New Battery toggling between "charging" and "not charging"

Hi

I replaced the battery on my Gateway MA8 with a brand new one (non OEM). With the laptop turned off, the new battery charged well without any problems. But when I charge the battery with the laptop turned on, I see the battery icon changing from "plugged in-not charging" to "not plugged in" to "plugged in-charging" and the cycle repeats. The charging LED indicator also keeps turning off and on, following the icon messages (this indicator was constantly on when charging with the laptop turned off). Looks like the battery charging is getting messed up when Windows 7 is trying to monitor the status.

Applications also are exhibiting a strange behavior during this time. I had started a virusscan and whenever the battery icon changed to "not plugged in", the virusscan used to pause and would resume when the icon changed to "plugged in-not charging" or "plugged in-charging". Very weird!

I uninstalled the Battery ACPI driver through Device Manager, but that did not help. The other battery drivers are reporting up-to-date versions.

I tried removing the battery altogether and connected directly to the power. It works for sometime and then suddenly the laptop shuts off. So cannot use that solution either.

One other data point is that the original battery was 11.1V 4800 mAH (53 watt hours), whereas the replacement one is 10.8V 5200 mAH (56 watt hours). But it has the correct battery model number. Could this be a cause? I had thought this difference should not matter.

Any help on how to fix this?

Thanks very much.

Thanks for the reply. A bad battery was my first thought too, but it is charging fine when the laptop is turned off. The problem is only when the laptop is turned on. Looks like some problem when Windows is actively trying to monitor the battery status....