Dell battery health gauge LEDs

I can't tell exactly what the LEDs are showing...
On a fully charged battery, pressing the button yields this...
press & release -> All 5 LEDs light up - then go out
press & hold -> All 5 LEDs light up - then blink out - then all 5 blink on -
then stay off -
-----------------
From the Dell site -

Most Dell batteries have an LED indicator that allows users to see how much
run time and how much overall battery life are available at the touch of a
button.

To check battery charge, press the button and the number of lights that
appear will tell you charge status. If all lights appear, you have a fully
charged battery. Each light that appears accounts for approximately 20%
charge.

To check the battery health, press and hold the status button on the battery
charge gauge for at least 3 seconds. If no lights appear, the battery is in
good condition and approximately more than 80 percent of its original charge
capacity remains. Each light represents incremental degradation. If five
lights appear, approximately less than 60 percent of the charge capacity
remains, and you should consider replacing the battery.

--
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"If everything seems to be going well,
you have obviously overlooked something." - Steven Wright

Hi!

> I can't tell exactly what the LEDs are showing...
> On a fully charged battery, pressing the button yields this...
> press & release -> All 5 LEDs light up - then go out
> press & hold -> All 5 LEDs light up - then blink out - then all 5 blink
on -
> then stay off -

I followed the Dell instructions that involved holding the button down for
three seconds with the fully charged battery from a Latitude D800. The
battery was sold with the system in March 2005. This battery claims to have
29% wear when queried by various software tools (one of which is Notebook
Hardware Control).

When held down, all of the lights come on to indicate current charge level,
and then they go off. Right at three seconds of holding the button down, one
appears for a moment, and it goes off. If this is used as a wear indication,
it would seem to be roughly correct, provided that each LED indicates 20%.

So I just went and got my second battery, which reports 41% wear. When
tested the same way, all of its lights came on. Hmmm. I popped it in the
computer and found it to be less than 100% charged. Perhaps all five lights
indicate a less than full charge? I'll post back in a little bit when it has
finished charging.

William

Well, several hours later I finally came back to it. It seemed like that
battery was diddling around, spending forever at the 99% charge level.
Finally it topped off.

And it still behaved the same way, which is to say that all five LEDs lit up
for a moment and then went out after holding the button down for three
seconds.

Something tells me that different battery suppliers may have implemented
this test differently than Dell thought they did...or something else is
going on.

The battery pack that responds as expected in my system was made by Sanyo
and identifies itself as a "DELL 7P0665 1807SanyoDELL 7P0665" battery.

The other one (that shows all the LEDs after holding the button) is a
Panasonic that returns the following information: "DELL W1955
1407PanasonicDELL W1955"

For whatever it might be worth...

William

In news:JQpnl.523957$TT4.177450@attbi_s22,
William R. Walsh typed on Fri, 20 Feb 2009 03:55:21 GMT:
> Well, several hours later I finally came back to it. It seemed like
> that battery was diddling around, spending forever at the 99% charge
> level. Finally it topped off.
>
> And it still behaved the same way, which is to say that all five LEDs
> lit up for a moment and then went out after holding the button down
> for three seconds.
>
> Something tells me that different battery suppliers may have
> implemented this test differently than Dell thought they did...or
> something else is going on.
>
> The battery pack that responds as expected in my system was made by
> Sanyo and identifies itself as a "DELL 7P0665 1807SanyoDELL 7P0665"
> battery.
>
> The other one (that shows all the LEDs after holding the button) is a
> Panasonic that returns the following information: "DELL W1955
> 1407PanasonicDELL W1955"
>
> For whatever it might be worth...
>
> William

I've seen these LEDs on many laptop batteries and they are supposed to
represent the charge level of the battery. Basically all they are a
crude voltage gauge. They are okay for crude, but I wouldn't take them
too seriously. As I have seen some show 50% charge left, but under a
real laptop load, won't even power up the laptop without recharging them
first. They should work fairly well to test a battery on the shelf
though. As once it gets really low, it is time to add some charge to
prevent them from going too low and cause permanent damage to the
battery.

--
Bill
2 Gateway MX6124 - Windows XP SP2
3 Asus EEE PC 701G4 ~ 2GB RAM ~ 16GB-SDHC
2 Asus EEE PC 702G8 ~ 1GB RAM ~ 16GB-SDHC
Windows XP SP2 ~ Xandros Linux - Puppy - Ubuntu