MacBook Pro 2011 15" Battery going down while playing WoW

I've the same problem (macbook pro 15" 2,3 2011) and i add that if the battery go to 0% the computer doesn't go in hibernation but shut down resetting also clock info, spotlight index, ecc... (excuse me for my english, i'm italian)

As far as 85W being enough for WoW (or 60-65W if you use an older adapter), one way to get a handle on power drain is to run on battery and see what the battery current and voltage are (from system profiler under power) or roughly with the time remaining indicator. Playing WoW at pretty high settings and no framerate cap (getting about 60fps) and a full battery I see just under 4000mA at 12V, which is 48W. Capping to 30fps gets me down to closer to 3000mA (36W). You can also estimate that since the MBP 15" has a 77Wh battery that if you're getting runtimes in the neighborhood of 2 hours, the power drain is around half that, or less than 40W.

The only way you get even close to the power limit of even a 60W adapter is if you're powering external peripherals, running CPU intensive background tasks, or trying to charge the battery while playing WoW.

I'm not sure what the max charge power Apple uses is, but even at the start it's probably no more than 40W. So, with an 85W adapter you should be able to charge at full speed and play WoW.

At least as far as the adapter is concerned. Whether the logic board can process 85W input continuously is another matter.

If your battery is being drained while playing WoW, and it started at full charge, then I'd say you have a hardware problem even if you were using a 60W adapter at the time.

It's impossible that all of us has a hardware problem...or not?

Could be. What sort of time estimate or current draw do you see playing WoW on battery, with a fully charged battery? Is it much more than 4000mA?

If not, and the AC adapter isn't faulty (i.e. really only delivering <40W) , then maybe reset the SMC? (shift-control-opt + power button, release simultaneously)

I'm rebumping this issue.

I have found the same problem on the 15" late 2011 MBP and this thread still applies to current 15" units.

Anyone else have this issue today?

Yes, I just bought a 2.4GHZ i7 MBP 17" over the weekend, swapped out the 4G RAM for Crucial 16G and my battery is discharging when the 85w power adapter is plugged in. I am running Lion (10.7.3), Apple Mail, Chrome, and most notably Parallels running Windows 7 for a day trader stock application. I've given Parallels/Windows 4G of DRAM and permission to use as much processing power as it needs (chose performance over power).

The fans really kick up after the market opens, and after a couple of hours I noticed that the battery icon says "not charging". Pulling the power adapter off for a few seconds shows the battery charge in the 70%'s one day and 80%'s today. The odd thing is that using activity monitor the four processors are showing only 30-40% cycle usage. The secondary cores are all about 10% usage. I used both the Thunderbolt display's powere and a separate 85w wall bug with similar results.

I'm OK with the machine not re-charging the battery under maximum plugged in power load - but it should not drain the battery when plugged in and it certainly should not do that without telling me. And at 40% processor load?

I took the machine to the Genius Bar last night and it passed all of the tests, including battery load and source. I'll watch it more carefully with a battery charge utility and system process monitoring utility tomorrow before decisign what the next course of action is.

The more powerful MBPs have gotten, the more power they consume, yet they're still shipped with the same 85W power supply that came with dual-core, no-hyperthreading, 1.83GHz Core Duo MBPs in January 2006. When the AC adapter can't supply the demand, the battery is called on to make up the difference. That can't happen without draining the battery. You don't have to like it, but there it is, and it isn't going to change until processors get more efficient and/or AC adapters deliver more power (and MBPs are designed to dissipate more heat effectively).

"...and it certainly should not do that without telling me."

Ah, but it is telling you. That's what "Not charging" means. Every battery that's not being charged is draining — only the speed varies.

At 40% CPU usage on the primary cores and 10% on the secondary cores we're drawing on the battery? That still sounds a bit off to me.

And I disagree with "Every battery that's not being charged is draining" - for years with the Apple Airline adapter the battery will not charge, but it will not drain either. Only when airline power is removed does the battery take over. I use a standalone battery pack to travel acorss country with my other prior MBP and can guarantee that I can have a 100% battery when I only power externally. If the battery is being used then the user needs to know about it. And I acknowledge that there is a defacto leakage of charge off any rechargable battery that is outside the scope of this conversation.

