My NB520 has recently developed a problem.
It was working fine and i charged it up to 99% then when i removed the charger, a message appears saying ''0:05 of battery remaining (99%)'' and then ''computer will suspend very soon unless it is plugged in''.
So even though it is registering the 99% charge it thinks there is only 5 minutes of operation time left.
Is this a battery problem or a motherboard problem?
For me it looks like a battery malfunction…maybe you could try to calibrate the battery several times in order to increase the performance but not quite sure if this would help in this case…
To calibrate the battery you should discharge the battery until it would be fully empty. Then charge it again until the battery indicator would switch to blue or green (this depends on model you have).
If this would not help, I would recommend testing new battery.