Before I reply, I'd like to say that I'm not trying to argue (I hate forum arguments, or arguments in any setting), but just trying to make a point that something which I asked would be useful to me, and perhaps to others that use their laptops in a similar way (plugged in just about every second it's on).
I realize the inevitable decay of batteries, and I'm not going to try to argue against it. I've had batteries decay and go bad on me. Yes, no battery will last forever. However, from everything I've read about prolonging the shelf-life of Lithium Ion type batteries, I think I can get maybe 1 or 2 more years out of it by keeping it at a lower charge level. Since in my case, it's just about always plugged in, I'd like these couple extra years. A point to add is that the recommended charge level to store lithium ion batteries at is 40% (not my number, but is from just about every source I can find). My battery is being "stored" (not actually being used, just sitting in my laptop while it's on A/C power) almost all the time.
Basically my whole reason for doing this is to get an extra 1-2 years out of a battery before replacing it, because that matches up better with how often I buy a new laptop. Not having to shell out $150 for a new battery (darn those expensive suckers) for each laptop would be nice.
At a 100% charge level, a typical laptop battery that is full most of the time at 25 °C or 77 °F will irreversibly lose approximately 20% capacity per year.
And a typical Lithium Ion battery (the kind my laptop uses, and I believe are very common in them) that is kept at 40% charge at 25 °C will irreversibly lose approximately 4% capacity per year. Jump the temperature up to 40 °C (closer to laptop temp, in my opinion) and a 100% charge loss is at 35%/yr, and a 40% charge loss is at 15%/yr.
That said, does anyone know of just a utility I asked for in the first post?
Edited by Anomaly, 12 November 2009 - 03:13 PM.