I've been explained that this is because those computers might need more power than the AC Charger is able to provide, so the battery is also used as a "backup" for burst loads. This [1] seems to confirm it.
Thanks for the info. I recently discovered this by running folding at home on my 16inch pro overnight, and waking up to my battery being at 5%. I suspect running the CPU full bore over night was too much for the charger to keep up with.
Isn't this bad design? Surely if plugged in, you should be able to use everything on your laptop at 100% utilization (screen, CPU, disks, fans, etc) without having to worry about it.
Otherwise, what's the point of having those things?
I suspect this is due to USB-C providing a maximum power of 100 watts. This was a classic design trade off. “We can support an industry standard and thus allow ubiquitously available chargers to be used with the device, with the trade off being that the chargers can’t keep up when the device is run continuously at full throttle.”
Then it’s a question of how many are impacted and how often, how support for USB-C factors in to the decision to purchase, etc., etc.
It’s a trade-off - they COULD build a laptop which can run everything at 100% 24/7 indefinitely, but it’d be heavier and more expensive, with zero benefits to their target audience of "people who only run at 100% for a few hours per day"
No, He is talking about the laptop not getting enough power while plugged in.
If there was any added weight it would be with the charger, not the laptop so... Incredibly unlikely.
It's way more likely that Apple just didn't design the connector to be able to deliver that amount of power. So they'd have to add a second one or switch connectors/design a new one.
Everything that does not expose to the user what is happening, and ideally give the user control over what can happen and when, is as bad design as clippy was on Microsoft Word.
Only too-clever-for-their-own-good-designers like automagic things. No user does.
Is your car designed to be used with the pedal to the floor at all times?
I don't understand why this would be a design assumption, especially for a portable device.
This isn't even an assumption for running applications on servers, especially the kind that serve up things like web requests. If you have pegged the CPU, your application will already be unstable.
Sure, the server can handle being pegged 24/7 from a power and cooling perspective, but in practical use no sysadmin will allow that to happen for very long.
Speaking of which, can some electrician please explain why Apple chargers (for USA) use ungrounded plugs while every computer I've ever owned uses grounded plugs?
This is the case in many places outside of the US as well, as far as I can tell. The included extension cord (C5?) was grounded at least for my last MacBook years ago, but they provide a non-grounded connector probably because it's less bulky (easier to design as a folding mechanism) and more universal (especially in continental Europe where the two-prong is nearly universal and the third prong is far from that).
It's also not just Apple. Lower wattage Lenovo chargers (including ThinkPad) have two-prong adapters and plugs.
This makes sense. My USB C portable charger also cannot keep up with charging my laptop while I have the screen on full brightness + normal activities.
If you look at how the charging amperage is in current chargers, as compared to those of a few years ago, it's pretty easy to tell that this is the case.
Sure, some of it is due to improved efficiency of the components, but when combined with power drain while on a charger under high loads, it's fairly obvious.
Same here. When I started working from home, I set up an external monitor with an HDMI-to-USB-C adapter. Whenever it's plugged in, my battery goes down about 4% per hour with the AC adapter plugged in.
I've only ever seen my laptop's battery discharge while plugged in via one of those USB-C hubs which allow PD "pass-through". But have yet to find one that passes all the power through.
The adapter claims some of the power for itself and downstream USB devices. I think it has to reserve power statically, so it's always claiming 5W or so.
Are you using the smaller Macbook-vanilla charger or something?
I game on my Macbook Pro + two monitors without discharge unless I accidentally use my girlfriend's OG Macbook charger instead of the Pro's charger that's twice the brick.
And it can definitely handle Civ 6 (2017 and 2019 MBP).
Not sure about the parent, but my friend an I had exactly the same issue, both of us are on 16inch MBP 2020 (Civ 6 on Steam).
Incredibly annoying once your laptop suddenly slows down and dies after 5h of gameplay. How is this even acceptable? Regardless whether it's a $400 or $3k laptop, I'd expect it to work when charging. I'm two apps (photoshop, lightroom) away from switching to Linux.
Probably more to do with FAA regulations than anything else. You can't put more than a 100W batter in a laptop, and the charger is 100W (96W, I think), but modern processors and GPUs need more than that at full speed with all cores, leave along fans and SSDs and screens. My similarly specced desktop runs at 400W, not including the monitor.
So yeah, we seem to have hit a limit with traditional chipsets. Probably why Apple is going full steam on their own ARM SoCs. The iPhones and iPads out now can do some pretty serious work, just imagine what could be achieved by bringing that power to the Mac.
The FAA has no restrictions on chargers, the restriction is on battery capacity which is irrelevant to this problem. They use 100W chargers because that's the highest allowed by the USB-PD spec, but Apple providing power supplies incapable of handling peak load on their laptops is much older than their use of USB-PD. They just seem to not care very much about the heavy sustained load use case.
I believe the frustration is more due to the fact that even though the laptop is plugged in, the battery gets drained and after a while, it will simply shut down.
