5 ms·

Pull the plug. Your battery will thank you

91 points by dmlorenzetti 17y ago

sailormoon 17y ago
I killed 2 macbook pro batteries in 2 years by not following this advice. Now I make sure to unplug and carrying around the laptop whenever I can. Eliminating all wired peripherals was a key step to actually doing this in practise.
- lutorm 17y ago
  I thought the MBP battery switched off charging when it was full, so that it charges up the battery and then disconnects it if you are plugged in. When the battery has self-discharged some amount, it tops it up again. But maybe I misunderstood. The flipside, though, is that Li-ion batteries also age from discharge cycles. So I really don't think it's better to run the battery down, charge it up, and repeat. The number of charge cycles is limited, so I bet that will kill it faster. If you really want to save the battery, you can take it out and put it in the fridge when you are plugged in.
  - jonknee 17y ago
    > If you really want to save the battery, you can take it out and put it in the fridge when you are plugged in. Unfortunately MacBook Pro batteries are not removable anymore. That really grinds my gears.
    - moe 17y ago
      Well, technically you can and it doesn't look too hard: http://www.youtube.com/watch?v=42qcvlftmcM http://www.youtube.com/watch?v=42qcvlftmcM But it seems apple is not officially selling those batteries, which makes my gears grind. I don't want to walk to an apple store or send my laptop away just to have the batter swapped.
  - mcculley 17y ago
    Yes, you are correct: http://support.apple.com/kb/TS1909 http://support.apple.com/kb/TS1909 At least, that is the way it is supposed to work. I've been through a few batteries that were replaced under warranty free of charge by Apple for premature failure. I've noticed that one of my 4 MagSafe chargers is not charging correctly any more even though it can power the computer just fine. It took me a while to figure out that was the case as I kept incorrectly concluding that the problem was in the battery. There have been reported problems with the chargers failing in this way. I think that because a modern laptop can now have intelligence in the charger, the battery itself, and the power management functions of the laptop, we are seeing problems that are hard to debug.
- chrisolsen 17y ago
  I have also gone through 2 batteries in just over 2 years. The first was fully recharged quite a bit seeing as I was always working remotely. The second battery went through much fewer charge cycles since I was working from home and I was making attempts at improving the life of the second. Each of the batteries I purchased died out at about the same time. Unless I got two bad ones, it seems to me that mac batteries weren't of the best quality during the time of my purchases.
DanielStraight 17y ago
I always knew you shouldn't leave your laptop plugged in all the time, but I never really knew why, and my subtle misunderstanding was actually harmful. I thought the issue was just that sometimes you needed to let the battery drain and recharge it from a drained state. That's not very helpful though if the rest of the time you're running at full voltage. Thank you for the submission. Great article.
arghnoname 17y ago
I have a Lenovo laptop and it has the feature it describes. You can set a manual charge cut off or do the following: "Optimize battery lifespan (automatically change for me)" Right now, it seems to not charge the battery unless it gets under 96% charge, and then it charges to full. Its language implies that it changes that charge level based off of a good compromise between battery life and charge. As someone who doesn't want to think about the battery issue, I really love this feature.
- pmjordan 17y ago
  Macbooks do the same, but I haven't found a way to change the threshold. 90, 85 or even 80% would be fine for me.
lftl 17y ago
Interesting... sounds like an interesting application for this idea: http://www.unplggd.com/unplggd/green-ideas/leech-plug-unplugs-itself-after-it-completes-a-charge-108847 http://www.unplggd.com/unplggd/green-ideas/leech-plug-unplug...
davidw 17y ago
Huh... that's annoying. 95% of the time, I use the laptop in my home office and don't really want to mess around with plugging/unplugging it:-/
- marcusbooster 17y ago
  What about running it through a 6 outlet switch that you can readily turn on/off?
  - davidw 17y ago
    The problem is that I shouldn't have to do anything. The computer should be able to figure this stuff on its own - after all, that's the kind of task that they're good for.
    - FlorinAndrei 17y ago
      Oh, the "computer" (read: the manufacturer) has it all figured out already, rest assured. They just don't want to give up on a few performance percentage points.
      - psadauskas 17y ago
        Or, more likely, selling you replacement batteries.
        davidw 17y ago
        Ok, but at the same time, they could also tack some money on to the price for "batter life extending technology" and make money that way...
- yungchin 17y ago
  For desk use, it's best for your battery to remove it from the laptop once it's fully charged. You don't want to continuously plug/unplug your laptop because that would just cycle the battery a lot, and that's not good for it either. As for me, I usually just leave the battery in: it's a nice UPS, worth the expense of perhaps a few months of lost life.
niyazpk 17y ago
Where I stay in Bangalore, we have about 3 one hour power cuts per day. So my laptop battery is getting good exercise!
nazgulnarsil 17y ago
simpler solution than constant plugging and replugging for me was to remove the battery if I'm not going to be moving the laptop for an extended period.
- chops 17y ago
  It's nice having that battery as a UPS though, in the event of an outage.
mustpax 17y ago
