Thinkpads Forum

Is it safe to keep the battery in my x60s when it is shutdown but i still have the charger plugged in and the mains still on? will it decrease battery life?

It's safe. However, most battery resource sites recommend removing your battery and keep it stored in a cool dry place with about 60-80% charge. That is what I do and I have over 3.5 years on original T42 battery which still holds a good charge.

And is it safe to use the Thinkpad while plugged into AC power with the battery removed? I'm wondering if the notebook was designed to be used with the battery installed all the time ...

most of the times, i always keep my thinkpad docked in and connected to my ext. display..and i always remove the battery and do that because i sit on the comp for loong hours before i go back to college..and doing so, not only has given me good battery life [ in terms of backup and battery life ] but also as mentioned 'treker' battery life increases very much..reason being that since every battery has certain amount of charge cycles, the more we charge and discharge the battery, the more the life of the battery drains away..so if u limit urself in charging ur laptop too often then life of battery vil increase..

sportfreak wrote: but also as mentioned 'treker' battery life increases very much..reason being that since every battery has certain amount of charge cycles, the more we charge and discharge the battery, the more the life of the battery drains away..so if u limit urself in charging ur laptop too often then life of battery vil increase..

Thank you for your reply. It's my understanding that lithion ion batteries also have a shelf life. I wonder if it's all a wash. I suppose for maximum battery life, there must be a balance. I ordered mine with a nine cell battery, and then I ordered a spare nine cell battery, so that I can stay unplugged longer (should I want to spend the day on the cafe's outdoor patio ). The original battery has 95 cycles, and my spare battery has five. The original is the one I leave connected to AC power longer. I suppose that, eventually, I will find out which method is conducive to longer battery life.

Tony

It's my understanding that lithion ion batteries also have a shelf life. I wonder if it's all a wash.

Most agree you can maintain maximum charge so long as batteries are stored between 40 and 60% of maximum. Its unlikely even "New Old Stock" batteries are stored in this way, of course, but its still wise to rotate your personal battery stash if you're the unplugged type.

x60s and x61s (and presumably all modern Lenovo laptops) are smart enough to not charge when within 5% of maximum charge, effectively saving wasted cycles. Many of us use software control to limit charging to more conservative numbers, though, again maximizing the life of batteries by limiting the number of full charge cycles.

To reply the original question, I'd say that it is OK, if you leave it there for like a few hours (like, when you need to go out for the day or something).

But, not too to leave it like that for more than 3-4 days, IMHO.

Personally, for storing batteries, I only store it at 40%, and it's working great for me. My batteries are coming close to 2 years of age and I still have around 63~65% of the original designed capacity.

Comage wrote:<snip>
Personally, for storing batteries, I only store it at 40%, and it's working great for me. My batteries are coming close to 2 years of age and I still have around 63~65% of the original designed capacity.

I get just about that much after 2 years by doing nothing at all (just leave the battery in the machine and use it). The use-up curve is not linear, and after the 3rd year, batteries are pretty much toast. ... JDH

Do you ever get reminders to reset your battery gauge?

Comage wrote:Do you ever get reminders to reset your battery gauge?

I'm wondering the same thing. I have mine set to give reminders, but I haven't seen one yet.

tyanlion wrote:Is it safe to keep the battery in my x60s when it is shutdown but i still have the charger plugged in and the mains still on? will it decrease battery life?

Safe? Yes. Negatively affects battery life? Possibly.

Lithium batteries degrade due to several mechanisms.

Lithium cells degrade with use. I believe the degradation is dependant on energy removed / added and not specifically to the number of charge cycles. In other words, it is probably the same to charge/discharge the battery 10% 10 times as it would be to fully charge / discharge it once.

Lithium cells degrade with age. Lithium cells begin to degrade the moment they are manufactured and this continues until you take them out of service and recycle them. The amount of degradation depends on the state of charge and the temperature. The higher the temperature and the higer the state of charge (ie., cell voltage), the faster the cells degrade. I am not sure how linear this effect is.... I have been trying to get better info for some time since I use lithium cells in model aircraft and there is some anecdotal evidence that storage at full charge is worse than storage at (for example) 90% charge.

Lithium cells will be permanently damaged if discharged below something between 2.5 and 3V per cell. In a laptop battery, the cells will very slowly self discharge due to a combination of internal leakage and the current drawn by the protection circuitry in the battery pack. The oft quoted 50% charge figure for storage is merely what the cell manufacturers use for initial charge and shipment, and is a compromise between full charge (bad for long term storage) and zero charge (ie., 3V/cell, and as good as it gets, but no protection from subsequent damage due to self discharge).

So to distill all this..... I don't worry about it and leave my battery in the laptop 24/7 with the mains on. Yes, the battery would last a little longer if I took it out between uses, but only if it was substantially lower than full charge when I removed it. And each time I discharged it to "substantially lower than full charge " prior to removal would count as a partial cycle. Not sure if the savings due to removal and storage at partial charge would be offset by the degradation due to the frequent partial discharges.

Note that some battery managers (like the X41 and probably the X6x) allow you to specify the level of charge where the charger kicks in. This is a partial compromise.... set it for (say) 50% and the charger will stay off until the battery falls below 50%.

Probably more than you wanted to know

Paul

I would just use the laptop as designed and most convinient to your uses. Life is too short to worry about a $100 laptop battery replacement every 3 years.