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Ask HN: Should I unplug my laptop charger at 100%?

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Re: Ask HN: Should I unplug my laptop charger at 100%?

#13

Post by toxicFork »

jerf wrote: post #8

As I sit and look at the replies already coming in, may I just add an enormous [citation needed] to the entire discussion? A question brought on by too many conflicting anecdotes can not be resolved by throwing another unsourced anecdote on the pile. (Incidentally, I'm at least a bit curious myself as to the answer, and have my own pile of conflicting anecdotes I've read.)

This is my favorite technology superstition, some citation would help many people sleep easier it seems.

Re: Ask HN: Should I unplug my laptop charger at 100%?

#15

Post by mwexler »

ars wrote: post #5
rajeshmr wrote: post #3

AFAIK only macbooks have been designed to bypass battery ( once the charge is 100% ) and directly run on connected power. For other notebooks its best to unplug charger at 100% and connect charger at around 10% to get a longer lifetime of the battery.

Not 10%! That's terrible for a Lithium battery. Charge it when it gets to 40%.

Ah, so I can only use 60% of my battery before I have to find a plug? Bummer.

Re: Ask HN: Should I unplug my laptop charger at 100%?

#17

Post by solve »

You should have talked to Google, instead of numerous people.

http://batteryuniversity.com/learn/article/how_to_prolong_li...

Summary:

Similar to a mechanical device that wears out faster with heavy use, so also does the depth of discharge (DoD) determine the cycle count. The shorter the discharge (low DoD), the longer the battery will last. If at all possible, avoid full discharges and charge the battery more often between uses. Partial discharge on Li-ion is fine. There is no memory and the battery does not need periodic full discharge cycles to prolong life.

To answer your question: No.

Side note: Don't blindly trust the manufacturer. Of course Apple wants you to wear out your laptop as fast as possible, once it's past the warranty. They're a business.

Side note 2: Laptops do NOT charge your battery to 100%. Your battery indicator is fake. 100% on your battery indicator is more like 90% in reality. The charger automatically cuts off before it reaches the true 100%, so all of the comments in this thread about 100% being bad are wrong, because no modern laptops will truly let you reach 100%.

Re: Ask HN: Should I unplug my laptop charger at 100%?

#18

Post by paulannesley »

> For proper maintenance of a lithium-based battery, it’s important to keep the electrons in it moving occasionally. Apple does not recommend leaving your portable plugged in all the time. An ideal use would be a commuter who uses her notebook on the train, then plugs it in at the office to charge. This keeps the battery juices flowing. If on the other hand, you use a desktop computer at work, and save a notebook for infrequent travel, Apple recommends charging and discharging its battery at least once per month.

— https://web.archive.org/web/20110521104819/http://www.apple.... via http://apple.stackexchange.com/a/12280

This could also be useful, but doesn't answer the question directly: http://www.apple.com/batteries/maximizing-performance/

Re: Ask HN: Should I unplug my laptop charger at 100%?

#20

Post by tdkl »

cjbprime wrote: post #2

No. Your battery degrades each time there's a cycle of charge->use. If you're lucky, you can do that a few thousand times before you lose much of your battery's capacity. If you leave it plugged in, you aren't losing cycles, so you should do that.

> If you leave it plugged in, you aren't losing cycles

Too bad that some batteries wear out even faster this way because of the heat.

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