Hello, I bought a new laptop battery as the original one was oly lasting about 4o mins, with the adaptor plugged and the new battery in, the battery icon says its at 55% and charging but as soon as I take the adaptor out the laptop looses power
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Is it an official battery or 3rd party. Sounds faulty to me. We sometimes sell IBM batts at my shop and have to change them for different models just to get them to work even though they are the same as the one we replaced.
Remove the battery. Start the laptop without the battery. Turn it off. Put the battery. Let it charge. Try again. This might help.
It happened to me once. Years ago with a new laptop and battery. It was a firmware bug I think and they fixed it later.