Re: OT : How best to prolong iBook battery longevity (not Debian specific)
On Mon, Dec 30, 2002 at 05:00:09PM -0700, Chris Tillman wrote:
> On Tue, Dec 31, 2002 at 10:40:22AM +1100, Tim Bateman wrote:
> > Sorry this is slightly off topic but given recent discussions re iBook
> > battery life I though this is worth asking here given the technical
> > knowledge of the audience.
> > So should I keep the battery topped up or deep cycle recharge ?
> In general for any battery, deep cycling will provide the longest
> life. For the iBook batteries, many have been found defective and
I was under the impression that Li-Ion batteries had a serious adversion
to deep discharges. Something about coroding the anode/cathode and not
being able to recover the charge. If somebody is brave they can test it by
checking the max_charge in /proc/pmu/battery_0 before & after a deep
I seem to remember loosing ~200mAH off my old battery from one deep
discharge, but the battery was allready performing at less than half
capacity anyway so it may have just been a fluke.
> will start to be unable to supply enough power to run the machine
> after reaching a 30, 50, or 80% charged state. That's probably why you
> read that it should not be allowed to fall below a certain number;
> many have found these batteries have a 'cliff' they fall off at some
The "cliff" is normal Li-Ion behavior, though if it's happening before 0%
the monitoring circuit is miscalibrated.
> point. If you have one of those batteries, probably nothing you do
> will help extend the life :-) but as a workaround, the advice is to
> get it charging before the cliff approaches.
> Someone said perhaps Apple was willing to supply a new, improved
> battery; I don't know the details.
Once they were convinced it was a hardware problem they promptly replaced
The max_charge on the battery I've had for the past couple months was 4189.
With me avoiding deep discharges it's still 4188.
- Nick Lopez
As for replacing the firewall...you really need to get rid of the
idea that a firewall is some magic security dust. It is nothing
more than a router with an attitude.
- gclef on /.