Hi,

Sadly, I've got a HP pavilion dv2 laptop here that was left with the
lithium battery almost empty for too long (maybe 2 to 4 weeks?), to the
extent now it doesn't charge normally. The battery was operating
normally before that, no signs of reduced capacity. The only thing
leading to this seems to have been that it was left at 0% for too long.

A HP battery test tool (Windows only, I wonder if I can get the same
information under linux, maybe it's in the verbose output of the acpi
utility?) reports that part of the time the voltage is increasing (still
well below design voltage, around half of it), but sometimes it will
also decrease. I suppose this means sometimes the battery is being
charged, but not always.

Does anyone have any idea of how do HP laptops implement the bootstrap
charging process? Is there some secret handshake to initiate this in a
way that goes on until the battery can be charged normally? Or are
voltage drops part of the bootstrapping charge process too?

The battery is removable and if I do that, it'll go back to slowly
increasing voltage values, but this is still sub-optimal as it requires
constant supervision, to avoid too much of a drop.

On 11/8/24 03:47, Nuno Silva wrote:
> Hi,
>
> Sadly, I've got a HP pavilion dv2 laptop here that was left with the
> lithium battery almost empty for too long (maybe 2 to 4 weeks?), to the
> extent now it doesn't charge normally. The battery was operating
> normally before that, no signs of reduced capacity. The only thing
> leading to this seems to have been that it was left at 0% for too long.

How old is the battery aka how long in use?

>
> A HP battery test tool (Windows only, I wonder if I can get the same
> information under linux, maybe it's in the verbose output of the acpi
> utility?) reports that part of the time the voltage is increasing (still
> well below design voltage, around half of it), but sometimes it will
> also decrease. I suppose this means sometimes the battery is being
> charged, but not always.

In PCLinux you can get current battery information via the CLI of
course but we have a battery widget on one of my panels that gives
the current state and whether charging or discharging..

Have you downloaded the manuals that should be available on the
HP web site?

>
> Does anyone have any idea of how do HP laptops implement the bootstrap
> charging process? Is there some secret handshake to initiate this in a
> way that goes on until the battery can be charged normally? Or are
> voltage drops part of the bootstrapping charge process too?
>
> The battery is removable and if I do that, it'll go back to slowly
> increasing voltage values, but this is still sub-optimal as it requires
> constant supervision, to avoid too much of a drop.

Might be best to buy a new battery. Of course I did that with
my Dell Latitude 7450 and I bought two and one was bad so good luck.

bliss