Yousuf Khan wrote:
I realize this is not really a homebuilt PC question, but it is a PC
hardware question. I got a laptop that doesn't seem to charge its
battery while it's running. You need to completely shutdown the machine,
and leave it plugged in, and it'll recharge only then. If you are
running the machine with the cord plugged in, and if the charge is
anything below 100% charged, it will say that it's charging, but it
actually keeps losing its charge (for example, you might see it going
down from 75% to 74%, etc.). It will not charge while the machine is
running. Is this a problem with the power brick, or is it something
within the laptop circuitry itself, do you think?

Yousuf Khan

A couple questions:

1) Are you using an "Ebay adapter" instead of the
original adapter ? Did the original adapter have three
contacts (maybe a TRS barrel), while the current adapter
has only two contacts ? If so, the laptop cannot
read the properties of the adapter. This happens on laptops
that come in two models, and one of the models uses a
"high power" adapter. The models make sure the adapter is
correct for the job, by checking the ID.

2) Is the battery a replacement battery, perhaps
lacking the same fuel gauge as the original ?
But that's a stretch.

I'd pick (1) before I'd pick (2).

And it could easily be a defect in the
charging circuit. I don't have a collection of such
circuits, so I cannot begin to give a breakdown on
what modes they've got and how they're controlled.
I presume there's a management IC for this purpose
(figuring out when to charge, checking charger
voltage or current flow).

Paul