On Thu, 13 Jul 2006 22:51:03 -0500 Jay C Vollmer <[EMAIL PROTECTED]> wrote:
> On Thursday 13 July 2006 21:24, Carl Fink wrote: > > > I'm not an electrochemist, but modern Li-ion batteries don't develop > > memory, they just lose capacity each time they're charged. > > Isn't what you're describing 'memory?' > The end effect may be similar in terms of degraded performance, but the chemical point of view is different. I don't remember the specifics, but IIRC NiCad develop a 'memory' in that the material 'remembers' it's charged state and won't discharge. It is recommended to completely discharge these batteries on occasion to avoid this. Li-ion don't have this effect, but on the other hand they don't like to be completely discharged. The problem is that they have several cells, and some discharge faster then others. When some of the cells completely discharge and others haven't yet, an effect of back-flow occurs which burns out those cells. There is another problem with all batteries, (a problem of the charging circuits actually) that if they are charged too fast they will over heat which damages them. The second problem is that none of the batteries like to be over charged, something which usually isn't handled properly either usually. The integrated circuits may get out of sync with the battery (usually when the battery degrades with age and the circuit isn't calibrated any more, which causes false information, but doesn't effect performance). It is sometimes recommended to discharge the battery completely when that happens to recalibrate it, but isn't recommended on a regular basis with Li-ions. -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]