Symptoms
- Laptop powers on fine with the battery installed, even at low charge
- Laptop does nothing when running only on the charger with no battery
- Removing the battery was intentional (e.g. to test or replace it)
- No lights or fan activity when trying to run on AC alone
Likely causes
- CommonThe laptop model requires the battery present as part of its power delivery designSome laptops route power through the battery circuit even when charging, so it won't boot without one installed.
- PossibleCharger isn't providing enough power to run the laptop directlyA lower-wattage charger might work fine to trickle-charge a battery but not to run the laptop alone.
- PossibleBattery removed incorrectly, leaving a connector unseatedIf the battery was reinstalled, an unseated connector can also cause this.
- Less commonBattery connector or charging circuit faultWorth considering only if the laptop also had trouble with the battery installed.
What to do
- Check your laptop model's specifications or manual to confirm whether AC-only operation without a battery is supported at all.
- Reinsert the original battery, or a known-working one if you have it, and confirm the laptop boots normally.
- Try the laptop's original full-wattage charger if you were testing with a lower-power one.
- If AC-only is supposed to work on your model, check that the battery connector inside is fully disconnected and not partially bridging the connection.
- Accept that many laptops, especially thin-and-lights, are designed to always need a battery present.
Tools and parts
- None required
When to call a pro
If your laptop model is documented to support AC-only operation and it still won't power on that way, have the power circuit checked by a professional.
Safety
Generally low risk
Generally low risk for a careful person. Stop if anything looks different from what this guide describes.