How can I prolong my 8 cell battery?

I own a x61, I'd like to prolong my battery life as much as possible. I am currently using Lenovo's power management software. Is it better to set my own constraints, say... charge till 95% only, or is the "Optimize for battery lifespan (automatically charge for me)" the better option?

 

Below is an extract from Wikipedia, which I originally posted in Sony forum for the benefit of VAIO users :

Guidelines for prolonging Li-ion battery life
Unlike Ni-Cd batteries, lithium-ion batteries should be charged early and often. However, if they are not used for a long time, they should be brought to a charge level of around 40% - 60%. Lithium-ion batteries should not be frequently fully discharged and recharged ("deep-cycled") like Ni-Cd batteries, but this is necessary after about every 30th recharge to recalibrate any external electronic "fuel gauge" (e.g. State Of Charge meter).
This prevents the fuel gauge from showing an incorrect battery charge.

Li-ion batteries should be kept cool. Ideally they are stored in a refrigerator. Aging will take its toll much faster at high temperatures. The high temperatures found in cars cause lithium-ion batteries to degrade rapidly.
According to one book, lithium-ion batteries should not be frozen (most lithium-ion battery electrolytes freeze at approximately −40 °C; this is much colder than the lowest temperature reached by household freezers, however).

Li-ion batteries should be bought only when needed, because the aging process begins as soon as the battery is manufactured. When using a notebook computer running from fixed line power over extended periods, the battery should be removed, and stored in a cool place so that it is not affected by the heat produced by the computer.

Storage temperature and charge
Storing a Li-ion battery at the correct temperature and charge makes all the difference in maintaining its storage capacity. The following table shows the amount of permanent capacity loss that will occur after storage at a given charge level and temperature.

Permanent Capacity Loss versus Storage Conditions :
Storage Temperature....... 40% Charge.................. 100% Charge
0 °C (32 °F)...................2% loss after 1 year.......6% loss after 1 year
25 °C (77 °F).................4% loss after 1 year.......20% loss after 1 year
40 °C (104 °F)...............15% loss after 1 year......35% loss after 1 year
60 °C (140 °F)...............25% loss after 1 year......40% loss after 3 months
Source: BatteryUniversity.com

It is significantly beneficial to avoid storing a lithium-ion battery at full charge. A Li-ion battery stored at 40% charge will last many times longer than one stored at 100% charge, particularly at higher temperatures.

If a Li-ion battery is stored with too low a charge, there is a risk of allowing the charge to drop below the battery's low-voltage threshold, resulting in an unrecoverable dead battery. Once the charge has dropped to this level, recharging it can be dangerous. Some batteries therefore feature an internal safety circuit which will prevent charging in this state, and the battery will be for all practical purposes dead.

In circumstances where a second Li-ion battery is available for a given device, it is recommended that the unused battery be discharged to 40% and placed in the refrigerator to prolong its shelf life. While the battery can be used or charged immediately, some Li-ion batteries will provide more energy when brought to room temperature.


rgds.

 

I haven't seen any difference between Optimize and Fully Charged. Making your own custom charge thresholds, IMO, is the best way to prolong battery life. I have mine set to 36/40.

Please read the Battery Guide for more information.

 

If you set your charge to never go over 40% doesn't that kinda defeat the purpose of having a big battery. Isn't it like using 4cell with a charge of ~90%. It would be lighter and cheaper, would it not?

 

It doesn't defeat the purpose when you're not going to be mobile. I only use that threshold setting when there's an outlet nearby.

 

why do people worry about this..your battery will last at least 1 year no matter what...if it starts to hold less charge than you want just get another..its really no big deal

 

Personally, I've never had a battery that didn't outlast the 1-year mark, Eskimo. And I value both my money, and not being part of a disposable economy, especially when that disposal has some environmental impact.

To the OP, I went to the ThinkPad Power Manager software, and under Battery Maintenance, I set the charge threshold to "Optimize for battery lifespan (automatically change for me)". I'm sure I'll have to wait to see the results, but it's a simple automatic way of doing things without monkeying with my own manual charge threshold settings.

 

I've personally never had the optimize setting do anything for me; it was pretty much like the full charge setting.

If it ends up being different, I'd like to know how.

 

I agree with you; I can't be sure that it does what it claims to do. I just found that it didn't do anything detrimental, so I left it on. Only time will tell; my battery is too new to know.