On Wednesday 10 November 2010 18:05:40 Paul Hartman wrote: > 2010/11/10 Fatih Tümen <fthtmn+gen...@gmail.com>: > > On Tue, Nov 9, 2010 at 23:52, Paul Hartman > > > > <paul.hartman+gen...@gmail.com> wrote: > >> Hi, > >>
<snipped> > Last night I took it to full charge, put in memtest86+ boot CD and the > system lasted 9 minutes before battery was drained. So that matches > the 1/3 batter life I experienced under normal usage, too. > > I just read somewhere on WWW that sometimes better calibration can be > achieved by leaving battery completely drained for some time (more > than 5 hours) before plugging the charger back in. So I'll try that as > one last desperate hope. If the cells are dead then I can't do any > more harm to them so why not try it? :) If these are discharged too far (The circuitry in the battery-pack should prevent this) the cells can get permanently damaged. This seems to have happened. Best practices for batteries (any type, apart from Lead Acid ;) ) is to take them out of the laptop when running for long periods from the mains. This is to prevent the batteries from being constantly charged. > Now, since this is an old laptop (6 years) I am skeptical about buying > a replacement battery that may have been sitting in a stockroom for > several years. Local battery store wants more than US$100 for a "name > brand" replacement (Rayovac). Online, I can find one for less than > half that price, but I am really suspicious about the quality. My past > experience of buying generic laptop batteries online has not been > good. Don't fit properly, poor lifespan, etc. <snipped> If these batteries have been charged to 70% before storage, they can last a while, but one should still top them up to 70% once every year or so. > Has anyone tried to replace the cells inside their own battery? I'm > reading this site: > http://www.electronics-lab.com/articles/Li_Ion_reconstruct/ > > Seems kind of dangerous... I can't price the cells because I haven't > opened my battery pack, so I don't know if it's really any cheaper > than buying a new one. Actually, it is dangerous and I wouldn't trust the batterypack anywhere near my laptop after a procedure like that. If the soldering isn't done correctly, the battery-pack can literally explode when put under load. -- Joost Roeleveld
