Unplug Your Laptop to Keep Your Li-Ion Battery Healthy

Awww man! My Laptop has been plugged in for a few years... It's been discharged maybe 3-4 times within that period... I never take it off the charger to see if the battery is shot... I'll test it out tonight, and time the run time on the battery.

After killing the original laptop battery by leaving it always plugged in I had to buy a new replacement. I use the new battery only for the road and it has lasted for years.

I keep the old laptop battery in when working at the office. The old battery has a few minutes of life – but just enough to make it through an intermittent power loss without losing whatever file I was working on.

I've worked with enough Mac laptops (my own and many others), to definitely agree with Apple: it is definitely better to use the battery occasionally. Fortunately for me, I fly a couple of times a month - Just right to keep my battery exercised by working while on the plane.

There are procedures for rejuvenating Li ion batteries. Draining it all the way down (ignoring the warning that you only have x minutes left), followed by fully recharging, then repeating the process a couple of times, helped mine significantly. On the other hand, after about three years, it is about time to get a new one!

Is there ANY hope of companies making Li ion rechargeable aaa,aa,b,c,d batteries?

I really don't think that this is true. I'm no expert but I have a doctoral student friend studying energy storage methods, part of which was involving battery technology. We had a discussion about this same topic.

People often say that discharging their battery all the way improved their battery life, the capacity most assuredly didn't actually improve, just the software that calculates the battery life re calibrated itself. Your watt hours is almost guaranteed to be the same or slightly less after a complete discharge.

Read entire column for lithium ion batteries:

http://www.batteryuniversity.com/partone-21.htm

I believe battery university to be true because it is exactly what my friend said as well (who learned this stuff from a phd level class and from published engineering textbooks).

I was told that the structure of the lithium ion batteries can be thought as such: The anode and cathode are made so that the mobile electrolyte can move between the two. The structures can be thought of little hollow cubes and when the electrolyte moves between them the material eventually fatigues, breaks and loose their capacity to hold the electrolyte. This is why you store your battery for long periods of time at "50%" because the electrolyte is half in the anode and half in the cathode. The number your computer gives is probably not actually 50% of the electrolyte distributed as such. Actually it might make sense to store your battery at a level higher than 50% because they can sometimes discharge at 5% of the remaining capacity per month. Then you could have the average capacity at 50% over that time period. Battery university says store at 40% but you probably don't even know what is accurate on your computer and it's probably where the difference between 40 and 60% is already past the point of diminishing returns so it's already much better than storing at 100% or 0%.

LiIon batteries loose capacity with heat, cycles and age. If apple makes a charger that overcharges their cells that's just lame. It has to be some non engineer at apple that posted that thinking of nicad batteries or something like that. You just don't discharge LiIon batteries all the way to cycle them. And laptop batteries just rarely last longer than 3 years anyways. My Thinkpad battery is almost 3 years old and is down to about 80% of it's new capacity, but that is because I rarely cycle it and leave it plugged most of the time. I must have only about 50 charge cycles on it. Plus I have the software set so that it doesn't charge to 100% but only to about 96% and doesn't start charging until it's below 92%. Every little bit helps make a battery last longer.

What does everyone else think?

In my experience, battery technology has come a long way and finally the other brand x boxes have arrived at the performance level of Apple in battery/power management.

But I know there was a 4-6 year period way back when that I could look around in an airport and see the apple guys sitting where they wanted to, and the non-apple guys huddled around the power outlet. Again, I believe that this may be partly attributable to power management, which apple is still superior at, IMO.

I just replaced my ibook battery after 4.5 yrs use. I have a dell battery that is about 3 yrs old now that is probably in as bad of shape but this one is plugged in most of the time (wife's computer) so I'm not too worried about replacing it.

My ibook does get hot while charging, which may partly drive the recommendation of not leaving on the charger all the time. Once charged, the unit cools significantly.

