Have I Killed My Battery?

I'm kind of confused and slightly worried. When I first got my laptop (T420 with a 9 cell battery) the power manager said I could get 6 hours on energy saver mode and 8 hours on maximum battery life mode. Now I get 4 hours on energy saver. I have only had the laptop for two weeks. Is this normal? because it seems like a large drop for such a small amount of time.

 

The first thing I would do is make sure nothing in the background in causing high CPU usage, etc. How is the health of the battery? Is it charging to it's capacity?

 

According to my CPU meter, it is below 10% usage right now. The power manager says the health of the battery is good, and I can charge it all the way to 100%.

 

Battery life changes may also be due to things like change in the cooling scheme, screen brightness, new BIOS, new hardware, peripherals, and many other things. I also noticed that the PM estimates are kind of erratic and deviate from those of Windows. I would actually use the laptop on battery and see how much you actually get.

 

No. It depends on what you do, and what Windows does behind the scenes, and a variety of settings. I find Power Manager's estimates to be fairly accurate.

 

i'm actually on going by percent now as the time estimate is so erratic. I feel it gives a better overall picture. The huge discrepency in estimates could just be due to what you were doing during or slightly before you saw it

 

I have been playing some games off of the battery lately, but now I just take it out and play solely off of the charger. I guess I should see how much time I actually get. Will do so as soon as I have some time.

 

Check the cycle count, last full capacity, and design capacity.

 

Cycle Count: 16
Full Charge Capacity: 93.69 Wh
Design Capacity: 93.96 Wh

Also, what should I set the charge thresholds to? The default is start below 96%, stop at 100%.

 

I don't know what's going on. Is it possible that the graphics card is stuck on? That would make sense of the battery life drop, but my GPU meter says it is at 0% usage.

One other thing I noticed is that the design voltage is 10.80 V, but mine uses 11.80 V.

And finally, I have never actually drained the battery fully. Should I do this so the battery knows its limits?

 

Do you have the NVS 4200M? If you do, turn off your GPU meter, because it is possible that it keeps the dGPU on by trying to get information from it. Either way, I'm pretty sure that you can get 7 ~ 8hrs out of a T420 with a 9 cell pretty easily as long as you are on the iGPU and not doing anything too intensive.

 

Yes, I was starting to think that might have done something. I'll try it and see what happens.

 

Success! As soon as I got rid of the GPU meter, the power manager estimate went up. I guess it makes sense, that in order for it to see how hard the GPU is working, it would need to have it on. Well, that problem is solved.

Thank you everyone who helped!

And just as a final thing to keep the battery good for a while, what is good setting for the charge thresholds?

 

I use 38% ~ 42%, and then take the battery out when it's at 42%. I don't suffer from throttling issues without the battery, though. So, if you do, don't take the battery out. Li-ion batteries like being around 40% from my internet research, so yeah. If you use the battery a lot though, I'd say something like 35% ~ 95% is good, or you can raise the minimum threshold if you don't use it for that long.

 

I've said this many times over the the owners thread, ANY performance monitors will negatively impact battery life. Every time you poll a device, it has to wake up to answer.

 

There's really no reason to take out the battery, I don't see what that's going to gain you.

In my humble opinion, I believe that if you use the battery daily for any significant period of time, you should just set it to always fully charge. Why? Because you bought the battery to use it, and it's by definition a disposable/replaceable item. Assuming you use it every day, I say, just use it and replace it when the time comes. It'll be money well spent. Now, if you don't use it on battery for a significant time every day, then I can understand utilizing these methods to extend it's life by a little bit.

One thing to keep in mind however is that there is no firm proof about how much you gain from these techniques. I've had thinkpads for a long time, and I've tried both keeping the battery at 40% and had some that I've always fully charged. My batteries have always lasted approximately the same amount of time. I correlate battery wear more with who manufactured your particular battery.

The Panasonic's have definitely lasted the longest for me. The Sanyo's almost always wear out very quickly.

So.... I'm just trying to offer a reality check. While these battery saving techniques do make a difference, in reality, it's hard to say if it's significant. And if you are a big battery user, I'd honestly say, just use it and replace it when the time comes. It'll make your life easier. It's tiring micro managing everything.

 

I leave my machine plugged in most of the time at the moment. I'll be carrying it around for university, though. I figured that since I don't have any problems running it without the battery, and that I don't need to use the battery, might as well as save it from some usage and heat. It is like literally 30C in my room these days, and if I use the battery, it can go up to around 38C or even higher, which isn't good. I believe I read somewhere that it is much better for the Li-ion cells to be charged to like 90 ~ 95% instead of 100% due to voltages or something.

 

Right, I wasn't trying to say not to do those things, or that they were meaningless. Just offering my perspective. I'd agree that if you hardly use the battery a partially discharged state (40%) is ideal.

 

I also have a T420, 9-cell, with the 4200M. What do you guys mean by turning off the GPU meter? Is that simply the nVidia activity monitor that runs in the system tray (the one that tells you of any programs using the nVidia GPU)?

 

Oh, the GPU meter was this desktop gadget I downloaded. Here: Windows Live Gallery

Now, I have one more question. When I have my laptop on AC but it is not yet below the charge threshold, the battery does not seem to go down. What is happening?

 

When your battery is in between the charging percentages you have selected in Lenovo Power Manager (i.e. your thresholds are 40/85 and your battery is at 50), your battery is maintained at the current percentage and your laptop runs off AC mode.

 

Yep, what ktang said. The laptop draws power from AC and leaves the battery alone at whatever percentage it's at.

 

Oh, that's pretty neat. Is there any way to get it to charge when in in between the charge thresholds (other than disabling those)?

 

You'd have to change the charge thresholds to get it under the begin to charge number.