[TriLUG] Linux laptop battery

[al johson]

"Please note this does not work for the newer Lithium batteries.  Those
batteries you should never run till dead"

You should also NEVER run Ni-cad or NI-MH batteries until they are dead
either!! If you do, you will risk reversing the polarity of one of the cells
and the battery will never recharge properly again. (a battery is composed
of many cells which are wired together--thus when you cannot recharge the
battery to its proper voltage this usually means one of the cells has
reversed itself, which will in turn actually slowly destroy the OTHER good
cells over time!). So if you recharge a battery and don't get back its
nominal voltage, it's probably time to replace that battery.
    Actually, if you're trying to cure a NiCad battery "memory" problem, you
should be aware that this problem actually never occurs ON EARTH!! (but it
is a serious problem in space). Memory problems are created on satellites
because they go through very regular charge and discharge cycles which never
happen on earth. (I have a paper from a NASA engineer if you need proof of
this).
    You should also ideally never keep a ni-cad battery on anything other
than a "trickle charger" (vs. a "fast charger") CONSTANTLY.
    Rechargeable batteries are actually very complicated and not as simple
as they seem. There are very great differences between Ni-Cads and NiMH
batteries, although both are rechargeable the Ni-Cads can be recharged
successfully more times than NiMH's. NiMH batteries do have two great
advantages over Ni-Cads. First, they have slightly higher voltages and much
higher current capacities. However, the price you pay is that the NiMH will
not recharge as many times as a NiCad. If you want to keep your batteries
well charged and give them the longest life possible, NEVER FAST CHARGE
THEM!! Slowly and gently is the watchword for a long battery life. You can
tell if you have a slow charger if it takes at least overnight to recharge
the battery. You always have to "pay extra" for fast chargers, and not just
for the chargers which are invariably more expensive than "trickle
chargers". If you're willing to pay the purchase price of more batteries
purchased over the life of the equipment, then fast chargers are for you.
Just remember that just like everything else you will pay more for this
convenience.
Finally, don't believe everything you read about batteries, even if the info
comes from the battery manufacturers. Remember that both you and the battery
company have two different goals: you want your batteries to last forever,
while the battery company would rather your batteries DIDN'T last forever.
    There is, however, one trick that definitely works if you're using
disposable alkaline or ordinary dry cells.  You can buy them when they are
on sale, double-seal them in plastic and put them in your freezer, where
they will keep for a few years until needed. Do not drop these frozen
batteries on any hard surfaces, however, or you risk breaking them
internally. This tip doesn't apply to rechargeable batteries to my
knowledge.
     Having totally discharged (and destroyed) more batteries than you can
imagine, I speak from experience when I say that you should never TOTALLY
discharge any rechargeable battery.
     I do own a NiMH and NiCad charger which PARTIALLY discharges these
batteries to a precise point before recharging them, but it has circuitry
which measures the temperature of the battery as well as  measures the
precise point at which the battery can be discharged before being damaged.
This is NOT something you can do without these sensors! In other words, it
is smart to slightly discharge a battery before charging but only to a very
precise point. Go beyond that point and you will either kill or severly
shorten the life of that rechargeable battery. Trickle chargers (as the name
implies) trickle the current into the battery in such a slow rate that they
never overheat or overdischarge the battery. By using such a low charging
current, the battery is automagically protected.
      HAVE MORE FUN WITH YOUR BATTERIES BY PAMPERING THEM!!!
AL