Symptoms
- Fully charged power bank drains to empty within hours unused
- Charging indicator drops rapidly once unplugged from output
- Bank is more than 2–3 years old with regular use
- Charging itself still seems to work normally
Likely causes
- CommonBattery cells have degraded from age and charge cyclesLithium-ion batteries typically lose significant capacity after 300–500 full charge cycles.
- PossibleInternal self-discharge has increased with ageAging cells can leak charge internally even when not connected to anything.
- PossibleBattery has developed a fault from heat exposure or physical damage over timeRepeated exposure to heat, like a hot car, accelerates degradation.
- Less commonManufacturing defect causing early failureOccasionally a unit fails well before its expected lifespan.
What to do
- Fully charge the power bank and then let it sit unused for a few hours to measure how much charge it loses just sitting idle.
- Compare its held charge and runtime to when it was new, if you remember, to gauge how much capacity has actually been lost.
- Check for any physical signs of damage, swelling, or heat exposure history.
- There's no home fix for degraded lithium cells; battery capacity loss from age isn't reversible.
- Consider replacing the power bank once it can no longer reliably provide a meaningful charge, and recycle the old one at a battery drop-off point rather than the trash.
Tools and parts
- None required
Replacement power bankSearch: “portable power bank charger”
When to call a pro
No repair path for age-related lithium battery capacity loss; replacement is the practical solution.
Safety
Generally low risk
Generally low risk for a careful person. Stop if anything looks different from what this guide describes.