So, why don't laptops completely bypass the battery when the battery is charged and the power is plugged in? If the laptop can work when the batteries are removed, it should be able to cut-off power to/from the battery when fully charged as well.
- rdtsc 17y ago
  When the laptop is at home, just charge the battery to 50% then remove it so it works only from the plug. I don't move my laptop as much as I did before and I noticed that I get much better battery lives than my friends who continuously keep their laptop plugged in and with the battery attached.
  - mustpax 17y ago
    Obviously this is the current solution. I was pointing out that laptop manufacturers could remove the need for fiddling with your power connection by automatically disconnecting the computer from the battery when it is not needed.
    - eru 17y ago
      Yes, but you need a way to tell it whether you don't want to use the battery in a long time (so 50% charge is good), or whether you want to get up and go on the road soon --- where 100% charging is nice.
      - rdtsc 17y ago
        Allegedly Thinkpads have that. But I run Ubuntu on mine so I don't have access to the fancy bios setting utilities from Lenovo. I just snap the battery out. That seems to work for me.
BigZaphod 17y ago
I've had Apple laptops going back to the release of the Titanium PowerBook and I've almost always used them plugged in for the vast majority of the time and I've never had this dreaded battery death that articles like this talk about. However, I have a friend who seems especially apt at killing the very same batteries in the very same laptop models. My rather uninformed theory is that there's a specific kind of behavior that adversely affects them - but whatever it is, I don't do it and he does. I think the key is that he uses his without power a lot, running it down frequently, etc. which seems to be what this article is suggesting (and most articles about prolonging battery life suggest). Given my own experience, I'm continuously confused at the pervasiveness of this advice given how counter it is to my own experience - but perhaps there's some intelligence in the batteries/charger that's protecting me from myself? I mostly think of my battery as a built in UPS and not as a gas tank.
- FlorinAndrei 17y ago
  Right. So, don't run it down a lot, and don't charge it to 100% unless you have to.
- nasalter 17y ago
  FYI, Apple have a page providing advice on battery care: http://www.apple.com/batteries/ http://www.apple.com/batteries/ One of the things it says is... "Standard Maintenance 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 MacBook Pro 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."
  - jrockway 17y ago
    For proper maintenance of a lithium-based battery, it’s important to keep the electrons in it moving occasionally." I knew I shouldn't have set my air conditioner to absolute zero...
Zak 17y ago
The article mentions that Thinkpads come with a utility to set the charging cutoff point. Has anybody figured out how to do this on Linux?
- yungchin 17y ago
  http://www.thinkwiki.org/wiki/Tp_smapi#Battery_charge_control_features http://www.thinkwiki.org/wiki/Tp_smapi#Battery_charge_contro...
- sandGorgon 17y ago
  bug filed - https://bugs.launchpad.net/ubuntu/+source/gnome-power-manager/+bug/428543 https://bugs.launchpad.net/ubuntu/+source/gnome-power-manage...
yungchin 17y ago
The article is right, but it's hard to read. If you don't read carefully, it seems to suggest cycling your battery more, when actually it just suggests not pushing it near 100% charge too long. Here's a complete and simple summary of good practice: http://batteryuniversity.com/partone-21.htm http://batteryuniversity.com/partone-21.htm (more details on other parts of that website) - for most geek-apparel, the LiIon column will be applicable.
jockc 17y ago
Seems like it would be easy for laptop makers to design something into the laptop to manage how the battery charges/discharges when it's plugged in. That way you could leave it plugged in 99% of the time (as probably many of us do) and not impact the battery negatively.
ANH 17y ago
Over the past four weeks my Macbook Pro battery's performance declined precipitously, and I think this is the cause. I tended to leave it plugged in whenever I was at my desk, which is most of the time. Got to the point where the MBP wouldn't last more than 5 minutes unplugged. Just received a new battery and all is well. Think I'll be giving this technique a shot.
sounddust 17y ago
Newer Sony laptops come with "Battery Care" software that automatically keeps the battery between 50 and 80% at all times. According to Sony engineers, a battery that is always kept at or below 50% will essentially never degrade in capacity.
- there 17y ago
  so what's the point of having a big battery then if it never charges to 100%?
  - sounddust 17y ago
    Well, it's still more battery life than a small battery that never charges to 100%, right? I think regardless of the battery size, you can make the decision to preserve the long-term life of your battery or have the extra capacity in the short-term. Plus, charging from 20 to 80% is much faster than charging from 20 to 100% (I estimate that about half of the time is spent just going from 80 to 100).
bonsaitree 17y ago
While correct, I really view this as a non-issue. I suspect for most people, their in-memory data, time, and attention are far more valuable than not having power redundancy protection against an accidental cord disconnect or possible increased degradation on a ~$100 replaceable component on a $1k+ machine--namely the battery.
GeneralMaximus 17y ago
I've had my MacBook for 1.5 years now, and my battery life is still a little more than 4 hours. I keep my machine plugged in all the time, and completely run it down once a month. On the other hand, my friends who have the same MacBook have terrible battery lives. They use the laptop on batteries all the time. I'm inclined to believe this guy has no idea what he's talking about.

