Thinkpads Forum

My battery feels like it's getting tired. I ran TP SMAPI and it is telling me that the battery has 202 cycles on it. Is it time for a replacement? The machine is about 2 years old.

I am running Ubuntu 12.04 and I know that it will give me less life than Windows would, but just wanted to feedback on battery health indicators...

Usually a battery lasts for many years but it's usable life depends on what you expect. There is a common problem with batteries that's called "jumping". It means that the battery seems to be working normally and out of nowhere, it goes close to zero. This usually happens when one of the cells inside the battery pack starts failing but the controller fails to compensate for it.

If your battery discharges normally to zero then it's just a matter of finding if the capacity is acceptable to you. If not, you can buy a new one and keep the old as a backup.

If the battery "jumps" it's time to change it as the operating time becomes pretty much unpredictable...

kennyschiff wrote:the battery has 202 cycles on it. Is it time for a replacement? The machine is about 2 years old.

Around 200 cycles is a good service life for a LiOn battery. Whether it needs to be replaced will depend on its exact overall condition, which is

In general, the OS you run shouldn't have much impact on battery life per se, but the degree of sophistication in battery management available in the OS might.

Cheers,

Bill B.

What's a good way to determine condition? especially if one is not running Windows?

Test it like I said:

1) Charge it fully.
2) Let the machine discharge and watch it the entire time, it should discharge gradually when sitting idle without "jumping". If it jumps, then the battery needs to be replaced.
3) Let it discharge completelly disabling alarms (hibernation, etc).
4) Charge it fully.

At this point it should be recalibrated and the condition of the battery should depend entirely on the remaining capacity. I'd say, if you depend heavily on battery, around 70% of the original capacity is the minimum. Below that is time to replace it. If not that important, probably up to 50%.

For example, I had an X300 and it reported 33Wh out of 43Wh of design capacity so around 70%. But it didn't hold the charge and sometimes it even jumped so I had to replace the battery.

Not sure about the X201, but the latest linux kernels (3.6.x) are killing battery life for a lot of people. I notice my laptop (X220) oftentimes running much hotter under linux with the 3.6.x kernels.

GomJabbar wrote:Not sure about the X201, but the latest linux kernels (3.6.x) are killing battery life for a lot of people. I notice my laptop (X220) oftentimes running much hotter under linux with the 3.6.x kernels.

I can second this, I've Linux for a long time but I've personally never found the power management to be as good as Windows. Lenovo's power management software is actually quite good.

202 cycles is a good amount, but I've seen a pretty wide spread of run time on batteries with similar cycle counts. Some are down to 50% original capacity, others are still going strong. I have a 6 cell battery for my X200s with a little over 200 cycles and it still gives me nearly 5 hours (with conservative use).

If you could get access to Windows you can do a full battery reset in power manager and it will give you the exact current Wh/original Wh.

Unfortunatlely, while I do have a proper Windows COA, I don't have Windows on my hard disk. Is there a way to do the reset w/o having Windows installed?

Leave the machine on until shutdown due to low battery. Turn machine back on and load into BIOS. At the BIOS welcome screen, let the machine idle until it powers off due to low battery. As soon as the laptop powers off from the BIOS screen, recharge it and let it fully charge.

Just don't leave the battery fully drained for long or it may get damaged.

Resetting the battery by a full discharge/recharge has never seemed to increase the battery life much on my machines - only to perhaps make the remaining battery life indicator a little more accurate.

What does help is to set the charging thresholds to a lower value. I have mine set to start charging at 85% and stop charging at 90% (with Power Manager in Windows). This does seem to extend the overall battery life by months or years.

Currently, on my X220, which is 1-1/2 years old, I have a 6-cell battery. Here is what Power Manager shows. Admittedly, I use my laptop mostly plugged in, but I do use the battery on occasion.

I set it to 50/80. I've read that charging the battery to 90% gives you 50% more useful life. Charging it to 80% triples it...

I bought a new battery, and also set up tp-smapi to limited charging per the various instructions detailed here...

I have not fired up new battery yet, but I've discharged and charged my original, with the adjusted charging thresholds... It will be interesting to see what effect this has. I've also installed laptop-mode-tools.