My new T420's battery life

Hey guys,

I just received my T420 (with a 9-cell) today and I'm kind of concerned with the battery life. I charged the battery for about 6 hours before use, and when I powered it up, it says the estimated life is ~7 hours. This is at less than half brightness and in power saver mode.

Wasn't the battery life supposed to be in the 15hr zone? Am I supposed to charge the battery for more than I did?

 

Correct me if I'm wrong, but...

I believe battery life estimates are reactive, in the sense that they become more accurate after multiple discharge/recharge cycles.

 

You might want to try something like BatteryBar. It's much more real time than Power Manager's estimate.

 

1. While I always initially charge the battery for 12 hours before use (and most laptop manufacturers so advise), certain ThinkPad experts in this forum think and act otherwise. However, this is not a crucial point.

2. Keep on using the notebook. The "estimate" at "power up" is not an absolute. Throughout your session, the battery estimate (shown near the clock) will vary, depending on the workload -- and it can be longer than 7 hours.

3. Reality is reality.

 

Yea, I'm not exactly trusting the estimate it's giving me, but I thought it'd be somewhat in the ballpark. Either way, I'll just have to wait and see how long it actually lasts.

 

Keep us updated on your battery life!

 

Run a powercfg -energy diagnostic.

Avoid Chrome, Safari, and Opera. ( http://www.engadget.com/2011/03/29/ie9-is-the-most-energy-efficient-modern-browser-according-to-mi/)
Also avoid Skype and SRS HD Audio Labs (among others: find out using the above diagnostic under platform timer resolution).

Make sure your power options are set up optimally.

 

My T410s gets around 4-5 hours with a 9cell. The T420s is 30% more efficent, so you should be getting around 5.5-6.5 hours if you run with full brightness and a balanced profile. Run a few battery cycles though and give power manager some time to get a more accurate result.

Agreed. Use IE9.

 

Disagree. That testing does not show everything, and I would not trust results straight from microsoft. Chrome is a faster browser, so it may use more power by doing more work. The advantage of chrome is that even when you have lots of tabs open, and idle tabs will not eat up CPU time. I've experienced far better battery life with chrome than firefox. I can't speak for IE9, but IE8 feels sluggish to me.

cf. YouTube - Browser Test: Chrome 10 vs Firefox 4 vs Internet Explorer 9 vs Opera 11 vs Safari 5

Change the power manager settings to advanced and select power source optimized so that you have full power when you plug in and long battery life when on battery. Then, go through the settings and make sure the settings for battery are low. You should be able to get 2 dots for each parameter, maybe not for power usage. I recommend optical drive power off to be enabled. I recommend never stopping hard disk rotation, and the rest of the settings seem pretty clear what to set.

Also, part of getting good battery is having good user habits. Be sensible about heavy processor loads when on battery.

Also, if you've moved a lot of data from an old computer onto your new computer, the operating system will take a bit of time to index all the data for quick searching, which uses power. It should be done with a day. You can check it by pressing the start button and typing in index and choosing Indexing Options.

 

IE9 is essentially the fastest at SunSpider now. WAY faster than previous iterations. (although dubious)

I think the point of the results was that Chrome uses more resources than it needs to get the job done. Also, Chrome forces platform timer resolution to the lowest, which is a major drain on battery life. I also don't see any reason why idle tabs would eat CPU time in other browsers.

 

I mean, you can point to one benchmark, but in general, chrome is very fast, although the modern browser are all decent. IE9 vs Chrome 10 vs Firefox 4 vs Opera 11.01 vs Safari 5 - The BIG browser benchmark! | ZDNet

My experience with firefox before switching to chrome is that firefox often sits in the background, using 2-5% CPU power. Chrome does not do that for me, possibly because each tab gets its own process. Of course, this is merely my own personal experience. You can see I prefer chrome. In the end, seeing 7 hours versus say 12 or 13 hours is likely not due to browser choice.

By the way, what do you mean by powercfg -energy diagnostic?

 

Most of the browsers are about the same nowadays in terms of general usage.

My Firefox doesn't do that, except for when it spikes to automatically reload certain pages.

By powercfg -energy, I mean going to the command prompt and running the powercfg -energy command.

 

Ah before I tried typing "powercfg -energy diagnostic" I ran it plugged in. I noticed that it said firefox, itunes, and a svchost process were requesting that the platform timer or whatever be set to the min, but not chrome, which is open as well.

This is a cool tool. I'll try to run it when I get to be unplugged.

 

I think I spoke a bit too early, the battery life is better than I thought. I haven't run it for it's entire battery life, but at the current rate, I can see myself getting at least 10 hours. This is just an estimate, but I just wanted to say that I shouldn't have been worried about it and nor should you if you're considering one.

I really like my T420 so far and it's well worth the money.