Why did my 2012 MBP perform much worse without a battery?

[Grandesigns]

I recently spent a week or so using my Mid-2012 i7 MBP without a battery installed, and found that its overall performance during that span was much slower than I am accustomed to. My working theory is that the system has power need "spikes" that are more than the power adaptor can handle without the battery to act as a buffer, so the MBP was throttling itself to stay within the available power envelope.

Does anyone know if that's right? Any other theories?

 

[Honza1]

This is known fact. To prevent brownouts, Mac notebooks without battery will slow down to reduce power consumption. Battery is used under normal conditions to supplement power source as needed.

 

[Grandesigns]

Great to know, thanks!

 

[Mohanak]

why not the case with iMac?

apple doesn't want a MacBook to get much life.
mid-14 15" macbook: battery is 95-watt but the power supply unit is 85-watt.
2019 16" MacBook pro: battery is 100-watt output. but the PSU is 96-watt.

i don't think post-2010 models could run without battery. in cases like disconnecting swollen battery for safety.

they don't WANT macbook to run good on power.

forget about sudden cable disconnect. it's not a problem. this is a user issue.
forget about power assumption excuses. it's happening with battery already.

older mid-2000s macs and PCs run well on AC-DC power adapter cables
but not for the recent models.

 

[matram]

apple doesn't want a MacBook to get much life.
mid-14 15" macbook: battery is 95-watt but the power supply unit is 85-watt.
2019 16" MacBook pro: battery is 100-watt output. but the PSU is 96-watt.

The 2019 battery is 100 WattHour, this is a measurement of Energy, not Power.

 

[Mohanak]

found this:

Running a macbook without battery ... let's go:

Please Note - Aug/2024: This is probably now completely outdated and I am not maintaining any part of it, use at your own risk. A pandemi...

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