Computer battery

[micromass]

Hello all! :smile:

I have recently bought a new laptop. A problem that I had with my older laptops were that the battery broke quite fast, and I don't want this to happen anymore.

I have a 9-cell Li-ion battery, what do I have to do to let this battery live as long as possible? Is it prefered to work with the computer plugged in all the time, or is it preferable that I let the battery run empty every time and only then reload it?

Any advice is welcome!

[Bill Simpson]

One of the PC magazines, maybe PC World?, had an article on exactly question this last year. Unfortunately I don't recall the exact name or issue. It claimed that any particular model of battery has a life of n discharge/charge cycles. I am assuming that means you don't really abuse the battery and that we don't really know what n is for any particular battery. If they are correct then this probably roughly means that every time you run it almost down and recharge it then you used up one of your n, half way down and back up then you used 1/2 of one of your n, run it mostly only while on the charger and have it shut off when carrying from one place to another uses up roughly zero of your n.

It would be nice to find some other credible source that would agree with them.

[I like Serena]

It depends on the type of battery and the type of charger.

A car battery will be broken if it reaches a completely uncharged state.

But the first mobile phone batteries needed to be unloaded completely and recharged completely to lengthen their life span.

Modern chargers are smart and can actually unload and reload a battery to increase its life span.

As for a Li-ion battery, the best source I currently have is the wikipedia article, that says it loses 20% capacity per year if it's fully loaded and almost none if it is 50% loaded.
It doesn't say what happens if it is unloaded completely.

[MATLABdude]

This article agrees with what I've observed over the years:
http://www.techatplay.com/?p=61

Lithium ion batteries have a finite number of charge cycles, but they also age:
http://batteryuniversity.com/learn/article/how_to_prolong_lithium_based_batteries

Unfortunately, your battery doesn't just finish charging when it's done--it keeps getting 'topped off' when your adapter is plugged in (thus burning up charge cycles, and sometimes quite rapidly, depending on battery chemistry). So if you rarely ever use your battery, your best bet is to let it (dis)charge to around 40-50%, pull it out and top it off when you need to take the show on the road (keeping in mind the fact that it ages). If you use it more frequently, just let it charge up and pull it out of the laptop whenever you're on AC power.

The new Macbook Pros have built-in batteries (mine is one of the old ones with a removable/replaceable battery)--despite this, Apple says that their batteries should last 1000 (full) charge cycles before depleting to 80%:
http://guides.macrumors.com/Laptop_Battery_Guide