Laptop Storage (Battery Degradation?)

[l337]

Hi All,

With my work we store a large amount of laptops which may not be used for periods of time(1-3 months) recently my supervisor instructed me that it was not a good idea to leave the batteries in these laptops as it can degrade the battery life. Just wondering if anyone has ever heard of this? I do know that leaving a laptop charging can degrade battery life but if its not charging there shouldn't be an issue right?

 

[ClickRight]

I'm not entirely certain, however, I'm sure it would be the best if they were removed (in case the laptop were to turn on due to not being shutdown, wake on lan, etc). Reason being, if lithium ion batteries are completely discharged for any length of time it will wear out the cells, fast! It's best to store laptop batteries at about a 40% charge level.

If you can shut them down at that level, ensure they are not turning on for any reason, and store them in a cool, dry place, you'll probably be alright, but if it were me I'd take them out.

 

[vdub12]

It does not mater. Modern laptop batteries die with time not charge cycles. A brand new battery on the shelf in a box will die in the same amount of time as one in a notebook being used everyday. It's just the way lithium ion works.

 

[waynebob]

All you ever wanted to know about batteries and more at Battery University.
http://batteryuniversity.com/learn/article/how_to_prolong_lithium_based_batteries

 

[gazza]

Laptop batteries degrade because of heat. Users leave them in when they are fully charged and they continue to use the laptop with the ac power adapter connected. When a laptop runs on ac power the laptop runs hotter than when on battery power, so if the battery is fully charged then take it out if you are going to continue to use the laptop with ac power. It is the heat that degrades the cells in the batteries.

 

[tminer]

Laptop batteries degrade because of heat. Users leave them in when they are fully charged and they continue to use the laptop with the ac power adapter connected. When a laptop runs on ac power the laptop runs hotter than when on battery power, so if the battery is fully charged then take it out if you are going to continue to use the laptop with ac power. It is the heat that degrades the cells in the batteries.

I have to disagree with this practice. What you say may be true but for a laptop if users use the laptop without a battery and they bump the powercord the wrong way the laptop will shut off losing anything they were working on. It would be hard for me to advise customers to charge the battery then remove it.

 

[johnrobert]

The new batteries don’t suffer from storage
But to leave it on permanent charge will degrade it

 

[phaZed]

Cell life:

Charging forms deposits inside the electrolyte that inhibit ion transport. Over time, the cell's capacity diminishes. The increase in internal resistance reduces the cell's ability to deliver current. This problem is more pronounced in high-current applications. The decrease means that older batteries do not charge as much as new ones (charging time required decreases proportionally).
High charge levels and elevated temperatures (whether from charging or ambient air) hasten capacity loss.[45][46] Charging heat is caused by the carbon anode (typically replaced with lithium titanate which drastically reduces damage from charging, including expansion and other factors).[47]
A Standard (Cobalt) Li-ion cell that is full most of the time at 25 °C (77 °F) irreversibly loses approximately 20% capacity per year. Poor ventilation may increase temperatures, further shortening battery life. Loss rates vary by temperature: 6% loss at 0 °C (32 °F), 20% at 25 °C (77 °F), and 35% at 40 °C (104 °F). When stored at 40%–60% charge level, the capacity loss is reduced to 2%, 4%, and 15%, respectively.[48][citation needed] In contrast, the calendar life of LiFePO4 cells is not affected by being kept at a high state of charge

http://en.wikipedia.org/wiki/Lithium-ion_battery#Cell_life

So, yes, batteries DO degrade over time (Storage does degrade them) and there is nothing that can be done about it other than storing the batteries in a cool dry place. Storing the batteries "in" the computer is not an issue, as the same degradation will be experienced outside the computer.

ClickRight is correct, around a 40% battery charge is best for extended storage because there is less electrical potential, thus less leakage current between cells, thus less deposits are formed in the electrolyte over time.

 

[l337]

appreciate the replies guys

 

[Bobbing]

At my government job I repair scanners. In the hand held scanners we use batteries that are the same as the ones used in laptops (CR18650).
Periodically I have to test and recondition the batteries with a battery analyzer. Over the years I have found that it does not matter if I leave the batteries in the charger or on the shelf. They degrade the same over time.

 

[lewisg]

There has been a long debate about caring for laptop batteries but this is a simple way on how I do things. When I would be storing the battery, I make it a point to get it to full charge. I just plug it in or charge it when it only has 10 percent of power left as that avoids memory problems, though people say that they non existent with lithium ion cells.

When the battery is hot, the rate at which discharges, becomes higher for some reason. And, you might want to cycle it in between months to get its power back.