It doesn't matter to me what you disagree with. Your MBP is telling you what the practical facts are, and you'll have to live with them if you want to use it. If not, return it and buy something else that you like better. It's working as designed.

eww, are you always so unhelpful?

I realize exactly what my MBP is doing, thank you - in fact my electical engineering training gives me great insight into the issues and the semiconductor & power control technologies that are making it happen.

I'm still wondering if others with 40% cpu loads are seeing this. If this is how the new MBP is designed I can only imagine what 75% + rendering loads on 8 CPU's might quickly do to the battery.

With all due respect, eww, since after two posts you did not report a personal experience with this and did not respond to the discrepancy of a 40% CPU load and the abttery still discharging, I'd prefer to hear from others actually dealing with this situation. Go earn bonus point 51,806 on someone else's post.

You couldn't award any points to me in this thread if you wanted to, so rest assured that was no part of my motivation in responding to your post.

Dean Suhr wrote:

eww, are you always so unhelpful?

I realize exactly what my MBP is doing, thank you - in fact my electical engineering training gives me great insight into the issues and the semiconductor & power control technologies that are making it happen.

I'm still wondering if others with 40% cpu loads are seeing this. If this is how the new MBP is designed I can only imagine what 75% + rendering loads on 8 CPU's might quickly do to the battery...

While there's a lot of emphasis on CPU loads, I haven't seen any mention of the GPU that's in the new MacBook Pro's. A chart here: http://en.wikipedia.org/wiki/Northern_Islands_%28GPU_family%29 suggests to my untrained eye that the GPU alone could be drawing 80 or more watts all by itself when running full bore. That should be more of an issue with gamers, but I've noticed the temperature rising quite a bit on my Mac Pro, especially PCIe slot 1 which holds the 5870, when running Windows XPMode in Win 7 Pro in VMware Fusion with 12GB of RAM assigned, suggesting a lot of power is being drawn during virtualization. Fortunately, both power and cooling are not an issue on the Mac Pro but they surely would be on a MacBook Pro, and neither power nor cooling may be up to that job, including the power adapter.

I'd appreciate correction and explanation if I've misunderstood Wikipedia's chart and/or it's application to the issue at hand.

You're quite right. In all or most of the cases reported here involving MBPs draining their batteries with their AC adapters connected, the discrete GPU was in use at the time. The paucity or absence of posts reporting such a battery drain when the integrated graphics are in use instead suggests that the discrete GPU is a huge energy consumer whenever it's active — as it is whenever Windows is running, whether natively or in virtualization.

A couple corrections:

First, the link for Radion GPUs provided above are the desktop parts. The mobile versions are here, and their maximum power is typically slightly less than 1/2 that of the desktop part. For the 6750M/6770M, it's not listed, but you can expect somewhere below 40W TDP

Second, TDP is not necessarily the maximum power draw of the part. The actual max power may be a bit higher or lower than the TDP.

Third, the TDP of the quad-core i7 in the MPB is 45W. Practical exprience say that with Intel CPUs, you can count on the actual power draw not exceding the TDP. At 40% CPU utilization, the CPU is probably drawing no more than 20W, and may be much lower depending upon how many cores are active.

So, even with 35W-40W for a maxed out GPU + 20W CPU + 5W-10W for the rest of the system, you're not near 85W draw.

A good tool for determining how much power you're actually using is iStatMenus. It's not free, but it does have a 14 day free trial.

It does sound like there is a problem, but whether it's HW, Firmware, or software is unknown. If I were betting, I would put money on it being the system/power management firmware. I would suggest opening a problem report with Apple.

Try looking at the actual power draw in System Profiler. Under Hardware->Power there should be some lines like:

Battery Installed: Yes

Amperage (mA): 471

Voltage (mV): 12551

If it's charging then Amperage is positive. 85W would be over 7000mA at 12V, and the bottom of the case would melt through the desk.