Thinkpads Forum

Hello everyone,

Well, I've decided to write to you to get some info about this laptop.
But firsty, I want to appologize for my bad English: not my native language.

So, listen to my coolstory:

About an year ago I've bought my Lenovo X61s and on the same day I've installed Ubuntu 9.04 there. Lifetime with ubuntu was about 1.5-2 hours, but I didn't pay attention to it. Btw, battery is 28800mWh. But then lifetime decreased to ~1 hour and only then I've decided to look what's with the battery. As you might see, battery's capacity decreased almost for 50%! IMHO, it's not right, or is it?
Usually, I was using my laptop with AC adapter plugged in, but sometimes(not often) I took it with me to the university and used there to it's full discarging.
Somewhere in the net I've read that if battery capacity changes more than 5% per year, you should call the support and they have to replace it. I've phoned them, but it was useless. They told me that if thinkvantage powermanager shows that battery has a good state, there is no need to worry.
Well, I've even installed WinXP to check what than programm says, but as supposed it showed "good". I've tried to reboot battery(or something like that), but it was no good.

So, the question: is that normal or not? what's the problem?

Going next:
As I said before, new notebook's lifetime was about 2 hours(wifi is always turned on) and it's with 2800mAh battery(correct me)
But almost everywhere I've read about ~5-6 hours lifetime(in most reviews and markets at ru-net).
So, I don't belive that 5200mAh battery would save the day. Or am I wrong?
Because, I think it's time to buy a new one. And I'm a little bit confused; btw I don't want to buy extended battery for it's size.
Default 4cell makes X61s looks well as hi-teck black rectangle. But with extended one it's perfect shape becomes ruined. But if it would provide at least 4 hours lifetime, I would sacrifice my tastes and buy one.

Best wishes, Alex

Well the run time with an 8 cell battery is significantly increased..more than double. Mine gets over 2 hours on a charge but I am running windows XP.

Part of your problem may be that you are running an operating system that is not coupled with a lot of power management software, but I can't be sure.

8 cell is definitely worth it for the extra, but I agree that it is painful to destroy the profile of the laptop when it has a smaller battery. How often did you discharge the battery fully? That can significantly decrease battery life. Leaving it on and warm all the time also will decrease battery lifespan.

Hi there,

Most of the time laptop is lying on the table so only right bottom corner is warm(wifi module there) with closed lid.
Well, I've fully discharged it only a few times(not more than 10 I think). When it indicates critically low battery(less 4 minutes) I plug in adapter.
Powersaving is not fully tuned, but some tricks are.
So, using 8 cell battery gives you only 2 hours of working time with winxp? Or it gives you _plus_ two hours(getting ~4h. lifetime)?

Do the math:
The 4-cell cylindrical battery capacity = 37.44 Wh. An X61s with screen brightness at 5/7 and WiFi on consumes approx. 10W idle and 20W fully active.
- With a "duty cycle" of 1/3, the average wattage is approx 13W. Time on battery = 37.44Wh/13W = 2.88 hours.
- With heavier activity, say 2/3, one gets 37.44Wh/17W = 2.2 hours.

Everyone with an X61s and a good cylindrical 4-cell battery (i.e., full charge capacity = design capacity = 37.44Wh) will tell you that they get somewhere between 2 1/4 and 3 hours on that battery ... which is precisely what the math shows us.

Therefore:
- The 4-cell prismatic = 28.8Wh --> 1 3/4 - 2 1/4 hours.
- The 4-cell cylindrical = 37.44Wh --> 2 1/4 - 3 hours
- The 8-cell = 58Wh --> 3.5 - 4.5 hours.

If you adjust the brightness down a little, you can get 4+ hours from the 4-cell cylindrical battery, and it fits on the X61s identically to the slimline prismatic 4-cell battery, i.e., you do not deal with the ugly and heavy 8-cell battery.

Summary:
You have the prismatic 4-cell, which had low capacity even when new ... and now it has lost 1/3 of that capacity. Replace it with a new 4-cell cylindrical, and you will be very happy -- 3+ hours and no difference in size from what you have now!

EOMtp, thank you a lot for the math. And, could you please give me an article(?) number of the 4-cell cylindrical battery? Link to Ebay is ok too.
I just can't figure out with all these numbers >_<

Btw, I had played with some powersaving features on my ubuntu10.04 with the lowest screen brightness and got ~11.5-12W with opera and icq opened. 5/7 gives around 13.6W. So, EOMtp was right.
But, there is an issue with linux+intel 4965+power management. Looks like it wouldn't be fixed.
Anyway, thanks a lot for the help, guys.

The 4-cell "Enhanced" (i.e., cylindrical) battery is Part Number #40Y7001, which has many FRU #s (depending on manufacturer).
Be careful: Many sites on the Internet call ANY battery for the X6x/s by the number 40Y7001. Make sure it is the "enhanced" or "cylindrical" type. If you use the FRU#, then there is less chance of a "mistake", but even that is not guaranteed. You want for FRU #93P5028 or FRU #42T4570.

Below are a few links:
From Lenovo:
http://shop.lenovo.com/SEUILibrary/cont ... umber=7673

From Amazon.com (not OEM)
http://www.amazon.com/Battery-Lenovo-Th ... B002DUD502

This is the correct type, but who knows if it is OEM or no?! Probably not:
http://www.thinkpad-parts.com/92P1163-ThinkPad.html

Note: The battery "spacer" (for using the X61 batteries on the X61s) is FRU #42W3050. It should be included with a new battery. You can see it in the picture below:
http://public.bay.livefilestore.com/y1p ... 5989-8.jpg

hi there,

Just wanted to add some information.

voltage x Amp hour = watt hour

For the 8 cell X61s battery (not the tablet battery)

14.4V x 5.2 A = 74.88 Watt hours

If the X61s uses say 15 Watts per hour then it will amount to 75/15= 5 hours

If the X61s uses say 10 watts per hour then it will last for 7.5 hours

cheers,

Spacemonkey, you should be getting better life from the battery if you tune the power management properly. I run openSUSE 11.2 and get the same life out of a charge than I did running XP. My original 4 cell prismatic battery is now on it's last legs and only gives 45mins of charge but it's 3.5 years old. I have a 3.5 year old 8 cell battery and that still gives me 4+ ours of life on a charge. When new it gave me 7-8 hours with screen on 1/7 and very limited wifi - turn radios off when not being used. I could easily watch 3 full films on long haul flights and still have enough juice for a bit of web surfing at the airport. Screen brightness plays a large part of how long the charge lasts. If I need to eek out maximum life then I have the screen on 1/7 which can make it difficult if you're in a very bright room but most times it's ok.

It's also generally not good to have the battery sitting fully charged while the laptop is docked or on external power for long periods of time. Also you should avoid discharging the battery to zero or very close to zero. The best is to set the charge thresholds to start charging at ~55% and stop charging at ~70%. Don't run the battery down more than 15% before charging. Doing this will preserve the life of your battery. Obviously if you need to use your laptop away from power then fully charge it before going but try not to fully discharge it.

There is a kernel module for Linux called tp smapi that allows you to set the charging parameters of the battery. It allows a lot of configuration of the charge thresholds and other parameters and may already have been installed in Ubuntu (it's installed by default in openSUSE). Also, set your power manager to automatically reduce your screen brightness, switch the cpu to low power, etc when running on battery.

There is not much you can do with your current battery now as it's lost a lot of it's capacity but for the new battery it's worth spending a little time and getting your charging thresholds and power management properly set up to improve the battery performance and life.