91 points by dmlorenzetti 17y ago

I killed 2 macbook pro batteries in 2 years by not following this advice. Now I make sure to unplug and carrying around the laptop whenever I can. Eliminating all wired peripherals was a key step to actually doing this in practise.

lutorm 17y ago
I thought the MBP battery switched off charging when it was full, so that it charges up the battery and then disconnects it if you are plugged in. When the battery has self-discharged some amount, it tops it up again. But maybe I misunderstood. The flipside, though, is that Li-ion batteries also age from discharge cycles. So I really don't think it's better to run the battery down, charge it up, and repeat. The number of charge cycles is limited, so I bet that will kill it faster. If you really want to save the battery, you can take it out and put it in the fridge when you are plugged in.
- jonknee 17y ago
  > If you really want to save the battery, you can take it out and put it in the fridge when you are plugged in. Unfortunately MacBook Pro batteries are not removable anymore. That really grinds my gears.
  - moe 17y ago
    Well, technically you can and it doesn't look too hard: http://www.youtube.com/watch?v=42qcvlftmcM http://www.youtube.com/watch?v=42qcvlftmcM But it seems apple is not officially selling those batteries, which makes my gears grind. I don't want to walk to an apple store or send my laptop away just to have the batter swapped.
- mcculley 17y ago
  Yes, you are correct: http://support.apple.com/kb/TS1909 http://support.apple.com/kb/TS1909 At least, that is the way it is supposed to work. I've been through a few batteries that were replaced under warranty free of charge by Apple for premature failure. I've noticed that one of my 4 MagSafe chargers is not charging correctly any more even though it can power the computer just fine. It took me a while to figure out that was the case as I kept incorrectly concluding that the problem was in the battery. There have been reported problems with the chargers failing in this way. I think that because a modern laptop can now have intelligence in the charger, the battery itself, and the power management functions of the laptop, we are seeing problems that are hard to debug.
chrisolsen 17y ago
I have also gone through 2 batteries in just over 2 years. The first was fully recharged quite a bit seeing as I was always working remotely. The second battery went through much fewer charge cycles since I was working from home and I was making attempts at improving the life of the second. Each of the batteries I purchased died out at about the same time. Unless I got two bad ones, it seems to me that mac batteries weren't of the best quality during the time of my purchases.

