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The De-evolution of My Laptop Battery

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Re: The De-evolution of My Laptop Battery

#81

Post by wikwocket »

theGimp wrote: post #54
wikwocket wrote: post #31

Earlier quoted context omitted.

I wonder if using your laptop plugged in at your desk 90% of the time, but carrying it around to use in meetings the other 10%, is as good as their "ideal use."

Maximizing your battery's life is not remotely close to a science, but as a rule of thumb, discharge to 50% every couple of days then recharge.

Well as long as there continue to be long, drawn-out, rambling meetings, we're good to go! Although in that case, a short battery life is a feature: "Oops, I'm at 5%! Be right back while I fetch my charger!"

Re: The De-evolution of My Laptop Battery

#82

Post by JimmaDaRustla »

thehme wrote: post #74
JimmaDaRustla wrote: post #64

WHOA!! Huge mistake here - he says he cycles his battery! DO NOT DO THIS TO LITHIUM ION BATTERIES! Lithium Ion will last longer by NOT allowing the cells to be fully discharged! This is the opposite of Nickel Metal Hydride and Nickel Cadmium - these types of batteries DO require a full discharge and full recharge in order to provide a longer life. In addition, the number of discharges, the temperature, etc all come i…

I believe you are correct on the "cycling the battery", which I believe you want to avoid, so that you battery will be able to charge fully for longer. "A charge cycle means using all of the battery’s power, but that doesn’t necessarily mean a single charge. For instance, you could listen to your iPod for a few hours one day, using half its power, and then recharge it fully. If you did the same thing the next day, it…

There are mixed meanings in the definition of "cycle", but both make sense, just depends on the context. Thanks for the blurb!

He does state "letting the battery" cycle, so I'm assuming he is implying the battery is being allowed to be discharged near fully.

Re: The De-evolution of My Laptop Battery

#83

Post by mistercow »

JimmaDaRustla wrote: post #64

WHOA!! Huge mistake here - he says he cycles his battery! DO NOT DO THIS TO LITHIUM ION BATTERIES! Lithium Ion will last longer by NOT allowing the cells to be fully discharged! This is the opposite of Nickel Metal Hydride and Nickel Cadmium - these types of batteries DO require a full discharge and full recharge in order to provide a longer life. In addition, the number of discharges, the temperature, etc all come i…

The really dumb thing is that, as far as I can tell, a battery's controller generally counts a "cycle" as "started discharging, started charging", regardless of time in between. At least, that's how it was with my MacBook a few years ago. Unplug, plug in, cycle count increases.

The crappy thing about that is warranties. Apple, for example (at least last I checked; I don't use a Mac anymore) , would replace a battery if it had under some number of charge cycles (and presumably was less than a year old), but not if it had more than that number.

That means that if you treat your battery really nicely by always keeping its charge between 40% and 60%, and it turns out to be defective, they probably won't replace it because of how many "cycles" it has gone through.

Of course, those kinds of cycles have very little to do with the longevity of a Li+ or LiPo battery anyway. A better metric would be total energy output over time, which would be far simpler to calculate anyway.

Re: The De-evolution of My Laptop Battery

#84

Post by tomkarlo »

gz5 wrote: post #78
tomkarlo wrote: post #53

Earlier quoted context omitted.

Can you point to data showing competitors that are doing it better? Seems like the battery life problem impacts everyone pretty equally, and the batteries being used inside Macbooks are pretty similar to those used by every other manufacturer.

agree, this is not specific to macbooks. bottom line is today's batteries only achieve (relatively) limited charge/discharge cycles and i don't believe (could certainly be wrong) there is much business motivation to improve that.

I'm sure manufacturers keep an eye on some minimum standards for battery life over product life - they do have a financial incentive to do so, both from a brand quality perspective and in terms of the cost of each visit to the Genius Bar / warranty claim. I replaced the battery on my MacBook twice under warranty, I can't imagine that laptop ended up being profitable for Apple.

Re: The De-evolution of My Laptop Battery

#85

Post by rocky1138 »

driverdan wrote: post #42
sixothree wrote: post #20

Is this guy really a developer? I can't imagine using a single 15" monitor to accomplish anything at a productive pace.

I used 2+ monitors from 2000 to 2010ish. After switching to only laptops I gave up secondary displays and never went back. The only times I miss it is when I want to have docs open. I don't know why you'd need it otherwise.

Same. I made the switch when KDE started supporting the Ctrl+Alt+Arrow Keys to spin my desktop around on a six-sided cube. So much handier to flip between sides. I really miss that in Windows.

