the battery can’t accept more charge - the voltage climbs above the safe maximum. The BMS intervenes.

What happens

Depending on the wheel: aggressive tiltback to prevent further braking, reduced braking power, or in extreme cases, a hard cutoff. Some riders have reported unexpected behavior - the wheel essentially refusing to brake properly to avoid overvoltage.

The classic trap

Start a ride at the top of a hill with 100% charge. First thing you do is brake downhill. Regen has nowhere to go. This catches riders who charge overnight and leave from elevated areas.

555 take

Never start a downhill ride at full charge. Charge to 80-90% if your route begins with a descent. Or ride flat for a few minutes first. Overvoltage is the mirror image of low battery - both shrink your safety margin, just from opposite directions. The regen deep dive explains what the wheel can and cannot do when braking energy has nowhere to go.