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Studying the Slow Decay of a Laptop Battery For an Entire Year
First time accepted submitter jradavenport writes "I've been keeping a log of the health of my MacBook Air battery for the past year, taking samples every minute I use the computer (152,411 readings so far!). This has allowed me to study both my own computing/work habits, but also the fascinating rapid decay of battery capacity. Comparing it to my previous 2009 MacBook Pro, the battery in this 2012 Air is degrading much faster."
I got 10 hours of battery life on my 2011 macbook air when I first got it. I don't just mean 10 hours of it sitting idle either. I could get 7 hours of continuous play of movies. Then Mountain Lion came out and I was lucky to get 3 hours tops. That lasted 6 months until they "fixed" it and I was able to get 5 again. Now in I can consistently get 4 hours with it sitting mostly idle.
I love the machine but I hate that I cant change the battery myself. I'll have to pay the Apple tax to get this fixed. I am holding out hope for Mavericks though, hopefully the power saving features can breathe some new life into this thing.
We live with what we got now. That is life. But ...
Within a few years that will change with lithium-sulfur batteries if the lab geeks have anything to say about it.
http://www.extremetech.com/extreme/157525-new-sulfur-based-battery-is-safer-cheaper-more-powerful-than-lithium-ion
Most modern lithium batteries should *not* be cycled or discharged "fully"--such a practice degrades the battery capacity quite rapidly. I think the practice of fully discharging the battery comes from the NiMH-type rechargeable AA(A) batteries.
Yeah, sometimes people recommend fully discharging a lithium battery during operation so that the monitoring software can recalibrate it's battery power meter to adjust for the decline in total capacity, but I'm not sure it's worth it.
As mentioned earlier, temperature is a big factor as well. Maybe Haswell will save the day...
You have to do that every once in awhile if you want the battery status indicator to be correct. This is because the voltage curve is so flat there really is no other way to determine level of charge other than to count power out and calibrate what the battery should hold periodically.
Bad batteries something Apple is famous for, RAM fixed to the logic board, insecure and buggy OS, and a host of other complaints makes me wonder why anyone pays the premium for Apple any longer.
Maybe because that hasn't been most peoples' experience? I have a MacBook Pro that is almost 3 years old and the battery is still almost as good as the day I bought it. Of course, I make sure to run mine down once a month as recommended.
Taking guns away from the 99% gives the 1% 100% of the power.
Because of the whole host of other problems with that suggestion.
Here is a small set of them, there are many more
1. expensive fuel cell
2. low density storage unless you go with expensive metal hydrides
3. H2 embrittles everything
4. far cheaper to make H2 via steam reformation of natural gas than electrolysis
I love studies with a sample size of one. No statistics, no variability. Definitive.
Almost every iPhone on record has been more likely to shatter its screen than the one before it. Apple went from 1st in lowest malfunction rates to 6th from 2007 to 2011. The new ipad is heavier, runs hotter, and gets worse battery life than the one before it. This isn't exactly a new pattern that the battery in the new air is inferior. Everything Apple is going downhill.
PROTIP: MacBook Air batteries aren't removable (in that sense).
www.clarke.ca
I was thinking about it more during lunch. It's not just a battery test which occurs every minute, it's the entire script he wrote, including the testing and the subsequent appending of that data to a file. That could amount to a significant number of drive accesses which normally wouldn't have happened, especially at night when it would have otherwise been idle.
Though, to be honest, I've rarely ever installed additional RAM in any PC I had - given its cost, it's usually cheaper to buy the max up front than in a few years when memory standards change and it's difficult to buy it cheaply (e.g., DDR or DDR2) - especially the larger modules - they either simply stop existing or are still wildly expensive years later.
I've never bought a Mac with RAM fixed to the logic board; and with pretty much every Mac I've ever bought, I've bought it with the minimum RAM configuration and then gone third party to top it up either immediately or within 2 years -- usually saving a few hundred dollars. The one thing Apple IS known for is overcharging for RAM. They've always done this, even back in the SIMM days. They argue that it's because they have higher standards, and thus you're only getting the best RAM from them. I've NEVER had a problem with using properly sourced cheaper RAM with a Mac.
PROTIP: Remove your laptop battery if you are running from the mains most of the time and keep it in a cool drawer somewhere.
MacTip: DON'T. Your Mac automatically scales back its clock speed to 1 GHz tops. Brownouts can crash your computer immediately because there is no battery to supply power. Magsafe connectors and no battery are an obvious bad combination. And you'll get dust into your computer.
If you don't care if the battery gauge is inaccurate, you should never cycle the battery completely. Lithiums thrive with frequent top-ups.
Unfortunately, having a useful gauge is handy so it's useful to cycle the battery occasionally.
I rarely use battery power deep into a battery's cycle so I don't worry too much about it.
While a bearing failing out of the blue for something like a cam or crank shaft it is exceedingly rare if they kept oil in the car stuff like water pumps, and alternators are basically consumables and just wear out and aren't too expensive to have replaced. I also get your point about people unnecessarily beating on their vehicles I see the same things. The one that gets me is when the engine first catches it's like they are in a drag race out of their parking spot, let the engine run for a couple of seconds and build oil pressure. My point was that most people should realize that it is much cheaper to maintain your vehicle than it is to replace it and that little problems like little squeaks, rattles, and squeals are a lot cheaper to fix than when what ever was rattling, squealing, or squeaking fails in a catastrophic manner.
For example if a wheel is making noise have it checked either by a shop or your self if you know what to look for and make the noise go away:
It might be the pad wear indicator just starting to scrape (replace the brake pads and enjoy your new found stopping power) It might be that you have run the pad backing into the rotor in which case you avoided a very bad problem but you might need you hearing checked since it got this far
The bearing might just be a little dry in which case greasing it solves the problem
If the bearing is completely dry you just avoided a very bad problem
If the needle bearings are gone you just avoid a very bad problem but why did you wait so long as it should have been making nose for a while so go get your hearing checked
Time to offend someone