[Thinkpad] 560x: battery problems on bootup?

I'm having some trouble with a Thinkpad 560X I bought recently. It seems to
work just fine, but it does something strange (and not always) when
attempting to boot on battery power.

I think it may be a tired battery but I'm hoping somebody can confirm before
I run off and drop money on a new one.

Here's the details.

I've tried "forming" it by fully charging and then fully discharging it,
three times. It takes several hours for it to discharge with just the display
drawing power, so it's not as if the battery won't hold charge. That seems OK.

Now here's the problem. I seem to be having some trouble booting (but not
running) it on battery power alone, and thought maybe I'm doing something
wrong. I don't see what, as I should merely slide the momentary contact
switch forward and it should go, right? And indeed that's how it boots when
on AC power.

With the battery fully charged, I'm able to fully shut down (using the
Windows Shutdown from the Start menu), and reboot, many times in succession.
As long as I don't wait too long.

If I wait more than a few minutes after shutting down, sliding the switch
forward results in a brief noise of hard drive starting, then it stops. Two
lights flash momentarily on the monitoring array of LEDs and then all the
LEDs are dark again.

Now, here's the strange part. If I plug in the AC unit just for a second
while booting up, certainly not long enough to put any significant charge
into the battery, it will then boot up just fine, and then run for hours. I'm
talking really only one or two seconds -- long enough for the hard drive to
spin up. Then pull the AC plug even as it's booting, and it continues to go
through its bootup sequence just fine. It's as if it needs a push from the AC
to get over some sort of "hump" during bootup, and from then on everything is
fine. I don't think it's just the HD drawing power, as the HD will
automatically shut itself off after 3 minutes anyway the way I have it
configured now. And I am able to reboot from that condition, on battery
alone, if I do it soon. But if I wait a half hour or so, it won't boot from
battery.

Could it be that there are more things drawing current all at once during the
first two seconds of bootup, that never again all come on at the same time,
and the battery just can't pull that whole train? Monitor, CMOS, HD, who
knows what else...

Once booted up, I can have it running for three hours on battery, without any
heavy disc usage of course. Hard disk works fine too when needed, and shuts
down after the 3 minutes I set. Strange, huh? So the battery is holding
charge. But is this maybe a current delivery problem?

Is it something I'm doing, or signs of a tired battery?

I downloaded the manual from IBM's site but I can't find anything specific
addressing this.

If it's a tired battery, that's just part of the cost of keeping a notebook
running and I'll just have to get another. (I note that nobody guarantees
batteries in these things anyway). Unfortunately I don't know anybody close
by who has a "known good" battery I can try.

Thanks in advance,

Pete
PLALBRECHT@aol.com
_______________________________________________
Thinkpad mailing list
Thinkpad@stderr.org
http://stderr.org/cgi-bin/mailman/listinfo/thinkpad
Received on Tue Apr 22 15:26:58 2003