Design capacity & Full Charge capacity

[aki]

My battery is only 46mha when it's 100% full charge. but the design capacity says: 76. which one should i look? as this momemt, i can see the battery condidtion is on Yellow, 10counts only, which means it has drop 50% of the really full charge battery right? it supposes the reach the design capacity ?

[LtTPfan]

You are correct. It appears your machine, like my T30, has likely lived most its life connected to the AC adapter and rarely run off the battery. Your battery guage needs to be "calibrated." This is normal for machines with LiIon batteries and battery guages, and something IBM recommends you do monthly. You do this by deep-cycling your battery 1-3 times. To do this you need to disable the power management and alarm timers so your machine won't suspend or hibernate and allow it to run completely down till it shuts off, then recharge fully by charging it overnight while turned off. Left-click on your Battery Maximiser Guage then go to Battery Information>> Battery Health>> Battery Tips, then click on Reconditioning the Battery to be walked thru the process.

Mine started at 29.2 Wh full-charge with a design capacity of 47.5 Wh, and was also "yellow." After reconditioning as above (3 cycles) mine came up to 45.4 Wh, and is now "green." When I discharged my battery it went down fairly rapidly to 6%, about an hour and 15 minutes, then stayed at 6% for an hour before it started dropping to 0%. It still took several minutes at 0% before the machine shut off.

For others reading this, don't do this assuming it will bring your battery back to life, in fact it can further degrade your battery. This process is meant for machines that spend most of their time connected to the AC adapter and rarely run on the battery. Also, check your charge cycle count before doing this trying to rejuvenate your battery. If you've got a couple of hundred cycles, your battery is just worn; this will just cause more wear.

[aki]

I did the deep-discharge 2times. the day i brought this laptop home, it was RED, but after i deep-discharge the battery, it became yellow. and about the 0%, it took me more than 30min before the laptop went off, but in the monitor, you can see it says: 0% ( 1min)...so this must be some kinda weird.

[simms]

I have a battery that has been cycled 27 times, first used date around 2003-11. It holds around 38Wh when it is rated for 47Wh.

Would it be advisable to deep discharge it 3 times? I've used it to about 5-10% the past two days.

[LtTPfan]

...so this must be some kinda weird.

Not really, it just shows it needs recalibrating.

I have a battery that has been cycled 27 times, first used date around 2003-11. It holds around 38Wh when it is rated for 47Wh.

Would it be advisable to deep discharge it 3 times? I've used it to about 5-10% the past two days.

It sounds to me like your machine spends most of its time connected to the AC adapter and that you might benefit from performing the recommended monthly recalibrating. It may not take 3 deep-cycles. The tip mentions 1-3.

[amitra]

lithium ion batteries deteriorate at a rate proportional to the ambient temperature and charged capacity. For e.g. a batter at 90F and 100% capacity will deteriorate at 20% per year. A battery at 75F and 50% capacity will lose capacity at the rate of 5-7% an year. It's in your best interest to charge the battery to 100% only when required. Rest of the time use power manager to keep it at 40%.

[bill bolton]

It's in your best interest to charge the battery to 100% only when required.

Batteries are consumables..... they are going to wear out sooner or later no matter what you do and compared to the price of the laptop, the battery is inexpensive. Getting fixated on battery life to the point of regularly changing charging thresholds is just plain silly.

For most T4x users a battery is going to last at least a year before capacity is significantly impacted, and they can easily go for a couple of years for very many users.

It is in a user's "best interest" to get on with using the laptop, including having it ready to run for as long as possible off main power without specific notice.

Cheers,

Bill