detach the battery or not?

I know battery life decrease over the time. To keep it in the best condition since the very beginning I have been reading some tips.
Lenovo says some things here:
http://www-307.ibm.com/pc/support/site.wss/document.do?lndocid=PFAN-3QNQJN
"The following instructions provides tips on how to obtain the best battery condition to extend battery rundown time:

* Once you have started charging the battery pack, do not use it until it is fully charged.
* If your battery is brand new and you are charging it for the first time, your battery may not be charged to full capacity due to characteristics of chemicals in the cell. To obtain maximum performance, all chemical materials in the battery must be fully activated. In order to achieve this:
- Cycle the battery (fully charge, then fully discharge) three times.
- Cycling the battery three times is also recommended if you have stored the battery for a few months.
- Do not charge the battery pack until all of its power is used. Partial charge or discharge causes a lack of uniformity of activated chemicals in the cell, and may cause performance degradation."

The last sentence makes me wonder, is it a good idea to detach the battery (having partial charge) while having the Thinkpad connected to the electricity outlet? I mean, as it says is not good idea to make partial charges, if I plug the AC adapter, the system will start to charge the battery from a partial charge! which seems to be a bad idea ... or not?

 

You may find lot's of different opinions on this matter here. Personally, i use the Thinkvantage Power Manager, i set it to charge when battery is below 80% and until 95% and that's it. Thus, battery is never "fed" with power. Of course, i never leave it to reach below 20%. Thus i expect to gain over time more battery life...I never take it off from my machine.

 

I'm with objectref on this one, and I have a similar custom power profile. Exhausting the battery is not good for it:
http://en.wikipedia.org/wiki/Lithium_ion#Guidelines_for_prolonging_Li-ion_battery_life

Removing the battery is an inconvenience, I would rather buy a new battery every few years than deal with unplugging it. With the proper power profile the effect is the same anyway.

 

That means that if your battery has 50% of charge, you start to charge it anyway? (not letting it to discharge until something like 5%)

 

Just read the Wikipadia article and it says:
"... When using a notebook computer running from fixed line power over extended periods, the battery should be removed ..."

Well I can see, this thread could be very controversial!

 

I have had my battery plugged in since day one which was last August. According to ThinkVantage Power Manager, the total capacity that it can hold only decreased by about 3-4%. Went through 95 cycles btw. Battery maintenance is overrated IMO. Just make sure you don't fully drain it or keep it at a high capacities for extended periods. For example, I keep my threshold at 40% when I'm plugged in.

 

Sure, if the battery is that important then remove it. To me the whole point of having a laptop is to be mobile and removing the battery takes away the mobility. It also takes away the built-in UPS functionality.

I think the statement quoted above is mostly intended for laptops without any proper power management. My wife's Dell for example will always charge to 100%, Lenovo is the only one I've seen that allows custom thresholds.

 

You've got part of it. The other part of it is that even when you've proper power management feature, the heat generated by your machine will still speed up battery degradation.

Wikipedia simply states the "technical ideal" practice.

In reality, users prefer the convenience and benefits that an attached battery can offer.


rgds.

 

I keep my battery in too. I can't risk losing my data due to a power failure of any sort. So according to Thinkvantage Power Manager, I'm losing a hundredth of my possible battery capacity everyday which honestly is not that bad.

However, since I am plugged in most of the time, I'm truly unsure as to how charged my battery should be when it is plugged in. I think all Thinkpad users should submit their charge thresholds so we can decide what levels are best. - Right now, I've left it up to the powermanager to "optimize battery lifespan" which seemed like a good call to me.

 

Wow I know a very very very very very very very very good website that explains all this:
Just read the info about lithium ion batteries but Ni-Cd, Ni-Mh, and lead acid is interesting too if you want to read it
http://www.batteryuniversity.com

 

I leave mine in and it's plugged in all the time. I just set the threshold to charge when below 80%

 

I use my laptop on AC 99% of the time. I leave the battery plugged in and have it set to start charging at 40% and stop charging at 50%. When I know I'm going to be traveling, I change the settings ahead of time to fully charge the battery before I leave.

I came to the conclusion that these were the ideal settings for my usage pattern a couple of years ago after having read up about the various battery chemistries and their characteristics at the Battery University site.