Thinkpads Forum

Hi there,

Anyone think it is neccessary to remove the battery (to prolong the battery lifetime) is neccessary?

Does (mostly) anyone actually leave it or just remove it?

With a modern laptop (newer than 5 years), it is not necessary to remove the battery when on AC. Further, for the very rare time when I lose AC power, the battery saves the situation. ... JDH

my point is that if you leave the battery in, and if you use the charger (the battery is under heated up environment) dont it sort of deplete its lifespan faster? I am not talking about the no. of full discharge cycle.

ylim wrote:Anyone think it is neccessary to remove the battery (to prolong the battery lifetime) is neccessary?

Not all the times. However you should remove it once it's fully charged. Overcharging is bad and can kill Lithium ion cells.

ryengineer wrote:Not all the times. However you should remove it once it's fully charged. Overcharging is bad and can kill Lithium ion cells.

Do pardon me for not making myself clear. It is clearly true that I am refering to leave the batt in extended period.

Btw, do you think laptop manufacturer / lenovo is smart enough to prevent overcharging? I am an electrical engineer and there are abundant charging chips available which should be smart to prevent overcharging (and they are cheap and should be in).

So is there a real need to remove the batt (when it's fully charged).

ylim wrote:my point is that if you leave the battery in, and if you use the charger (the battery is under heated up environment) dont it sort of deplete its lifespan faster? I am not talking about the no. of full discharge cycle.

Nope. My T41 is four years old, has the original battery, and is plugged in most of the time. The battery is a piece of chemistry and expires on its own, so my battery is now only good for about an hour and desparately needs replacing. But that has nothing do (in any great way) with leaving it plugged in. It most assuredly does not run hot. ... JDH

You can set charging thresholds so that the laptop will only charge when it falls below a certain level and will stop when it reaches a certain level. By setting the top threshold below 100% you can allay your fears and not need to remove the battery.

jdhurst wrote:Nope. My T41 is four years old, has the original battery, and is plugged in most of the time. The battery is a piece of chemistry and expires on its own, so my battery is now only good for about an hour and desparately needs replacing. But that has nothing do (in any great way) with leaving it plugged in. It most assuredly does not run hot. ... JDH

The 'natural chemical decay' of a Li-Ion battery decreases significantly at lower temperatures. This is why it's a good idea to store rarely-used batteries in the fridge. There are some useful figures and description of the phenomenon here;

http://www.batteryuniversity.com/partone-19.htm

According to that, if you stored your 100%-and-never-used battery in the fridge for a year (0-4 degrees C), rather then keep it in the machine (25 degrees C), its charge capacity will only decay 6% rather than 20%. Better figures yet, if you stored it at 40% capacity rather than 100%.

rek wrote:<snip>
According to that, if you stored your 100%-and-never-used battery in the fridge for a year (0-4 degrees C), rather then keep it in the machine (25 degrees C), its charge capacity will only decay 6% rather than 20%.

I know that to be true; however, my T41 is a working machine, moves around, plays on battery some of the time, and so on. So keeping the battery in the fridge is not really an option for me. Still, I do understand your point. ... JDH

jdhurst wrote:I know that to be true; however, my T41 is a working machine, moves around, plays on battery some of the time, and so on. So keeping the battery in the fridge is not really an option for me. Still, I do understand your point. ... JDH

As I understand yours I have a slim battery that I leave in the system, for when it's chained to a desk 90% of the time and is used away from the office now and then for short periods where ultimate portability is important, and total battery life isn't. I more or less expect this battery to die early of a hard life.

I also have a high capacity battery that only gets used when I know I'll need all-day runtime; given that maximum charge capacity is important, this one stays in the fridge until I need it. (I store it at 100% charge for convenience sake though, I don't want to have to spend X hours waiting for it to charge up before heading out for a day)

I keep the battery in my laptop non-stop. Will this decrease lifespan of the battery? Perhaps a little bit but I just do not care. Battery serves me and not the other way around. Battery in fridge is as good as beer in the sun and I do not want to make a fetish of the battery. I use the battery mostly to move laptop from one place to another and I need to feel secure while I work especially in huricane season here in FL
I need one battery every 2-3 years and that is more than acceptable.

Should leave it on...
Batteries will inevitably die out after several years

Leaving it on can have it acts as a surge protectors and UPS... Do you want to risk having the laptop shut down suddenly and all your data and work that you are working on gone with the power?

You have your lappy downloading something that takes hours if not days and then there is a failure with the electricity, the installed battery can save your work.

Li-ion batteries are best stored at a little less than half charge (40%).