DanielStraight 17y ago

I always knew you shouldn't leave your laptop plugged in all the time, but I never really knew why, and my subtle misunderstanding was actually harmful. I thought the issue was just that sometimes you needed to let the battery drain and recharge it from a drained state. That's not very helpful though if the rest of the time you're running at full voltage. Thank you for the submission. Great article.

arghnoname 17y ago

I have a Lenovo laptop and it has the feature it describes. You can set a manual charge cut off or do the following: "Optimize battery lifespan (automatically change for me)" Right now, it seems to not charge the battery unless it gets under 96% charge, and then it charges to full. Its language implies that it changes that charge level based off of a good compromise between battery life and charge. As someone who doesn't want to think about the battery issue, I really love this feature.

pmjordan 17y ago
Macbooks do the same, but I haven't found a way to change the threshold. 90, 85 or even 80% would be fine for me.

lftl 17y ago

Interesting... sounds like an interesting application for this idea: http://www.unplggd.com/unplggd/green-ideas/leech-plug-unplugs-itself-after-it-completes-a-charge-108847 http://www.unplggd.com/unplggd/green-ideas/leech-plug-unplug...

davidw 17y ago

Huh... that's annoying. 95% of the time, I use the laptop in my home office and don't really want to mess around with plugging/unplugging it:-/

marcusbooster 17y ago
What about running it through a 6 outlet switch that you can readily turn on/off?
- davidw 17y ago
  The problem is that I shouldn't have to do anything. The computer should be able to figure this stuff on its own - after all, that's the kind of task that they're good for.
  - FlorinAndrei 17y ago
    Oh, the "computer" (read: the manufacturer) has it all figured out already, rest assured. They just don't want to give up on a few performance percentage points.
    - psadauskas 17y ago
      Or, more likely, selling you replacement batteries.
      - davidw 17y ago
        Ok, but at the same time, they could also tack some money on to the price for "batter life extending technology" and make money that way...
yungchin 17y ago
For desk use, it's best for your battery to remove it from the laptop once it's fully charged. You don't want to continuously plug/unplug your laptop because that would just cycle the battery a lot, and that's not good for it either. As for me, I usually just leave the battery in: it's a nice UPS, worth the expense of perhaps a few months of lost life.

niyazpk 17y ago

Where I stay in Bangalore, we have about 3 one hour power cuts per day. So my laptop battery is getting good exercise!

nazgulnarsil 17y ago

simpler solution than constant plugging and replugging for me was to remove the battery if I'm not going to be moving the laptop for an extended period.

chops 17y ago
It's nice having that battery as a UPS though, in the event of an outage.

mustpax 17y ago

So, why don't laptops completely bypass the battery when the battery is charged and the power is plugged in? If the laptop can work when the batteries are removed, it should be able to cut-off power to/from the battery when fully charged as well.

rdtsc 17y ago
When the laptop is at home, just charge the battery to 50% then remove it so it works only from the plug. I don't move my laptop as much as I did before and I noticed that I get much better battery lives than my friends who continuously keep their laptop plugged in and with the battery attached.
- mustpax 17y ago
  Obviously this is the current solution. I was pointing out that laptop manufacturers could remove the need for fiddling with your power connection by automatically disconnecting the computer from the battery when it is not needed.
  - eru 17y ago
    Yes, but you need a way to tell it whether you don't want to use the battery in a long time (so 50% charge is good), or whether you want to get up and go on the road soon --- where 100% charging is nice.
    - rdtsc 17y ago
      Allegedly Thinkpads have that. But I run Ubuntu on mine so I don't have access to the fancy bios setting utilities from Lenovo. I just snap the battery out. That seems to work for me.

