Acer Swicth battery drain when shut off

billsey

The I²C bus is part of the motherboard, it's typically used to allow different low speed subsystems to talk to each other via a serial connection. It allows them to not tie up high speed transactions, such as memory to processor, with low speed tasks (like keyboard to processor). I'd guess that it would show up in Device Manager among the System devices (might also be called SMBus if Intel chipset) and if you find the right device you can probably disable the most active power modes. I don't have a W4 handy, so can't figure out which device it is... My W700 uses a completely different chipset.

Spabel

Hey, thanks for your reply. I can find the device in device manager - that's where I see that it is in power mode D0. The problem is that there are not options anywhere to change this to a low power option.

 

I'm not in front of the unit right now, but I will post back images of the device manager screens later. I really hope that by doing this Acer can do something about the problem because their technicians on the Acer Support were not able to help atl all

 

By the way, I lose a 100% charge in a few hours (such as over night) in connected standby. So bad that the device cannot be used day to day. If it's 100% now and I let it sleep until tomorrow morning then I won't be able to use it because the battery would be depleted! That's totally unacceptable! The interesting thing is that sometimes (yes, just sometimes) after a reboot this won't happen and it might survive a few days on the charge. I'm convinved this is a driver / firmware issue...

Spabel

Here's the I2C controller on the device manager (marked in yellow) and the power details:

 

Here is the output from my sleepstudy report showing that it is the culprit:

 

Can anyone plleeeeaaasseee give me some assistance with this?

billsey

Yeah, definitely looks like a driver problem to me... Note that the D3 state is supported (PDCAP_D3_SUPPORTED), but S3 (sleep state with lowest power usage) isn't mapped to D3 as it should be. Hopefully someone at Acer is watching this thread (they normally do watch) and can request a driver update from the I2C vendor (likely Intel). In the mean time, plug in overnight when possible, or do a full shutdown when idle.