How long do laptop batteries usually last?

[Turkish]

My HP's battery is about dead by now... 2,5 years old... it only lasts 7 minutes after full charge What about other people with old laptops?

 

[sciencewhiz]

LI-Ion batteries are only good for about 500 charges (or less). Thus, if you use it on battery every day, and charge at night, you only get 1.5 years. The battery on my thinkpad A21M lasted a year before I noticed degradation, and another year before it was to less then half.

I don't know what the number is for NiMH, but it's higher. But, you don't get the charge density associated with Li-Ion batteries, so they aren't used much in laptops anymore.

All batteries self discharge. Most laptops won't charge the battery unless it falls below a certain percent. Even so, it might charge the battery once a week. If all you do is use your laptop at the desk, you can remove the battery and it will last longer when you do use it.

IBM recommends storing a LI-Ion battery at about half charge.

 

[Bateluer]

Originally posted by: Xiety
My HP's battery is about dead by now... 2,5 years old... it only lasts 7 minutes after full charge What about other people with old laptops?

You should be able to get a new battery from HP easily enough.

 

[Derango]

usually around 1 to 1.5 years.

 

[Turkish]

Originally posted by: Bateluer

Originally posted by: Xiety
My HP's battery is about dead by now... 2,5 years old... it only lasts 7 minutes after full charge What about other people with old laptops?

You should be able to get a new battery from HP easily enough.

1 year warranty...

 

[dnuggett]

Most laptops won't charge the battery unless it falls below a certain percent. Even so, it might charge the battery once a week. If all you do is use your laptop at the desk, you can remove the battery and it will last longer when you do use it.

Not exactly.. most newer laptops will recharge a battery as soon as it is drained any amount. When you say last longer.. do you mean last longer per use or have a longer lifespan? Lion batteries do not suffer from the memory effect and will only last longer not shorter (per use) by leaving them plugged in the laptop. That is until the battery reaches it's useful lifespan (about 1 to 1.5 years with your math)

 

[WobbleWobble]

Originally posted by: dnuggett


Not exactly.. most newer laptops will recharge a battery as soon as it is drained any amount. When you say last longer.. do you mean last longer per use or have a longer lifespan? Lion batteries do not suffer from the memory effect and will only last longer not shorter (per use) by leaving them plugged in the laptop. That is until the battery reaches it's useful lifespan (about 1 to 1.5 years with your math)

Actually, as the battery gets older, it self-drains faster too. On my IBM ThinkPad, it automatically starts charging around the 95% mark. It will then needlessly recharge itself back to 100%. It's not the memory effect that's the problem, it's the limited number of cycles a battery can be charged. You will end up wearing out the battery cells at the end, shortening its capacity.

My IBM ThinkPad is just over 2 years old now. I took good care of the battery by not unplugging the AC or 5 minutes then plugging it back in or by not leaving in the battery and having the AC automatically recharge it. My battery life is still within 70% of its original life (estimate).

 

[dnuggett]

You will end up wearing out the battery cells at the end, shortening its capacity.

Exactly. That's why I stated until it reaches it's useful lifespan. What I would like to see is some testing or a datasheet showing what the effect is on recharging the battery after it has only drained say 20%. I am wondering if that is considered a cycle to the whole battery, a portion of the battery or if it is a % of a cycle.

 

[jschuk]

I have seen Li-ION batteries last anywhere from 9 months to 5 years. I don't know how the people used or stored them, but that is what I have seen. I would say that most Li-ION become worthless after two years (<20 mins). I have had customers who say they never use the laptop off of AC and their batteries go bad after 1.5 years. I know Li-ION aren't supposed to have a memory effect, but I usually recommend a full charge/discharge every 3-5 weeks. It can't hurt can it? I would also recommend taking the battery out if you never use it and don't need it as an UPS (i.e. no brown/blackouts). My own battery crapped out after a year. My wife and I almost always use that laptop on battery and most of the time run it down to 40-60% remaining, although it did get rundown to 0% from time to time. Now that battery only lasts about 30 mins and what it does is goes from reading 30-40% to 3% in one second. My previous laptop was also used mainly on battery and that battery worked fine for about 2-2.25 years although that one was run down to 0% more often.