M1 Macbook pro battery life halves whenever a display or USB-C hub is plugged in

It's not a fault in anything.

Your Mac was never intended to support external displays and other devices without the power adapter. it is not a device like an iPhone -- You Mac was never intended to run all day without additional power, unless you are using it like a student taking notes in class, without additional peripherals attached.

If you attach a display or Hub, attach the power adapter as well.

Hi jakemdu,

It seems you're having some trouble with your connected monitor causing a battery drain and we can help.

What sort of resolution is the external monitor running? Have you tried changing any display settings?

Try the steps to change your display resolution and see if that helps:

Get help with video issues on external displays connected to your Mac

Try and review the Activity Monitor to see what that says is having an energy impact:

View energy consumption in Activity Monitor on Mac

Let us know what happens.

Thanks for using the Apple Support Communities.

That computer is a battery-CAPABLE device. It is not optimized as a battery-operated device.

Your computer performs best when connected to AC power. It can use the full output of the Power Adapter AND when doing especially challenging work will also freely "borrow" power from the battery. In some cases, the charged state may even decline during stressful work.

When used only on battery, your computer has no extra cushion of power, and will perform more slowly. However, for ordinary non-stressful tasks this may not be objectionable (possibly not even noticeable.)

In general, you should ALWAYS connect AC power when it is possible to do so, and only run on batteries (which will be somewhat slower) when no AC sources are at hand. There are three micro-controllers cooperating on battery and charging issues, and your Mac will NEVER over-charge.

jakemdu wrote:

M1 MBP - when connecting what seems to be anything to my Mac - my external monitor via USB-C to HDMI cable, or my USB-C hub (not self-powered), my battery life almost halves.

Just to be clear, it still is good battery life! Just works out more like 10 hours rather than the claimed 20 hours, unless nothing is plugged in, in which case the 20 hours is achieved!

I would recommend peripherals with their own power supply.

Keep plugged into the mains, unless you need portability—which in most cases would eliminate external monitior and a USBC hub.

Under a heavy load even plugged in, the computer will still pull from the battery for extra power if needed.

If you wish to use your device like student taking notes in class, with no peripherals attached, its battery can last all day.

The moment you connect high speed peripherals or displays, power draw goes up sharply, requiring you to plug in the computer as well.

Since almost without exception these peripheral devices also require AC power, you should take the hint from your peripherals that battery-power will not suffice, and plug in the computer as well.

If you want to use desktop-calibre peripherals, those are supported. But they use a lot of power.

As I said above,

"That computer is a battery-CAPABLE device. It is not optimized as a battery-operated device."

Yes, I have compared, MBA M1 with USB-C Hub plugged in it drain fast battery so make sure to use with chager plugged in too. I hope there is update to solve this

I see the exact same issue with my MBA M1, the battery drain is extremely fast with an external monitor (3.5 hours to go to 0% when doing basic mail/word/internet with a usb-c and display plugged in). Much much faster than what I ever saw with my previous 8-years old intel-based macbook air.

It's clear that anything connected to the MBA when not plugged in will impact the battery, but the extent of this impact on my new MBA M1 is just crazy... Pretty disappointing.

The M1 is extremely power-efficient. But it take POWER to run stuff at the high speeds associated with Thunderbolt and high-speed USB-C.

Hi Grant

Of course peripherals will draw power, nobody questions this really.

The point here is that the same peripherals drain the new M1 laptops battery much much faster than than they do when used with intel-based mac laptops. So it really feels that that, from this point of view, M1 laptops underperform quite dramatically compared to previous intel-based model and this is disappointing.

Dude, I have the same issue here.

When I plug my hub it decreases the battery's remaining time by more than 60% of its normal time.

I wonder if regular dongles and Apple media cable also do this!

Yes, the extra power to operate the additional devices has to come from somewhere. There is no magic electricity tree.

Hi,

I also noticed this when I have an external thunderbolt SanDisk SSD. The battery lasts for only about 8h. It should not draw that much power just having it plugged in?

Well not so efficient on this aspect actually since intel-based mac need less power to make the same peripheral work.