BigZaphod 17y ago

I've had Apple laptops going back to the release of the Titanium PowerBook and I've almost always used them plugged in for the vast majority of the time and I've never had this dreaded battery death that articles like this talk about. However, I have a friend who seems especially apt at killing the very same batteries in the very same laptop models. My rather uninformed theory is that there's a specific kind of behavior that adversely affects them - but whatever it is, I don't do it and he does. I think the key is that he uses his without power a lot, running it down frequently, etc. which seems to be what this article is suggesting (and most articles about prolonging battery life suggest). Given my own experience, I'm continuously confused at the pervasiveness of this advice given how counter it is to my own experience - but perhaps there's some intelligence in the batteries/charger that's protecting me from myself? I mostly think of my battery as a built in UPS and not as a gas tank.

FlorinAndrei 17y ago
Right. So, don't run it down a lot, and don't charge it to 100% unless you have to.
nasalter 17y ago
FYI, Apple have a page providing advice on battery care: http://www.apple.com/batteries/ http://www.apple.com/batteries/ One of the things it says is... "Standard Maintenance 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 MacBook Pro 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."
- jrockway 17y ago
  For proper maintenance of a lithium-based battery, it’s important to keep the electrons in it moving occasionally." I knew I shouldn't have set my air conditioner to absolute zero...

Zak 17y ago

The article mentions that Thinkpads come with a utility to set the charging cutoff point. Has anybody figured out how to do this on Linux?

yungchin 17y ago
http://www.thinkwiki.org/wiki/Tp_smapi#Battery_charge_control_features http://www.thinkwiki.org/wiki/Tp_smapi#Battery_charge_contro...
sandGorgon 17y ago
bug filed - https://bugs.launchpad.net/ubuntu/+source/gnome-power-manager/+bug/428543 https://bugs.launchpad.net/ubuntu/+source/gnome-power-manage...

yungchin 17y ago

The article is right, but it's hard to read. If you don't read carefully, it seems to suggest cycling your battery more, when actually it just suggests not pushing it near 100% charge too long. Here's a complete and simple summary of good practice: http://batteryuniversity.com/partone-21.htm http://batteryuniversity.com/partone-21.htm (more details on other parts of that website) - for most geek-apparel, the LiIon column will be applicable.

jockc 17y ago

Seems like it would be easy for laptop makers to design something into the laptop to manage how the battery charges/discharges when it's plugged in. That way you could leave it plugged in 99% of the time (as probably many of us do) and not impact the battery negatively.

ANH 17y ago

Over the past four weeks my Macbook Pro battery's performance declined precipitously, and I think this is the cause. I tended to leave it plugged in whenever I was at my desk, which is most of the time. Got to the point where the MBP wouldn't last more than 5 minutes unplugged. Just received a new battery and all is well. Think I'll be giving this technique a shot.

sounddust 17y ago

Newer Sony laptops come with "Battery Care" software that automatically keeps the battery between 50 and 80% at all times. According to Sony engineers, a battery that is always kept at or below 50% will essentially never degrade in capacity.

there 17y ago
so what's the point of having a big battery then if it never charges to 100%?
- sounddust 17y ago
  Well, it's still more battery life than a small battery that never charges to 100%, right? I think regardless of the battery size, you can make the decision to preserve the long-term life of your battery or have the extra capacity in the short-term. Plus, charging from 20 to 80% is much faster than charging from 20 to 100% (I estimate that about half of the time is spent just going from 80 to 100).

bonsaitree 17y ago

While correct, I really view this as a non-issue. I suspect for most people, their in-memory data, time, and attention are far more valuable than not having power redundancy protection against an accidental cord disconnect or possible increased degradation on a ~$100 replaceable component on a $1k+ machine--namely the battery.

GeneralMaximus 17y ago

I've had my MacBook for 1.5 years now, and my battery life is still a little more than 4 hours. I keep my machine plugged in all the time, and completely run it down once a month. On the other hand, my friends who have the same MacBook have terrible battery lives. They use the laptop on batteries all the time. I'm inclined to believe this guy has no idea what he's talking about.