Improving MBP battery life on Boot Camp
This question has been bugging me for a while now, and I have no idea how to solve it: How does one go to improve Battery life on an MBP under Boot Camp?
The context: My MBP is averaging 4 hours of battery lifetime when used for light browse, navigation and some YouTube consumption, and this is with ThrottleStop undervolting in place even! As an eGPU active user, I do take my laptop on the go. Most of my software requires Windows, but also I require macOS for specific purposes, and carrying a second laptop was not an option for me. For being a pretty expensive machine, I expect there should be something to do software-wise to get more battery out of this machine. My goal is to bump up the battery life to 6 hours at most (and at best).
The progress so far: I am trying to figure out what are the different causes that make an MBP to consume a lot of battery under Boot Camp. If there is a way to increase the battery life, it may be a nice tutorial for those that have a similar use case. With that being said, I have done the following:
- ThrottleStop: Undervolting the CPU does improve thermals and makes the laptop run a lot more efficient! Beyond whatever typical undervolt settings one can apply to their machine, and when not connected to any battery source, I have disabled Turbo Boost (If I require a lot more raw power I will plug in my machine to any outlet because of course the battery will be drained). One big caveat is to never use Intel's XTU as that can disable any Turbo Boost under Boot Camp and you will require something like ThrottleStop to make your laptop to boost up naturally - not sure how these settings are stored within the firmware, but during trial and error, found out that XTU causes major issues with this under Boot Camp
- Fan control: A more aggressive fan control does help. Macs Fan Control for Windows, or any other user-controlled fan solution is a must to keep things cooled down. This is not specific to battery, but found out that it is very much needed under any circumstance to avoid having a hot potato in your hands.
- Battery saver: Start the "Turn battery saver on automatically if my battery falls below" setting from your profile at 70% to avoid major drainage from your laptop battery early on.
- Latest BootCampDrivers.com: Not sure if this is available to regular Boot Camp drivers, but under "Advanced Power Settings", make sure you have the AMD Powerplay Settings configured for "Maximize Battery Life" under "On Battery"
The problems: And these are the things where I'm stumped, I am assuming that these may be the culprits of why energy is drained faster from the system, but my guess is that to resolve them, I need the help of someone who is intimate with UEFI settings, knowledge of drivers (or something in between!) All of these issues were listed from my system when running "powercfg /energy":
- USB drivers that do not enter Sleep State: I am not sure what this device is for in particular, but since it does not go to sleep it may consume a significant amount of energy. Not sure if it's the Touch Bar (would not be surprised) And I'm not quite sure how to change this setting for a specific device (or even if it would be supported, as I am assuming there is a lot of driver involvement for this to take place).
- Apple USB Composite Device:
- Host controller ID: PCI\VEN_8086&DEV_A12F
- Device ID: USB\VID_05AC&PID_8600
- Apple USB Composite Device:
- Platform Power Management Capabilities:ACPI _PSD Object Failed Validation: As this is the power interface, I am assuming that an MBP is running power configuration settings differently than what Windows expects - Not really sure how to improve these at the moment.
- Platform Power Management Capabilities:PCI Express Active-State Power Management (ASPM) Disabled: Since ASPM is the power facility that is used to sleep and wake up PCI Express devices, I'm assuming there is a similar issue as with ACPI.
And that's about it! Been trying to look online about these particular issues and have gone nowhere with them 🙁 I am assuming that some of these settings would have to be changed through the use of rEFInd. Any pointers would be really appreciated!
Note: I know these have certain limitations, as while there are MBPs with dGPUs that will naturally will drain battery - but bcd.com drivers recently have made my battery life wonders!