Symptoms
- Indicator lights don't turn on when plugged in
- Lights blink but never reach full
- Takes far longer than the rated charge time
- No lights at all, ever
Likely causes
- CommonCharging from a low-power USB portMany power banks charge very slowly or not at all from a laptop or hub port.
- CommonFaulty or underrated charging cableA thin or damaged cable can't carry enough current to start charging.
- PossiblePower bank has fully discharged below its safety cutoffVery deep discharge can put some units into a protective sleep state.
- PossibleInternal battery cells have degraded with agePower banks lose capacity over 2–4 years and may stop taking a full charge.
- Less commonCharging port or internal circuit failurePhysical damage or a manufacturing fault can disable charging entirely.
What to do
- Plug the power bank into a wall adapter rated at least 2A instead of a computer USB port.
- Swap in a different, known-good charging cable.
- Leave it plugged in and untouched for 30–60 minutes in case it needs a slow trickle to wake up.
- Try pressing and holding the power button for 10–15 seconds to reset it, if the model supports that.
- Check the manual for what the indicator light pattern actually means, since some blink normally while charging.
- If it still shows zero response, the internal battery or circuit has likely failed.
Tools and parts
- Wall adapter (2A or higher)
- Charging cable
Replacement power bankSearch: “portable power bank charger”
When to call a pro
There's no economical repair for a dead power bank's internal battery; replace the unit rather than paying for service.
Safety
Generally low risk
Generally low risk for a careful person. Stop if anything looks different from what this guide describes.