If you are leaving it in your laptop at full charge for prolonged periods of time (think weeks or months), then the battery will significantly lose it's charge. Or you may experience a sudden drop when you are on batteries, say, when the battery drops to 50%, it doesn't go to 49% but goes to 40%. The numbers in between seems to have gone missing. That is a sign of a spoilt li-ion battery.

If you have to have it in your laptop, make sure to cycle the battery at least once a week, and perform a deep discharge (drain to 1%) on a monthly basis.

Otherwise, just be prepared to fork out money for another battery when your so-called UPS fails.

Comage wrote:Li-ion batteries are best stored at a little less than half charge (40%).

The keyword is BEST. The thing is perhaps to note that there should not VERY drastic drop in charge retention if you dont store at half charge. I guess the more significant contributor is the storage temperature. We often talk about ideal / best but dont actually look at how bad we suffer if we don't follow the norm.

Comage wrote: If you have to have it in your laptop, make sure to cycle the battery at least once a week, and perform a deep discharge (drain to 1%) on a monthly basis.

I think the fact that we can ask thinkpad 's batt manager to tell us to perform a deep cycle discharge automatically. It should be ok?

milstein wrote: Leaving it on can have it acts as a surge protectors and UPS... Do you want to risk having the laptop shut down suddenly and all your data and work that you are working on gone with the power?

For UPS you might be correct, but a surge protector, I doubt.

smvp6459 wrote:You can set charging thresholds so that the laptop will only charge when it falls below a certain level and will stop when it reaches a certain level. By setting the top threshold below 100% you can allay your fears and not need to remove the battery.

I have set it to automatic thinkpad management for best batt lifespan.

Thinkpad Power Manager does its job well,

Not that I have any issues against the Thinkpad Power Manager, but when your battery has charged up from a low level, and reaches 98%, and PM tells you all it needs is 5 more minutes to finish charging, but you look at PM again 15 minutes later and it still says 5 more minutes, just doesn't seem right to me.

Comage wrote:Not that I have any issues against the Thinkpad Power Manager, but when your battery has charged up from a low level, and reaches 98%, and PM tells you all it needs is 5 more minutes to finish charging, but you look at PM again 15 minutes later and it still says 5 more minutes, just doesn't seem right to me.

interesting

Comage wrote:Not that I have any issues against the Thinkpad Power Manager, but when your battery has charged up from a low level, and reaches 98%, and PM tells you all it needs is 5 more minutes to finish charging, but you look at PM again 15 minutes later and it still says 5 more minutes, just doesn't seem right to me.

I note that your obversation too. I believe this is due to a psedo-real time deterministic approach of realising the time of charge level. Perhaps at time a, you doing less computing and at time by you suddenly do more computing. A good example is to observe the battery level (thinkpad) when you boot your x60. Note that when it stablises, the charge left time surges up.

I prefer to leave the battery in at all times, in case there is a power failure.

ylim wrote:I note that your obversation too. I believe this is due to a psedo-real time deterministic approach of realising the time of charge level. Perhaps at time a, you doing less computing and at time by you suddenly do more computing. A good example is to observe the battery level (thinkpad) when you boot your x60. Note that when it stablises, the charge left time surges up.

I have to admit that the laptop was idle when I was looking at the PM timer, with a watch in hand.

If you're into R/C cars, you know you always drain the batteries before you charge with those tiny light bulbs.

So I wait 'til mine goes to zero then I standby, if i'm not plugged in.

I also set it to start charging only when it's 2% (that's the lowest you can go) So even if the battery is left on with the laptop plugged in, it won't charge and you have backup.

anytime you charge before it's empty, you shorten its lifespan. I don't care what they say --all batteries hold memory. I have 5 laptops.

My X60s battery Full charge capacity still matches its design capacity at 78.14

I'll give updates on this.

berlin wrote:If you're into R/C cars, you know you always drain the batteries before you charge with those tiny light bulbs.

So I wait 'til mine goes to zero then I standby, if i'm not plugged in.

I also set it to start charging only when it's 2% (that's the lowest you can go) So even if the battery is left on with the laptop plugged in, it won't charge and you have backup.

anytime you charge before it's empty, you shorten its lifespan. I don't care what they say --all batteries hold memory. I have 5 laptops.

My X60s battery Full charge capacity still matches its design capacity at 78.14

I'll give updates on this.

Deep cycle discharge isnt healthy for a Li-ion. And most RC batts are NiMH. Stubbornity dont give you an increased batt lifespan.

lol here's a good discussion

http://episteme.arstechnica.com/eve/for ... 6003014731

10 - 15% is probably the best time to start charging, but don't charge it 100%?