Battery lasts longer with Ubuntu than Windows?

[Mr-Pacman]

I found this quite interesting....

I bought a used X31 today for $100. When I load up Windows XP and check the battery health, it's "yellow" with 289 cycles. I did 4 cycles today and got about 45 mins from the battery before windows shut down on me.

I then installed Ubuntu (dual boot) and ran the battery down in windows (it was showing 5% on the gauge). Then, I booted up in Ubuntu and it also showed low battery (1.5% remaining) but I was able to get another 30-40 mins out of the battery on the 1.5%.

Does this mean my battery is stronger than Windows is showing? Is there any way to re-set the battery gauge so I can get the full power out of the battery on windows? If not, I'll probably just use Ubuntu as the only O/S as the extra battery life is helpful.

[sojourner]

I found this quite interesting....

I bought a used X31 today for $100. When I load up Windows XP and check the battery health, it's "yellow" with 289 cycles. I did 4 cycles today and got about 45 mins from the battery before windows shut down on me.

One other important consideration of Li-ion batteries is age. Generally speaking, after three years they start deteriorating even sitting on the shelf! The battery shelf life does vary from manufacture to manufacturer though. I've found Panasonic cells to consistantly be FAR superior to any other. So how old is the battery?

I then installed Ubuntu (dual boot) and ran the battery down in windows (it was showing 5% on the gauge). Then, I booted up in Ubuntu and it also showed low battery (1.5% remaining) but I was able to get another 30-40 mins out of the battery on the 1.5%.

There can be a number of things causing your experiences, for example:
- what thresholds do you have for low battery in Windows? In Ubuntu? Are they the same?
- what functions are specified in each OS when a low threshold is achieved? Are they the same?

IBM by default has an initial low battery threshold for Windows set to 10%, which I think is too high. 5% would be more realistic (and better for the battery). My systems are set for simple popup and sound notification. Then the same alarm comes up at 3%. Then I take the initative to shut-down or whatever.

What is your system setup like? Are you allowing default settings to hybernate your system? If so at what threshold? And Windows settings may be different (higher) than Linux, thus it looks like longer battery life in Linux.

answered within in BOLD

Does this mean my battery is stronger than Windows is showing? NO Is there any way to re-set the battery gauge NO so I can get the full power out of the battery on windows? If not, I'll probably just use Ubuntu as the only O/S as the extra battery life is helpful.

My guess is that the threshold levels for low battery are different for Windows / Ubuntu. You can make them the same!

Also, and this is important, check to see your power saving settings are the same between the two OS's. The battery meter in Windows will tell you how much current is being drawn whilst on battery. My TP's normally draw somewhere between 7-9.x watts. If lots of disk activity 11-12w (if I remember correctly). How much power is being drawn on your Win setup? Ubuntu setup? This makes a BIG difference in battery life!

Lastly let me add this, when I have a battery that has a short life, sometimes that short life is caused by only one bad cell in the pack. Because of the bad cell battery voltage falls quickly making it look like you'll have little run-time BUT, if you set low-battery thresholds to only give alarms (not shut-down the lappie) you may see a much longer battery life. There's one battery here that even when the battery gauge shows 0% (ZERO), will run for 30min-1 hour more! Reason is, there is a bad cell inside, voltage is low so the battery meter shows 0% life, yet there is enough voltage and PLENTY of current capacity in the good cells to keep the laptop running for much longer (hope all this isn't too technical).

SUMMARY:
Check both OS's and be sure thresholds are the same. Check power settings for WIFI, USB ports, CPU throttle etc are the same too. You may want to NOT have the OS automatically shut-down upon low-battery, and instead you deside when is the time.

[Mr-Pacman]

Thanks for the reply Soujourner.

You were bang on......I turned off the critical warnings in Windows XP and let the battery run down, and I was able to get another 30 mins out of it once it had hit "0% remaining". There must be something wrong with one or two of the cells (since it's roughly charging at 30% capacity).

Now I'm just trying to decide between running Windows XP or Ubuntu as OS on this machine. I'm only going to be using it for internet browsing and email so I'm tempted to go with Ubuntu. However, the factory install of XP seems to be very fast which is surprising considering the X31 has 512megs ram, 1.3ghz and a 4200 rpm 20 gig drive.

James

[sojourner]

Glad to hear it worked out!

So you are trying to decide between XP and Ubuntu? Could be tough. You didn't mention which version you're using. I went to Intreped shortly after it came out but to be open, I use XP or W98 most of the time because of software designed for those OS's.

You mentioned "the factory install of XP seems to be very fast which is surprising". Have you trimmed the services down to the minimum you need? You'll see an even BIGGER improvement. Plus there all kinds of performance optimizations for XP ... here's one you'll like:
http://forum.thinkpads.com/viewtopic.ph ... 5&#p497755

All the best!