[TriLUG] Linux laptop battery
Wed, 6 Feb 2002 03:27:18 -0500
Unfortunately, I read another message about "your laptop battery" and posted
a response about totally discharging rechargeable batteries (don't do it!!).
To respond to your question "what killed the battery?", I can only respond
with two answers: 1. either you used your laptop so much and recharged the
battery so many times that you just used up it's useful life---As I noted
earlier, you must remember that NiMH batteries have a shorter lifespan than
NiCad batteries (it's the price you pay for their higher voltage and esp.
current). OR it could be defective, although I doubt that it was if it
worked well for 12 months.
NiMH batteries should definitely be stored at room temp., as far as
being "drained", I suspect that means the battery should be discharged
(unless you're using a battery with liquid electrolyte, like a car battery
has!!) Remember, though, that this can kill good batteries. If you take a
wire and discharge just about any battery you will burn it up (and there
will be a lot of heat--even flashlight size batteries). Batteries should
always be discharged under a resistive load, but what the correct one is for
the battery in question is a difficult question without knowing several
figures. As I said earlier, the only place you should probably discharge
these batteries using them with your laptop! But if you discharge them too
long you can also damage them there!!
Actually, discharging batteries intentionally (when they are not in use),
is not a good idea because you risk the danger of "over-discharging" it and
reversing one of the cells (which would mean that that cell would actually
reverse its polarity!!). Now the battery manufacturers ship their batteries
totally discharged. Which is safe if you have the equipment (like they do)
to totally discharge it to the proper point. Batteries are still sort of
19th century devices and they should be treated as such. I would suggest
that you keep the battery out of the PC unless you are using it for power.
Second, you should keep it at room temp (or slightly cooler--cold slows down
chemical processes!). Finally, you should protect the connectors on the
outside of the battery by putting it in a plastic case or covering them with
masking or electrical tape (you can discharge a battery accidentally if the
smallest piece of metal makes a connection).
Still if you used it heavily for 12 months, you may have gotten the
useful life out of that battery (I can't say because that depends on how
long you discharged the batteries and how many times you recharged it (there
is a limit to the number of times NiMH batteries can be recharged and the
number is much smaller than NiCad batteries) --since you are in this elite
group, I suspect that you used it a lot!!). There are many battery
manufacturers which probably make a replacement battery for you to use. Get
the name and number off of it and go shopping on the web for a new one. If
you can't find a reputable company, let me know and I'll give you some 800
numbers which the amateur radio community uses to buy their batteries from.
Batteries do not last long if they are abused. You must not discharge them
too long before recharging them but on the other hand, if you charge them
too many times you can also cause problems. I'm afraid you'll have to use
trial and error to figure out the most efficient way of using your
batteries. But the next time you buy batteries, buy TWO of them. That way
you can use one in your laptop while the other is recharging in the charger.
(I'm assuming that you have a charger separate from your laptop--which may
not be valid).
Still two batteries can give you a spare if one of them quits working. If
you don't have a separate charger, leave the second one in the discharged
state that you received it until you need it. Finally, remember that NiMH
batteries have a much shorter lifespan than NiCads. Hope this helps
----- Original Message -----
From: M. Mueller (bhu5nji) <firstname.lastname@example.org>
Sent: Sunday, February 03, 2002 4:53 PM
Subject: Re: [TriLUG] Linux laptop battery
> Any ideas on what killed the battery? It's a NiMH that's <12mon old. Is
> the case of the mfr installing a crappy battery like auto mfr used to
> crappy tires?
> I saw on the WWW that perhaps I should have been running without the
> installed when I spend so much time on main power. Also it said that the
> battery is being stored it should be drained and at room temp. Does that
> make sense?
> Mike M.
> On Sunday 03 February 2002 04:41 pm, you wrote:
> > There is a very simple way to solve this problem. Simply find someone
> > has a battery that will work on your computer and swap the two
> > If the problems go away, Yes--your battery was bad!!
> > But I'm surprised that you don't have more than one battery
> > Here's why. Batteries are notoriously famous for dying just when you
> > them the most. Hence they should always be bought in pairs and they
> > be properly charged and discharged with the best charger you can afford.
> > have a list of 800 numbers you can call to purchase rechargeable
> > usually for less than you can buy them locally. Yes, there are companies
> > that not only sell nothing but batteries for computers, cellphones, and
> > lots of other things you probably don't need, AND even better there are
> > also some companies which can even REBUILD lots of the batteries that
> > used in portable computers, etc. Sometimes they can open the cases and
> > replace the batteries in them and you get new batteries in your old case
> > for just the cost of the new batteries!!
> > You simply call them on the phone and tell them the numbers on the
> > you want replaced or repaired. If you want this info, I'll be happy to
> > it for you.--AL
> > P.S. I have no financial interest in any of these companies!! The
> > know about them is that amateur radio operators use lots of rechargeable
> > batteries!!
> > =====================
> > ----- Original Message -----
> > From: M. Mueller (bhu5nji) <email@example.com>
> > To: <firstname.lastname@example.org>
> > Sent: Sunday, February 03, 2002 3:49 PM
> > Subject: [TriLUG] Linux laptop battery
> > > Can anyone help me determine if a laptop battery is dead?
> > >
> > > Symptoms:
> > >
> > > 1. Laptop runs no longer than 5 minutes without AC
> > > 2. cat /proc/apm gives this: 1.14 1.2 0x03 0x01 0xff 0x80 -1% -1 ?
> > > 3. apm -v gives this :
> > > APM BIOS 1.2 (kernel driver 1.14)
> > > AC on-line, no system battery
> > > 4. battery is installed
> > > 5. charging light goes out pretty quickly after being reinstalled
> > >
> > > Is there anywhere to go to get the battery checked?
> > > Is there a chance that I'll buy a new battery only to find out the
> > is
> > > faulty?
> > > It's not a Mandrake 8.1 problem or an APM problem is it?
> > >
> > > Thanks,
> > > Mike M.
> > > _______________________________________________
> > > TriLUG mailing list
> > > http://www.trilug.org/mailman/listinfo/trilug
> > _______________________________________________
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