I have had that issue with 2012 15 inch, 2016 15 inch, 2017 15 inch and heard similar stories from 16inch users.
Reminds me of the early brick-sized mobile phones. Sure you could be wireless, but if you wanted to use it more than few minutes, you had to find yourself a power socket.
I believe some of the MacBook Pros ship with chargers that cannot power them when running at full tilt. (Interestingly, I believe the original iPad Pro did as well.)
Yup. I've got last years Macbook Pro, fully specced, and when I run lots of compilations in Xcode the battery steadily drains. I ran an intense script overnight a month or two ago and when I got back in the morning my battery was down to just a few percent. Thankfully the script finished just after that so I got incredibly lucky that it didn't run out all the way and lose all the progress.
Funnily, the base model is unlikely to have this problem, which makes it a better laptop (at least in this case) for cheaper. Your script won't stop and lose progress.
That was the case for my rMBP 2012. Though it was only when running a game and battery discharged very slowly, so was not really an issue, at least for me.
> Are you using the smaller Macbook-vanilla charger or something?
Yes, that's exactly what the situation was. I was just trying to confirm the phenomenon of "battery can discharge if the AC adapter is temporarily insufficient"- but the core problem was my fault for sure.
oh, actually it was my fault. I have an air charger and a pro charger, and it turns out they're not interchangeable. The pro charger is, like, 30% bigger, and the laptop battery will not discharge while I'm using that one.
My laptop is one of the older magsafe ones, so the people talking about USB-C might be a YMMV kind of thing.
Strangely enough, they did exactly as suggested when batteries started wearing out on iPhones (unable to reliably provide the voltage at full drain for peak performance) and you're the exact kind of person who jumped on them for planned obsolescence.
The PowerBook 145b was my first Mac. Wonderful little machine. 4 MB RAM, 80 MB hard disk. I ran a web browser on it, MacWeb, and could surf the web as it was back then perfectly fine. Not today, I suspect.
This probably goes hand in hand with the unremovable batteries. Back when they had removable batteries you could run it on AC with no battery installed and it would work fine.
No, thats purely to prevent repair. Its perfectly possible to have a removable battery and to just not boot when one is not inserted. Thats how phones used to work ~2013
A removable battery requires its own protective shell, which costs weight and thickness. When it's not user serviceable, it can just be a bag of acid resting on the main board, piggybacking on the device's own case for the required protection.
The protective shell can be only the bottom side which replaces the bottom of the case. The internal laptop batteries are quite safe to handle if you don't use anything sharp on them. We let people handle phone batteries for ages and they weren't nearly as protected as those old laptop battery tubes.
They were certainly more protected than the almost naked ones I see right now which I can singlehandedly bend (but won't given the fire hazard). And not LiPol batteries too, which are super nasty in that regard: the more energy-dense the battery is, the more of a hazard.
Non-removable just means it's soldered down. Open a phone and you will see that the batteries certainly have just the kind of plastic shell that they always had.
most phones and tablets i've worked on recently certainly do not have any plastic shell on non-removable batteries; unless you consider shrink tubing a shell.
They are usually constructed of layers of battery material, wrapped in kapton tape or an equivalent, with the entire package shrink-tubed and a pigtail coming out the side for the device interface.
One could easily crush the unit by hand, the construction offers little to no protection from physical forces.
I’m not saying one is a requirement for the other, just that you don’t have to worry about the battery-removed state when it doesn’t exist.
From the tear downs I’ve seen, it seems like the primary motivation for the non-removable battery is so they can cram it into every spare piece of space.
I guess there are also multiple states of removable. 2012 macbooks had the battery in multiple packs in odd spaces like the new ones but they had a screw in bracket holding them in place which made it trivial to remove and put a new one in. The new ones have it glued down so heavily that the battery replacement process is "Take the screen off, put it on a new bottom case, throw out the old bottom half"
Having opened both my 2008 Macbook (with removable battery) and my current 2015 Macbook Pro (with non-removable battery), it's easy to see why: the 2015's battery is actually 4 different batteries of varying sizes & shapes. It's taking most of the space inside the computer that isn't taken by the motherboard (about half, actually).
Making stuff removable is a lot more work; you have to build a way to hold the thing while it's on, you have to put in connectors, etc. With non-removable batteries they can just glue them on & solder the wires.
Not really saying it's a good thing, but I understand the decision.
Though in practice, the magsafe connector wasn't cat- or human proof meaning when one of those gets as much as near the cable it's byebye unsaved work and in worst case byebye boot because of a messed up system. I ended up taping the connector to the laptop to avoid that. As to why I'd run without a battery: it was swollen.
From what I've seen, none of the high end Mac book pros have a good enough charger to provide enough power for a mixed CPU/GPU workload. And with the switch to USB-C and it's 100W power limit they can't even fix it now.
the case where the laptop draws more power than the AC adapter can provide is probably some sort of brief turbo state for the cpu and/or gpu. it can't maintain this for long without overheating.
[1] https://web.archive.org/web/20081225111200/http://support.ap...