On Mon, 15 Aug 2011 16:21:45 +0100
John Williamson wrote:

Davey wrote:
On Sun, 14 Aug 2011 21:49:59 +0100
Roger Mills wrote:

My 8-year-old HP/Compaq nx9005 laptop has got a completely flat
battery
- or, rather, *two* completely flat batteries, because I bought a
new one a few years ago and they are now both the same.

The power arrangements for this laptop are as follows:

The battery is lithium-ion, 14.8v, 4400mAH (type F4809). It has a
row of LEDs on the side to indicate the state of charge.

The mains power supply delivers 18.5vDC through a cylindrical
connector, which powers the laptop when on mains, and charges the
battery via circuitry built into the laptop. There is a light on
the front of the laptop which is amber when the battery is
charging, and turns green when it is fully charged.

Well, that's what's *supposed* to happen. What *actually* happens
is this:

If I 'charge' the battery for (say) 24 hours, the lamp is amber for
the whole time and never turns green. If I remove the battery
immediately after 'charging', it is stone cold and none of the
charge indicator LEDs light when the test button is pressed.

Even after a long charging period, the battery won't start the
laptop if mains power is not present. If when the laptop is
running, mains power is removed, it stops dead.

If I run the laptop without a battery present, the charge lamp
flashes amber (but is solid amber if a battery is present).

I have tried putting one of the batteries in the freezer for 2
days, and then thawing it and attempting to charge it - all to no
avail.

Sorry for the long pre-amble! My question is this:

How can I tell whether the problem lies with the battery or with
the internal charger? Are there any clues in what I have written
above? I don't mind buying another new battery but, if the charger
is duff, I will have wasted my money.

I usually run it on mains anyway, so it's not a total disaster if
I can't make the battery work - but one does tend to expect a
laptop to have its own built-in UPS!

TIA.

I have a similar situation to you. My laptop is an nx9010, and I
bought a new replacement battery just over a year and a half ago.
Now it behaves exactly as you describe, in every detail, and I also
have wondered whether it's the battery or the charging system. I
shall be interested in the conclusion, if any, although I have
bought a new laptop, which far outstrips the abilities of the
Compaq.

Something I have noticed on my Armada is that aftermarket batteries
are very variable in quality. I bought a pair, so I could put one in
the CD drive slot, and one in the normal slot, one lasted a year or
two, the other failed totally within weeks.

The both gave symptoms as described when they failed, with the bonus
that one generated a BIOS error message saying the battery was faulty.


All I got was the information that it was almost fully charged, but it
wasn't.
The fact that the LED is alight does tend to indicate that the charging
system is functioning, rather than the battery. But is could also be
that the system is overcharging the battery, leading to its early
demise.
--
Davey.