Ultrabay Battery doesn't increase run time...HELP

[WhoDat]

I recently purchased an Ultrabay battery for my T42 thinking that it would greatly extend the battery usage time. Well, I'm a little confused, when I first turn on the computer after a full charge it shows about 6 hours of battery time. Then within the first few minutes it drops back to the time I had before the battery, about 3 hours.

I have checked to make sure that the new battery shows up in the system and it says Battery #1 discharging, Battery #2 Charged. But it doesn't seem to add any useful time.

Any idea if I need to update a driver or something? Thanks.

[ctbenski]

Have you actually completed the discharge and measured the run time? Or is the time the estimate that Windows or, say, the IBM Battery Meter shows?

I have found that neither of these are correct, sometimes they would indicate 2.5 hours and the actual run time would be well over 4 hours on my T41 (standard 6-cell battery, all unnecessary devices off, all power save settings to max).