The short answer
Clean the charging contacts on the earbuds and inside the case, because a film of earwax and skin oil is the most common cause by a wide margin. Then check the buds are seating fully, test whether the case itself is holding charge, and clean the case’s own charging port of lint.
The charging path has four links: mains to case, case battery to contacts, contacts to earbud contacts, and earbud contacts to its battery. A failure anywhere looks the same from outside, and checking them in order takes a couple of minutes.
Step 1: the contacts
This is the answer most of the time. Earbuds live in ears and then go into a sealed case, which is an excellent way to transfer wax and oil onto small metal contacts.
Look at the contacts with a light
Both the small pins or pads inside the case wells and the matching contacts on each earbud. A dull film or visible residue is what you are looking for.
Clean with a dry cotton bud
Rubbing firmly. For stubborn film, a cotton bud very lightly dampened with isopropyl alcohol, then left to dry completely before charging.
Use a wooden toothpick around the edges
To lift debris from the bottom of the wells, which is where it accumulates.
Check the magnets are holding the buds down
If a bud sits proud, it is not making contact. Debris under it is usually why.
Test each bud separately
Put one in at a time and see whether it charges. One failing and one working narrows it immediately.
Never use water or a metal tool on the contacts. Water bridges the contacts and can corrode them permanently, and a metal pick bends the spring pins, which is not repairable. Dry cleaning with a cotton bud and a wooden toothpick is the correct approach.
Step 2: is the case itself charged?
The case has its own battery, and it can be flat, or ageing to the point where it holds very little. Signs:
- The case indicator shows low or nothing when you open it.
- Earbuds come out at 60 or 70 percent after a full night in the case.
- The case discharges noticeably when left unused for a few days.
- Charging the case fully gives you one set of earbud charges rather than several.
Charge the case on its own for an hour and watch whether the indicator behaves as documented. A case battery is not usually replaceable, which is a real limitation of the category and worth knowing before you spend time troubleshooting.
Step 3: the case’s charging port
Cases go in pockets and bags, and their USB-C ports collect lint exactly as a phone’s does. A cable that does not click in fully, or charges only at a certain angle, is the sign.
Clean it with a wooden toothpick, powered off, without touching the central contact strip. Then test with a different cable and a different charger, since both fail and both are cheap to eliminate.
If the case supports wireless charging, test that too. A case that charges wirelessly but not by cable, or the reverse, tells you exactly which part has failed.
Step 4: the software side
- Reset the earbuds, which clears a state where a bud fails to sleep and charge properly in the case. The method is usually holding the case button for ten to twenty seconds with both buds inside.
- Check for a firmware update, since charging behaviour is firmware-controlled and problems do appear and get fixed.
- Check the reported levels in the app, which may differ from what the case indicator suggests.
- Beware of stale readings, where the phone shows a cached battery level rather than the current one. Disconnect and reconnect to refresh.
Step 5: moisture
Earbuds used at the gym go into the case damp, and moisture on the contacts prevents charging and corrodes them over time. If the buds have been sweaty, wipe them and let them dry before closing the case.
A case that has been damp inside may need a day somewhere warm and dry, ideally with a silica gel packet, before it charges reliably again.
Make a habit of wiping the earbuds with a dry cloth before putting them away after exercise. It takes five seconds and prevents the single most common cause of charging failure in this category, which is a contact film built up over months.
When it is a hardware failure
If one bud charges and the other does not, with both sets of contacts clean, that bud or its well has failed. If neither charges and the case holds power, the case’s charging circuitry has failed.
Replacement cases are available separately for some models, which is considerably cheaper than a new set and worth searching for. A single replacement earbud is also available from several manufacturers. Neither is universal, and both are worth checking before replacing the whole product.
Why does only one earbud charge?
Usually a film on that bud’s contacts or debris in its well preventing it seating fully. Clean both and check the bud sits flush with the magnet holding it down.
Can I clean the contacts with alcohol?
A cotton bud very lightly dampened with isopropyl alcohol is acceptable, left to dry completely before charging. Never use water, and never use anything metal.
How do I know if the case battery is worn?
If a fully charged case gives only one charge to the earbuds rather than several, or discharges noticeably when left unused, the case battery has aged. It is rarely replaceable.
Why do the earbuds show the wrong battery level?
The phone may be showing a cached reading. Disconnect and reconnect to refresh, and check the level in the manufacturer’s app rather than in the system status.
Can I buy a replacement case?
For several popular models, yes, and it is far cheaper than a new set. Search your exact model before assuming the whole product needs replacing.
The order
Clean the contacts on both the buds and the case wells, dry, and check the buds seat flush. Test each bud separately. Charge the case alone to see whether it holds power. Clean the case’s charging port and test a different cable. Reset the earbuds and check the firmware. And if one bud or the case has genuinely failed, look for a replacement part before replacing everything.
