Can I trick my MacBook into thinking it has a battery connected?

@arbaman - Well said!

@danj Thanks, also for putting all the effort to make it look nice!

@arbaman - You did the work!

I'm jealous! You still have a working 2011 17" MacBook Pro! Both of mine died ;-{ I was hard on them.

@danj I've been surely lucky with it. I enjoyed many hours gameplay with it, it has been my favorite for schematics and it became a temporary decent mini-Tv when the telly got fried.

Only thing I remember I had to fix was a nasty mosfet that died out of a sudden and triggered bad temperature reading with usual kernel task and fans issues. That's all, graphic card still kicking.

Sorry for yours, they're nice Macs to keep in memory of the good old days.

Well… it’s not so straight forward! So you buy a car do you not replace the worn oil and filters after so many miles? Let’s say you don’t and you aim to run it into the ground Vs your twin who drive the exact same car and gives it all the TLC it needs, clearly your car will head to the junk yard a lot sooner that your brother!

On the most part that also holds true here, it’s just the battery needs replacing either because of age or cycle count. The system self preservation (SMC) logic is designed to protect it’s self from over heating and when a battery needs replacement. That’s not obsolescence, that’s to protect you from a lithium fire!

I wish it was so simple! Given the amount of effort trying to redesign Apples battery circuitry to support different batts it’s not really practical.

@danj According to this link https://www.edn.com/teardown-debugging-a... it is three ordinary 4.2V Li-Ion cells put in series and running at lower voltages for durability. But I did not have the time to track down any seller for those, I assume about 8000mAh for each cell. I assume as as long one has the controller salvaged from a dead battery it is not much of a problem to built your own. And at one point, there is no other way when battery spares are not available any more. Just to put this effort into perspective: My 2011 Macbook upgraded with 2x4TB SSD is fast enough to edit 2k Video, for higher resolutions I use it for offline editing. With the onboard GPU of the Intel chip as the external GPU died its famous death even twice, maybe folks remember. So this Macbook is crippled and still useable.I guess if not any crucial part dies, I will still use it in 2034. So many batteries later counted from now on...

@herbertmueller - If you use like for like using the original logic board and make sure the sensors are properly mounted then I can see this as a workable solution.

But you really can’t use different sized batteries (different mAh) and the chemistry needs to be basically the same as the charging curve within the logic is designed for the batteries Apple used.

To be clear here, add we are doing is reconstituting the battery with fresh cells not faking the computers SMC logic.

@kevinc2019 So basically what you're saying is that Apple engineers have been so dumb to fit on a 1800/2200 $ laptop a subpar battery that cannot take full advantage of the processor unless it's connected to both mains and battery simultaneously ?

No. I wouldn't say that computer engineers are dumb. I'm only saying that modern laptops provide the best performance on mains, not battery.

@kevinc2019 - Well... Thats partly true! Older Windows Intel systems are known for that!

Mac's on the other-hand have a more balanced power/performance framework. Thats not to say a Mac won't throttle down, it just does it at heavy load (high temp) unlike many Windows systems. To add to it, it makes no difference powered by the mains or via battery alone its the same.

Apple desire for thin was a big blunder with the 2016 onward Intel systems as the CPU's needed more aggressive cooling (Intel forgot to tell the hardware folks the truth), the only failing in these thin systems is the power runs out too quickly for the tasks many people were using them for.

Part of the problem is it takes about three years to spec and design a system, but the needed performance bar (what peoples Apps needed) moved faster than Apple (as well as the others) realized! Apple's M1 & now M2 SoC's shows us clearly Intel had failed in creating a cooler running chip that Apple begged them to produce.

Forget all of the integration Apple achieved within the M1 & 2 SoCs, If you pull out all of the extras it would be even running cooler and need even less power!

So why didn't Intel produce the better chip? And no, as we also saw from Apple with Rosetta2 running Intel code on an ARM chip is possible and not get heavily bogged down in the conversion.

If Intel had really tried Apple wouldn't have made the jump to their own silicon. And they can only blame them selves and now are playing catch up!

I'm very impressed with Apples SoC effort so far, sure its still needs better L1 & L2 memory caching and fetching which appears to be holding back multi-threading a bit and the clocking needs to be better for single thread performance. But given what they have achieved its very good!

And getting to your point the system needs to be powered by the mains to get the performance (Windows/Intel systems). Apples SoC's have no problems or performance limits that stop it unlike the current Intel chips in similar sized systems.

@danj My 17" 2009 never throttled w/o the battery (couldn't leave it in due to cell expansion). I will forever miss the true AG screen those had in the unit if they were properly configured, which is why I ran mine to the ground even with the battery removed. While I am sad, I can get a high end P3 IPS display with a true matte panel.

But man even w/o the true AG screen, those M1 Max 16" machines eat the Intels for lunch. I didn't think my 2014 standby would be murdered within 2 generations of M1.

@nick - The Core2Duo generation didn't face the issue unlike the i series (i5, i7 & i9 CPU's)

The issue the OP was dealing with is how the System Management Controller (SMC) works in managing the thermals and cooling. Its designed to go into CPU Safe Mode when it looses access to its thermal and voltage sensors, pushing the Fan's RPMs and lowering the CPU's clocking to reduce its heat.

@kevinc2019 injected some incomplete info that I was correcting and putting things into perspective.