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Battery life

Posted: Wed Dec 06, 2006 8:21 pm
by ibbo
Hi, guys:

I've been using my x60s for about 3 months now and have around 45 cycles on the battery. The battery capacity has gone from 73.6Whr to 67 Whr in that time. I only get about 4-4.5 hours on battery with wifi on and screen brightness on 1 bar. What can I turn off to maximize battery life? I would like to disable the fewest amount of services. Is there a list of options with largest gains? I'm using 2.05 or 2.06 bios.

-Jonathan

Posted: Wed Dec 06, 2006 8:39 pm
by tomh009
If you run the battery information applet, and unplug your AC adapter, you can see the power consumption from your specific devices as you turn things off. That is absolutely the best information as it's the hardware you actually have and not someone else's!

That said, you will get the lowest power consumption by hibernating. :) More seriously, hard disk uses a couple of watts so if you can minimize disk access to allow it to go to sleep you'll save there. 802.11 uses a few watts as well. Bluetooth uses a little bit when idle but much more when operating. Display brightness could save you a watt or two. Disabling Ethernet might save a bit, too.

Beyond that, you could use NHC or RMClock to reduce the CPU voltage; this will both get the X60 to run cooler, and to use a little bit less power. And both of those are good things!

Re: Battery life

Posted: Wed Dec 06, 2006 11:52 pm
by ozmann
ibbo wrote:What can I turn off to maximize battery life? I would like to disable the fewest amount of services. Is there a list of options with largest gains? I'm using 2.05 or 2.06 bios.

-Jonathan
I would check the excellent post by Lev on 9/30 in this thread
http://forum.thinkpads.com/viewtopic.ph ... highlight=
Process explorer from www.sysinternals.com is very helpful. Can you get below 10-11 W (as measured in Power Manager|Battery Info when running on battery)?

Good luck,
ozmann

Posted: Thu Dec 07, 2006 1:33 am
by ibbo
Thanks, I followed the suggestions outlined in the link and my wattage is definitely around 30-40% lower. I wish I had inquired about this earlier since my battery probably wouldn't have lost so much capacity over the course of three months. By the way, what's the average loss of capacity on a full discharge/recharge?

Thanks again for the help!

Jonathan

Posted: Thu Dec 07, 2006 6:01 am
by tomh009
There is no good rule for how much a battery loses in one discharge cycle, and what you will see is the capacity dropping infrequently but in larger amounts.

My X31 battery is at about 75% capacity after almost 700 cycles.

Posted: Thu Dec 07, 2006 9:22 pm
by ozmann
ibbo wrote:By the way, what's the average loss of capacity on a full discharge/recharge?
Lithium batteries do best if they are not fully discharged. Cycling to full discharge causes much more of a capacity loss than discharging no more than to 20% or so. Similarly, charging to full capacity also is not ideal, though it often is necessary. For extended use on AC, the battery does best if it sits at 40-50% charge.

If I'm mostly running on AC with short intervals of battery use, I set the lower threshold for starting battery charging to 30% and the upper charge point to 80%. The battery charge drifts down during use. If I am going to need longer battery run time, I readjust the thresholds to take the battery to full charge.