I'm experiencing the same problem with my 9100.  When I go on battery power the power meter continues to show 100%, and suddenly the system just shuts down.

My Inspiron 1100 has sort of the same problem. Only it doesn't show a battery icon at all. It only uses the AC Adapter plugged in icon.

I have had the same problems intermittently recurring on my Inspiron 9100 since I got it in May.  Many times when on battery, either the battery icon shows 100% or it shows "on AC Power" until the laptop dies.  I hate it.  I upgraded the BIOS to A02 and have all the latest WinXP (automatic) updates.  I use the suspend function on the keyboard sometimes and I am not sure if that is related.  But what good is a laptop if you can't suspend it now and then?  I called Dell support and they recommend the A03 BIOS update that was recently released.  I am not hopeful because the release notes say nothing of a fix for battery power metering, but I will try it and post results in a day or two.

One other thing that is bugging me is the battery (with integrated subwoofer) has never lasted more than an hour.  If I play a DVD movie it lasts an hour.  If the only connection in use is the 10BaseT ethernet (browsing internet) it lasts an hour.  The screen is set to dim a bit when on battery.  I have tried to optimize the settings to keep power consumption down but it must not be working.  I don't use Quickset - I use the WinXP power options.  http://www.itworld.com/Tech/2987/040528umbrella/ reviewer got 2.5 hours from his battery.  I would be happy with 2 hours.  Any suggestions?  Is there a way to tell if the DVD+R drive is spinning?  If so, can it be stopped?

I feel like I'm part of a broken record here. My power meter for my battery has never worked. I tried letting it run all the way down and then recharging it, but it always remains at 100%. It would be nice to get this worked out so I would know when my battery is about to die.

I ended up calling Dell and after a useless BIOS upgrade they suggested, I demanded they send me a replacement (since it's still under warranty). The replacement battery works fine, but I am experimenting with ways to milk more time from the battery.

I also want to be able to use the 9100 on road trips to play DVDs for my daughter. I need to be able to play DVDs for up to 6 hours. But my 300W inverter barely seems capable (and it includes a 12V battery as well). The power brick for the 9100 is almost hot enough to burn when it's being used (in a wall outlet or inverter).
http://notebookforums.com/archive/index.php/t-30223.html
The above link has some interesting info about auto inverters for the 9100 and I guess I will not continue discussing it here (but may post to a corresponding topic on this forum instead).

My battery icon isn't there. It is checked in the power options. It used to be there but once I installed SP2, it stopped appearing. The alternative I use is Fn+F3. I guess if the problem is that the bat always shows 100%, it would show in there too... any ideas for getting my battery icon back?

 

Dell 9100/ 3ghz w/ HT, 40gig HD, CD-RW/DVD +/- RW, Win XP Pro w/SP2, 512meg RAM, 64meg VID