Re: The De-evolution of My Laptop Battery

#86

Post by npsimons »

JimmaDaRustla wrote: post #64

WHOA!! Huge mistake here - he says he cycles his battery! DO NOT DO THIS TO LITHIUM ION BATTERIES! Lithium Ion will last longer by NOT allowing the cells to be fully discharged! This is the opposite of Nickel Metal Hydride and Nickel Cadmium - these types of batteries DO require a full discharge and full recharge in order to provide a longer life. In addition, the number of discharges, the temperature, etc all come i…

Interesting. Last I looked, the supposed optimal way to prolong a Li-Ion battery was to not let it get below 50% (ie, plug it in to charge when it gets to 50%). I think it was from a link off of Lifehacker a while back. Storing at 40-60% was recommended as well.

I do typically use a smart charger on my NiMHs, and make sure to "break-in" (full discharge -> trickle charge to full -> full discharge -> trickle charge to full) every three months (12 for the new LSDs); I've managed to keep some AAs for well over a decade doing that, albeit I have plenty of spares, so I cycle through them and most are kept at room temperature storage. I used to freeze, but read that that might not be good for them long term (not to mention you have to wait for them to warm up before you can swap, defeating the purpose of spares; also, there's the possibility of thermal shock if you don't warm them up slowly/gently in the fridge).

Re: The De-evolution of My Laptop Battery

#87

Post by jaggederest »

untothebreach wrote: post #32
aeturnum wrote: post #16

Earlier quoted context omitted.

I had my first macbook's battery replaced. I took it into the apple store for an unrelated problem, the tech noted the awful battery life and asked me how old the laptop was, said, "that's not right...," and grabbed another battery. Nice and easy.

If I remember correctly, with the Macbook Air it will have to be '"that's not right...", and grabbed another Macbook Air, and started migrating my data, etc, etc...'

They're just held in with torx screws, from what I could see of my old 'unibody' mac when I took it apart. Current gen may be different though.

Re: The De-evolution of My Laptop Battery

#88

Post by Scaevolus »

jbert wrote: post #17
netcraft wrote: post #9

anyone know how to do something similar on a windows laptop?

I'd guess: - write a little code to drive this API: http://stackoverflow.com/questions/7785096/read-laptop-batte... - and either use a task scheduler to run your code every minute, or startup a long-lived process which just does this and sleeps - output in whatever format you like. CSV is obviously good, but given richer APIs on windows you could dump it straight into an excel sheet I guess.

RRDTool is great for storing these sorts of time-series archives, and it will generate pretty graphs as well. You could cobble together an app starting from these StackOverflow postings:

Task Scheduling: http://stackoverflow.com/a/2725908

RRD interface: https://pypi.python.org/pypi/PyRRD

Battery reading: http://stackoverflow.com/a/6156606

Re: The De-evolution of My Laptop Battery

#89

Post by jacquesm »

JimmaDaRustla wrote: post #64

WHOA!! Huge mistake here - he says he cycles his battery! DO NOT DO THIS TO LITHIUM ION BATTERIES! Lithium Ion will last longer by NOT allowing the cells to be fully discharged! This is the opposite of Nickel Metal Hydride and Nickel Cadmium - these types of batteries DO require a full discharge and full recharge in order to provide a longer life. In addition, the number of discharges, the temperature, etc all come i…

As they say in the renewable energy field: the majority of batteries do not die peacefully, they are murdered.

As a bit of a re-assurance, the typical laptop power circuit in a laptop using lipo is aware of this and will simply refuse to drop the battery below a certain level so likely the damage is somewhat limited. Still, if you don't need to discharge a battery all the way as far as the circuitry will let you with lipo's you'd better not.

Re: The De-evolution of My Laptop Battery

#90

Post by jordanb »

JimmaDaRustla wrote: post #64

WHOA!! Huge mistake here - he says he cycles his battery! DO NOT DO THIS TO LITHIUM ION BATTERIES! Lithium Ion will last longer by NOT allowing the cells to be fully discharged! This is the opposite of Nickel Metal Hydride and Nickel Cadmium - these types of batteries DO require a full discharge and full recharge in order to provide a longer life. In addition, the number of discharges, the temperature, etc all come i…

> opposite of Nickel Metal Hydride

Fully discharging any battery isn't good for it. NiCd had the particular problem of "memory" developing though, so going through a full discharge cycle was necessary to prevent the memory forming. It wasn't good for the battery, but it was better than letting the memory develop.

I'm not aware of NiMH developing a memory, so that wouldn't be a good thing to do with NiMH either. I always tried to avoid full discharge of my NiMH batteries and always got a pretty long life out of them.

Really the full discharge cycle is an artifact of the needs of one particular chemistry (NiCd) that became something that "everybody knows" you should do long after it became counterproductive.

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