Laptop battery useage

[Michael Hipp]

> From: "Ronnie Gauthier" <ronnieg at chartermi.net>
> "Michael Hipp" <michael at hipp.com> wrote:
> > Generally on Nicad and NiMH batteries it is best to do a full discharge 
> > once and a while. Helps prevent that so-called "memory effect".
> 
> Have you ever seen a battery take a memory set outside of an industrial 
> setting?

Yes. Frequently. Almost predictably. The old Nicads were especially bad about this, NiMH seems quite a bit more forgiving.

> Not likely. Here's why. To take a memory set a battery needs to be 
> discharged to
> the same level each time and then recharged to the same level. After repeated
> cycles of this the battery gets lazy and only uses from the discharge level
> to the charge level. This usually happens when someone makes their own 
> automatic
> charging system and the bottom control and the top control are hard set and 
> not
> random within a range.

I won't pretend to be any kind of expert on battery chemistry, but this does not jibe with the emperical data. Especially on Nicads, the memory effect will begin to show itself after only a few cycles of incomplete discharge. (Born simply of a desire to not let the batteries run down on that beloved cell phone, laptop, music player.) The same is true of NiMH but to a lesser degree.

I don't know anyone that's built their own automatic charger. Well, other than that industrial charger manufacturer that I wrote all that embedded PICmicro code for a few years ago. Most of those batteries were gel or liquid lead-acid.

> If a Ni battery is overcharged you in effect "recondition" the battery.

NIcad or NImh? I've always heard this but never been able to make it work in the real world. The only way to recondition them was in the trash can (er, recycle bin) :-)

Michael