I had a mac powerbook back in the late 90s that gave 4 hrs of use on a charge and those batteries conked out after about 4 years. Those were the first LI-ion batteries that I owned. And those batteries were twice the volume of the battery in my ibook!

Right wrong or otherwise, there has to be a grain of truth somewhere in the apple recommendation, as I am one to not tinker too much with success.

I'm only one vote away for a good answer

I think I was the only one to explain the physical reason for why lithium ion batteries are damaged by long term storage with full or depleted charge. I think I might deserve my first "good answer"

In my personal experience, continously plugged into the mains damages batteries, though I personally find this amazing that companies cannot provide a charger that does not damage the battery.

But I have seen this on many makes of Laptop.....

I always run at home with the battery removed completely. The battery gets recharged and used about once every 2 months or so, it is not showing any signs of problems up to now.

My softwares are set up to make automatic regular backups. I have not lost anything up to now, in spite of losing power a few times.....once my wife pulled out the wrong plug!!

Laptop batteries only need to be used when mobile.

If your mains is so bad that its needed, then remove the mains plug when the battery full, and replace it when down to 10% etc etc etc.....

Too many people buy Laptops who do not need them, a PC is more powerful for the same price and all the parts can be easily replaced. A Laptop may even need to have special tools to dismantle it......

GA

Your comments fit in EXACTLY with my experiences over the last 12 years or so and 60 odd laptops bought every 2nd or 3rd year in the company I worked for.....I still have several of them!!!!

We have a in use still:-

a Toshiba 486 which runs an old 286 version of Eagle for schematics and PCBs at high speed with Windows 3.1. Battery is defunct now. But I still have a never used new battery for it....

Toshiba Pentium 120 for controlling my CNC machine with Win98SE. Battery still fine.

2 x Siemens Laptops 3 years old, I forget the model as my Daughters use them for email. Both batteries are still perfect, they take them out!

and a Centrino Duo Toshiba Tecra A8 on which I am typing this.....over 2 years old and the battery is fine. But on the shelf!

I have two computers, an Apple MacBook Pro and HP dv7. When not traveling the HP's battery is removed at ~50% capacity and put away until needed or I cycle it, about once a month and it has continued to work perfectly. I started to do the same with the MacBook and found this computer does not like running without the battery installed. Slow start-up and Very slow shutdown. Re-installed the battery and everything returned to normal.

I don't know the reason for the differences but noticed with the new MacBook Pro's the battery is not user accessible.

I will continue this process with the HP however.

Well, I tested my battery last night. My HP laptop (the video machine) has been plugged in and used as if it were a desktop for the last 2-4 years. I don't know If the battery has been fully discharged once in that period. Last night I unplugged it from life support and made it run on battery power... I got about 1:45 minutes worth of use, which is fairly close to what it did new.. While it was running on battery, It was doing it's normal work (watching TV over the Wi-Fi). New I could watch one movie on one charge. so... Meh.

Cool. It kinda supports my theory, because all LiIon batteries loose capacity over time regardless of use.

Then it would appear that HP put a quality charge controller in that laptop.

There is no need to ruin a battery with a cheap charger, but most do!!!

The charge controller gets quite warm when it's plugged into the wall. I've had to strip and re-solder the actual plug that goes into the laptop a couple times. Other than that (and the missing "D" key), that cheap laptop I bought for 300 bucks 4 years ago has worked awesome for it's prescribed use as a strictly internet/TV/Movie machine.

My strictly Music recording/mixing/mastering desktop machine however, is an entirely different story.

That thing that plugs into the wall is the power supply, also called power adapter. The charge controller is in the PC. The charge controller must monitor more than just the battery voltage, so it really can't be included in the power supply, unless there are 5 or more pins on the connector between the power supply and the computer.

FULLY CORRECT!!

One small point, even the ones with 5 pins are not always the ones with the charge controller in the power supply, sometimes the supply makes more than one voltage for various parts of the PC - +12, -12, +5, -5 for example also needs 5 pins......(at least!)

Ah yes. Sorry.