power consumption after shutdown
mikus at bga.com
Sat Feb 14 13:56:22 EST 2009
Chris Ball and Paul Fox responded:
> > I take this to mean that *something* was draining some power for
> > the two days the XO was sitting in its "shut down" state.
> The embedded controller was. Something needs to be watching for a power
> button press in order to know when to turn on.
Thank you. I guess it's simpler to do it that way, than to add two
extra "latches" to the package. [2 latches might work as follows:
One latch would be turned on when sent electricity through the power
button. This first latch would turn on the second latch if that
second latch was off. The software could test the first latch
state, and could turn that state off when it wanted to be watching
for a power button press.
The second latch would connect the battery to the motherboard
proper. It would be turned off by the software for "zero power
Benjamin Schwartz wrote:
> All rechargeable batteries lose stored energy over time.
> This phenomenon is called "self-discharge".
I have found the XO-1 batteries (mfg by BYD Company Ltd) to be very
stingy with energy loss. When I put one back in after a month out
of the case, the XO software told me it was still 94% charged.
James Cameron mentioned measuring a current draw of 24mA. I suspect
this was *not* on a thoroughly "shut-down" G1G1. In my experience,
after two days in a "shut-down" state the XO software shows the
battery charge % to be somewhere in the mid-90's.
> If you wish to avoid this draining by the EC, and instead rely only on
> draining by self-discharge of the battery pack, then remove the pack
> from the XO. Self-discharge rate has a dependency on storage
> temperature as well.
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