Symptoms
- Power bank shows charge remaining but phone doesn't charge
- Phone charges very slowly from the power bank
- Connecting makes a clicking or reconnect sound repeatedly
- Works with one phone but not another
Likely causes
- CommonCable or port not carrying enough currentSome power bank ports are output-only or low-amperage and won't fast-charge newer phones.
- CommonDamaged or low-quality cableA cheap or worn cable is a frequent hidden cause of weak charging.
- PossiblePower bank's remaining charge too low to registerSome units cut off output below a certain internal charge level.
- PossiblePhone case blocking the connectorA thick case can prevent the connector from seating fully.
- Less commonPower bank output circuit failureInternal damage can disable one or all output ports.
What to do
- Remove the phone case and confirm the cable is fully seated in both ends.
- Try a different cable, ideally the one that came with the phone.
- Check the power bank's own charge level; recharge it fully and try again.
- Try a different port on the power bank if it has more than one.
- Test the power bank on a second phone to isolate whether it's the bank or the phone.
- If no port charges any device, treat the power bank as faulty.
Tools and parts
- Charging cable
- Phone (for testing)
Replacement power bankSearch: “portable USB power bank”
When to call a pro
No repair path for a failed output circuit; replace the power bank if testing rules out cable and case issues.
Safety
Generally low risk
Generally low risk for a careful person. Stop if anything looks different from what this guide describes.