Laptop Batteries?

[noparlpf]

How long should a laptop battery last before needing to be replaced? Assume moderately heavy use, mostly kept plugged in at the desk.

[factotum]

Do you leave the laptop plugged in even when you're not using it? If so, you'll probably wreck the battery in a year or two--they don't like being constantly at full charge. However, you'll have to define what you mean by "last"--usually, the amount of time the battery will give you on a full charge gradually reduces over time, so how long the battery lasts depends on how long you actually need it to power the laptop for. As an example, the battery in my five-year-old Dell laptop will maybe give me half an hour of unplugged usage from full charge (was more like 2 hours when it was new), but since I never need more than that I don't consider it a problem.

[KuReshtin]

back in the day (about 10 years ago), computers had a built-in application to 'recondition' batteries that would completely discharge the battery, then recharge it and repeat that 2 or 3 times in a row.
It was a widely used tip when I worked at the laptop support to do that at least once every two or three months to keep the battery at best capacity, and if you did that, it should keep a decent charge for at least a couple of years.

not sure how viable that is with today's laptops with any advancement in battery technology, though, but it can't hurt.

And, like Factotum said, keeping it constantly plugged in isn't the best thing to do with a battery. Batteries nee a complete discharge every now and then to stay healthy.

[Flickerdart]

Modern computers have a battery life extender feature that prevents the battery from charging to full, which keeps it from losing charge. You'll see more loss of capacity from discharge/recharge cycles than anything else.

[The Rose Dragon]

My current battery lasted about five years before dying (it can still be charged, but it randomly shuts down while the computer is running on battery power before needing to be turned on again). I should probably buy a new one, but since I use the iPad while on the move, and the battery is only relevant for when I'm carrying it inside the house from one room to another, I am not exactly prioritizing it, and just keep the battery removed most of the time.

((For reference, my laptop is about six and a half years old.))

[Cat Dungeon]

Do you leave the laptop plugged in even when you're not using it? If so, you'll probably wreck the battery in a year or two--they don't like being constantly at full charge.

:smalleek:

Well that just blew my mind. Thanks. I just unplugged my laptop after reading this.

[Mando Knight]

Li-ion batteries, such as used in practically all laptops today, don't behave like NiCd or NiMH batteries, and the relatively complex charge circuitry also prevents overcharging, and the circuitry won't let you completely discharge the battery (which could make it unrecoverable).

It isn't healthy to store the battery at full charge, but if you frequently need to use the battery's capacity, you aren't storing it at full charge, and conversely if you don't discharge the battery that frequently, you probably won't even notice the loss of battery life until you're considering replacing the device itself.

[AdmiralCheez]

My current laptop battery has been going strong for about four years with no significant reduction in battery life. I typically leave it running 24/7 while plugged in (probably not the best idea, though).

The only reason I had to replace the last one was because it exploded during use. Made the whole laptop jump about an inch off the table; thankfully it was not on my lap at the time. I'm still not entirely sure why it exploded, but it bent the metal casing of the battery, so it was one heck of a bang.

[Snowbluff]

Modern computers have a battery life extender feature that prevents the battery from charging to full, which keeps it from losing charge. You'll see more loss of capacity from discharge/recharge cycles than anything else.

My father is a programmer, and this is what I've been taught. Seconded.

[Mando Knight]

The only reason I had to replace the last one was because it exploded during use. Made the whole laptop jump about an inch off the table; thankfully it was not on my lap at the time. I'm still not entirely sure why it exploded, but it bent the metal casing of the battery, so it was one heck of a bang.

Overheated or overcharged (the latter shouldn't be possible with most modern Li-ion chargers, but you never know). Laptops run hot anyway, so investing in better cooling systems and always keeping your machine properly ventilated are good ideas.

[thubby]

3-5 years seems to be pretty normal.
what happens is that every time the battery charges, the chemical reaction responsible creates a few of the wrong ions. these dont contribute to your battery's power generation so it eventually becomes less and less useful.

partially charging batteries also causes more of these useless ions

in most rechargeables (lithium-ion) it's reversible with high voltage that people don't have easy access to or the knowledge to use safely. refurbished batteries are at worst batteries that have been subjected to this process, they're chemically identical to new.

at home, the only time the proper differential exists to pull this off is when the battery is totally un-charged. that's why charging and draining the battery rapidly can "retrain" a battery.

[Mando Knight]

at home, the only time the proper differential exists to pull this off is when the battery is totally un-charged. that's why charging and draining the battery rapidly can "retrain" a battery.
Li-ion doesn't behave that way. NiCd may need to be reconditioned like that occasionally, but Li-ion doesn't lose its capacity by partial charge/discharge cycles, but rather as a gradual process from having a charge.

[thubby]

Li-ion doesn't behave that way. NiCd may need to be reconditioned like that occasionally, but Li-ion doesn't lose its capacity by partial charge/discharge cycles, but rather as a gradual process from having a charge.

they're less prone to it, but the only difference is which side of the cell the toxic ions exist on. the fix is the same, the chemistry is a little different.