Causes
- Stability band not seated correctly — This is Bose's own most-cited cause. The QC Ultra 2nd Gen earbuds pair a stability band with the eartip. If the band is twisted, popped off, or lined up off-center, the earbud does not drop fully onto the two copper charging pins recessed in each case well. It looks seated but makes no electrical contact, so the bud never charges and its status light stays off.
- Charging pin stuck compressed in the case — A known failure on the QC Ultra line: the spring-loaded pin in the left case well can jam in the down position, usually after the earbud was dropped in at an angle. The pin no longer springs back up, so it cannot touch the charging contact on the bud and the left earbud silently stops taking a charge.
- Dirty or corroded charging contacts — The two gold contact pads on each earbud nozzle and the pins in the case collect skin oil, earwax, dust, and pocket lint over time. A thin insulating film is enough to block the low-voltage charging circuit without triggering any error message. Debris jammed in the case's USB-C port also stops the case itself from recharging.
- Case battery fully drained or on a weak source — The case holds roughly 3 full charges. If it was left empty, or the earbuds were charged off a laptop USB port or a low-watt phone brick, the charging circuitry may not get enough current to start topping up the buds. Qi wireless charging also fails silently when the bud is not centered on the pad or a case sits between it and the pad.
- Earwax guard blocking the nozzle contact — The 2nd Gen ships with earwax guards over the nozzle opening. If a guard is loose or rotated, it can sit between the charging contact pad and the case pin, breaking the contact on that side only.
How to Fix
- Remove both earbuds and re-seat them with the band aligned — Take each earbud out and check that the stability band is flipped over the nozzle correctly and sits flush. Line the earbud up with its marked slot (L and R are stamped inside each well), press down until it clicks fully home, and close the lid. Watch the bud's status light or open the Bose app: it should switch to the charging animation. This resolves the most common alignment cause.
- Hygiene clean the charging contacts — Dampen a cotton swab with 70% isopropyl alcohol (never water, never insert it wet into the case). Wipe the two gold pads on each earbud nozzle and the pins inside each case well, then dry with a lint-free cloth. Blow short bursts of compressed air into the case's USB-C port to clear lint. Do not scrape the pins with metal; the spring contacts are delicate.
- Pop a stuck charging pin back up — If only the left bud refuses to charge and the other charges fine, inspect the left case well. Gently use clean plastic tweezers to push the compressed pin up and coax it back to spring height. Seat the earbud and confirm it clicks in. Fix the pin before relying on the case, because a jammed pin will also slowly drain the case battery through shorted contact.
- Reset the earbuds — With both buds in the case and the lid open, press and hold the touch control on each earbud at the same time for about 30 seconds. You will first hear a low tone, then a voice prompt confirming that the Bluetooth device list has been cleared. This reboots the power management and reseats the charging handshake with the case.
- Charge the case, not just the buds — Plug the case into a certified USB-C charger rated 20W or higher (not a computer port), or center it correctly on a Qi pad with no metal between it and the coil. Confirm the case's charge LED actually lights. A case that is itself dead can't top up the buds no matter how clean the contacts are, so prove the case is charging first.
- Contact Bose Support if a single bud still will not charge — If one earbud verifiably never charges even after cleaning, pin inspection, and a reset, the charging contact on that bud or the case well is damaged. The QC Ultra 2nd Gen carries a 1-year warranty; Bose Support (bose.com/support) will arrange a repair or replacement of the bud using its serial number rather than asking you to open the sealed unit. Do not pry the case apart yourself, it will void any remaining warranty.