should i empty the battery to 0%?

I'm not sure what will happen if i use and empty the battery of my thinkpad to 0%, so should i do this? is it harm to machine?

(I always plugs in the AC adapter when the battery remain 10%)

 

No you should not. It can decrease the battery's life. Search for proper battery care. There have been a number of discussions on setting thresholds and proper storage, etc.

 

It won't harm the battery. All properly designed Li-ion batteries have protection circuits built into them (or the device using them) so that they don't over discharge to the point of damaging the battery. It'll shut off before that happens.

 

This is a half truth. Li-Ion batteries do have a cutoff circuit that stops them from being discharged before they are thoroughly damaged. However, "deep-cycling" the battery on a regular basis WILL reduce its charge capacity and service life at an accelerated rate.

 

Yes, damage and decrease of life are sort of separate

 

I'm not sure if you CAN discharge a Li-Ion battery to 0% in a laptop. I remember doing a lot of things to Ni-Cad batteries on the bench to try to revive them--which in retrospect was (mostly) a waste of time. Batteries used to be so expensive that taking them to a faith-healer--if you could get 6 more months of use--wouldn't have been a stretch.

Now? Li-Ion produce relatively stable voltage on discharge--it is the ampherage (current) which drops. Their behavior is different than that of other battery technologies. If they don't perform fairly close to spec, you recycle them. To do otherwise is to invite possible disaster.

Once in a great while--when the run time of the battery and the estimated runtime in the software don't match--you run a T60 (and some other models) until they automatically shutdown and then do a full charge to recalibrate the battery and power management software. Li-Ion batteries are a vast improvement over the old ones, but there is still a degradation in performance over time which must be accomodated. It is only necessary to do that a few times over the life of the battery.

I also do a full charge-to-shutdown (then charge) cycle when replacing a battery to reset the software (especially if it is a used-but-good battery.) It is something which I should look up myself to see if it is still necessary with the newer versions of the power managment software.

Of course as a tech, I have to be sure that the battery performs as expected so I don't have twice the time invested in a single repair--and have the best odds of a happy customer. (The odds are never 100%--in one memorable case, the keys started coming off the keyboard in the shop after I replaced the hard drive. I hadn't even touched the keyboard--I ghosted a factory image onto the replacement hard drive using a different computer!)

PS: The battery should have stable performance for quite a few charge/discharge cycles (in the multiple 100s,) if you have a sudden change in run-time--with the same performance settings in the laptop--you need to have the laptop and battery checked by someone who really knows what they are doing. While it can be a sad and untimely demise of the battery; it also can be other more ghastly things. You have a warranty for a reason--use it.

 

When calibrating the battery, the built-in option of Power Manger discharges the battery to 0% and only then starts the charging.
Although, I don't consider it reasonable to discharge it to 0% every time except calibrating.

 

I would recommend not discharging the battery to 0% unless recalibrating. From my observation with my T43 for 3.5 years, the battery life takes a substantial hit if it discharges below 5% or charges over 95%.

 

oh! I always using with AC adapter is pluged in, and my battery is always at 100%!!! Do this recommend?

 

I use charge thresholds to prevent my battery from going over 95% on most occasions. I use a start at 60%, stop at 95%. This also has the side benefit of charging far faster (the last 5% are a very slow "trickle" charge).

 

As you said that, your battery never remain 100%? really?

In summary, for the best way of increasing battery lifespan that we try to prevent the battery "in charging" (if we always using AC adapter), is it true?

 

Yeah. Always charging or always charging to 100% will definitely shorten the battery lifespan.

As everyone's pointed out, it's best to avoid 0% and 100%. Due to rolling blackouts where I live that last about 60 minutes, I keep my own battery thresholds set to just give me about 1 hour and 10 mins of battery life. It's set at something like always charge to 50%

 

For long term storage of Li-ions (I'm talking to you, Rockyspk), it's usually advised to charge it to 80% and keep it cool (not cold). So, in other words, having it fully charged and kept at that charge is really not a good idea. At least empty it once every two months.
You see, the thing about Li-ions is that although they (unlike NiCD and NiMH-batteries) don't suffer from any memory in theory, this changes the moment you have the circuitry to measure it's condition, making it necessary to recalibrate the "meter" once in a while.

 

thanks all Now i know how to charge my battery for the best battery lifespan!!

In summary:

1/ should not empty the lion battery to 0%
2/ limiting and preventing your battery in charging status
3/ should not keep the battery remain 100% for a long time using AC adapter
...etc
Supplementing please!
thanks a lot!