Power consumption

GoogleGroups
1

I am noticing that when the BBB is off but still plugged in its using
for the most part as much current

as when its running. I have not hooked up a ammeter to the supply yet
but the CPU is as hot as it is when running.

Has anybody done any testing to confirm this ?

Is there something that can be done to tell the PMIC to turn all power
off on halt ?

I can solve this with external circuitry but it seems that there is
something wrong.

2

How are you “turning it off” ?
Command line? what command?
Or some other way?
— Graham

3

I have found that with Debian 8.x
from the command line you have to send “shutdown -hP now”
If you send just “shutdown now” or “shutdown -h”, then it leaves the CPU running (Doing what, I am not sure.).
the -P option specifically tells it to turn off the power after the shutdown.

— Graham

4

just a shutdown now -h via the acpi I have a battery on the board too
so it shuts down
gracefully. and when power is reapplied no boot which is not a huge
issue but it still draws enough to keep the
CPU warm.

5

very interesting. thanks i will give it a try if i can figure out where
the command is issued from

6

Yes, interesting. Sometime ago I’ve added a lipo battery to test I could cleanly surive power outages. When I did shutdown the bbb the battery was flat after a few hours which made the lipo route unusable.
I then assumed the pmic still burned some power from the lipo even when the bbb was shutdown.

Now I wonder if this has to do with this issue?

7

Yes, interesting. Sometime ago I’ve added a lipo battery to test I could cleanly surive power outages. When I did shutdown the bbb the battery was flat after a few hours which made the lipo route unusable.
I then assumed the pmic still burned some power from the lipo even when the bbb was shutdown.

Now I wonder if this has to do with this issue?

Yes, it is very likely the cause.