HP Omnibook battery calibration and wiring questions

[Guest]

Archived from groups: comp.sys.laptops (More info?)

The HP Omnibook 6000 has a battery calibration utility, or Smart Battery
Auto-Learning. Press F6 when it boots.

I'm trying to figure out what this utility does. I can't find any
information in the documention.

I'm running this utility now. It seems to be discharging the battery, I
suspect to measure its capacity.

Once this capacity is measured, where is this information stored, in the
BIOS or in the battery? If it's in the BIOS then this could cause
problems when I use a different battery, right?

Also, does anyone know anything about how these batteries are built
(wired)? I tore my 6-cell battery apart. It's got 3 (parallel) pairs
of li-ions in series. That should give a nominal 10.8 volts (3 x 3.6)
However it also has a wire that taps midway (2/3) in the series. What's
this wire for?

And do the 8-cell battery packs put out 14.4 volts?

Thanks for your help.

 

[Guest]

Archived from groups: comp.sys.laptops (More info?)

"Bruce W.1" <sorry@noDirectEmail.com> wrote in message
news:3ltXd.18159$hU7.9067@newssvr33.news.prodigy.com...
> The HP Omnibook 6000 has a battery calibration utility, or Smart Battery
> Auto-Learning. Press F6 when it boots.
>
> I'm trying to figure out what this utility does. I can't find any
> information in the documention.
>
> I'm running this utility now. It seems to be discharging the battery, I
> suspect to measure its capacity.
>

Correct.

> Once this capacity is measured, where is this information stored, in the
> BIOS or in the battery? If it's in the BIOS then this could cause
> problems when I use a different battery, right?
>

It is stored on the Smart Battery manager chip inside the battery pack. It
is necessary for this to be periodically calibrated. In most laptops this
can only be achieved by periodically discharging the battery to its cut-off
point (roughly 1 discharge in 30 ought to do it). This information is
rarely in the handbook, presumably so that a battery can appear to be
knackered before it really is.

> Also, does anyone know anything about how these batteries are built
> (wired)? I tore my 6-cell battery apart. It's got 3 (parallel) pairs
> of li-ions in series. That should give a nominal 10.8 volts (3 x 3.6)
> However it also has a wire that taps midway (2/3) in the series. What's
> this wire for?
>

Dismantling batteries is not a recommended practice unless you know exactly
what you are doing. Have you seen what a Li-ion can do if it is damaged?
It is not possible to extinguish the fire.

The extra wire is most likely for circuits inside the laptop that require a
lower voltage. This means that some of the battery will be discharged
before the rest.

> And do the 8-cell battery packs put out 14.4 volts?

Probably. I have a 9 cell pack that is 11.1 volt (slightly higher 'cause
they are Li-ion-Polymer). It all depends on how the cells are wired. They
are never a simple series stack because the charge circuit need to monitor
the cells much more closely.
>