[Gta04-owner] bq27000-battery: battery is not calibrated! ignoring capacity values

Bob Ham rah at settrans.net
Mon Feb 4 13:18:25 CET 2013

On Mon, 4 Feb 2013 17:06:54 +1100, NeilBrown <neilb at suse.de> wrote:

> Datasheets can be found.  e.g.
> http://www.ti.com/lit/ds/symlink/bq27200.pdf

Ah :-)

> There are two things that can cause this message.
> The first is if the BQ27000 in your battery doesn't think that it is
> calibrated.

I think this is the case.

> This seems unlikely except for a new battery or one that has
> been left to go completely flat for a long time.

My battery was from a GTA01 developer kit which, apparently, hadn't been
touched for years.  It was flat when I got it.

> Possibly we could get the BQ27000 driver to detect read errors better
> and somehow report "no battery" rather than "not calibrated".

It would be good if the driver reported more information about the state
of the BQ27000, for example the EDV1 and EDVF registers.  The EDV1 status
*flag* is read by the driver and exported through the
I am expecting this flag to be set.  However, I can't see how to check the

Apparently, the standard properties in the power supply interface are
exported through sysfs and uevent but I can't see anything related to
"health" under /sys/class/power_supply/bq27000-battery.  I also can't seem
to find any user space utilities to query the power supply properties.

> If a single discharge/charge cycle doesn't get rid of the "not
> message, then either:
>  - there is no bq27000 in the battery
>  - the bq27000 is broken
>  - the connection to the battery is dodgy.

I think you might be able to add to this list:

 - the battery is dead

Bob Ham <rah at settrans.net>

for (;;) { ++pancakes; }

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