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Comment by knodi123 | Hacker News Reader

ha, well I've noticed my battery discharges if I play Civ 6, even when plugged in. so that confirms it too.

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.

Are you sending your power via a USB C adapter too?

If you use one of these[1] then your laptop will charge more slowly than if you just plugged in the power directly.

[1] https://www.apple.com/shop/product/MUF82AM/A/usb-c-digital-a...

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.

My charger is an Apple product; it was the lowest-price charger they had available ($73 after tax). Two components:

* charging block

* male USB A to male USB C cable

EDIT: I just clicked your link; no I'm not using that. The cable is plugged into the charging block on one end and the laptop on the other end.

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).

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.

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.

I would understand if $400 laptop had low power charger to cut price. But on $3k "pro" laptop it is just middle finger to customer.

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.

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 still find this a bit peculiar, I haven't experienced that in any of my previous machines, mac or not.

Normally, I'd call customer support and assume it's an issue with my device specifically. HN saved me a bunch of annoying phone calls.

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.

ARM seems like the way to go. I recommend comparing the energy usage of Macintosh II and Macbook Air. It's quite impressive (minutes vs hours).

I solved my few Windows dependencies with https://wiki.archlinux.org/index.php/PCI_passthrough_via_OVM... and a secondary GPU. (Might not fit your current setup but it was a game changer for me and my productivity so I can highly suggest it.)

mhm, tempting

> 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.

this kind of behavior would warrant a return from me.

do you consider that to be a faulty behavior, or just par-for-the-course of heavy workloads on mobile platforms?

i'd hate for that to be the new norm, I use the hell out of my mobile computers, I don't need them draining before I even unplug.

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.

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