XPS 15 9575, modern standby, backpack, fans

Thank you for your message. Does the battery drain too fast when you put the system to sleep mode or while in the backpack?

What is the BIOS version installed?

The system may be on a modern standby & if there is any process running in the background it could be using the CPU & draining the battery as well.

For my reference, please click on the message tab next to your avatar– click “New Message” & search for my Dell username (Dell-Sreejith R) & send a private message with the service tag, registered name & email address.

What is a Dell Service Tag and how do I locate it?

@JOceanUnfortunately, the problem comes when the laptop is in a closed environment. The computer *should* be smart enough to realize that the fans are having the opposite effect of what they're intended to do. The fans are there to protect the PC, but in this case, they are actively destroying it.

I hate to admit it, but I've been using a MacBook for years. Every time I shut its lid, the fans immediately stop, no matter how hot the laptop is. This is good design, because if I'm closing the lid, there is a ~90% chance that within one minute, the laptop will be zipped up in a bag.

Hi Sreejith,

Thanks for the reply. It only happens sometimes, and when it does, yes, the battery drains while it's in the backpack. Sometimes it successfully goes to sleep, and the battery doesn't drain. I've had it in the backpack for over a day before with no problem, and other times in just a few hours the laptop is scorching hot, fans whirring at full speed, with over 50% drained battery.

I just updated the BIOS right after I got it (about a week ago) with the latest one listed on the Dell support site.

I've set systemd to not allow interrupts to stop the sleep mode when the lid is closed, so I don't think anything could be stopping it from trying to sleep.

@SreejithRPer your private message, which I've copied below:

Firstly check which sleep, S3 or Modern Sleep (connected standby). May depend on the BIOS version - in 9570 Dell killed S3 with a certain irreversible BIOS update. 

Unfortunately, XPS are known to sometimes wake in sleep running hot in backpacks both in S3 and MS. 

Wake from S3 sleep may be due to system configuration, due to a wake-armed device or a wake-timer, for instance for windows update. Check the powercfg command in the admin cmd window. Waking is with XPS also known to occur due to a faulty automatic transition from sleep to hibernate after a pre-set time like 2h, which may be disabled. 

Modern Sleep is recently pushed by Microsoft, and Dell don't seem like supporting two forms of sleep while not really being able to debug any. The "advantage" of MS/CS is that the laptop doesn't really sleep, checks for email/messages all the time. So it also wakes up faster. The problem is the same, that it doesn't really sleep... Tends not even to go to sleep if working on something while being sent to sleep, tends to drain the battery twice as fast as S3 etc. One relies a lot on the nonexistent responsibility of software developers to properly adhere to guidelines (which they have probably never heard of). You may try entering Airplane mode before Sleep, but I hear some programs get really mad if you want to deprive them of internet and keep polling, draining the battery even faster. For many, such sleep is of no use, it isn't fun when useful features are getting replaced by inferior ones in supposedly classy laptops. 

You can try using Hibernate instead (for me, hibernate is less reliable unfortunately, often cold boot instead of waking up). 

I just tried it again, and it seems like it will prevent sleep mode if I pick it up right after closing the lid, but *only* if the fans are running/the OS is pretty busy. If it's sitting there doing nothing, fans silent, I can shut the lid and shake it around, and it will still sleep. (And very quickly, too. Basically as soon as I shut the lid, the audio stops.) If the fans are going though, picking it up/jostling it right after closing the lid will consistently prevent it from sleeping (audio keeps playing, fans keep running).

@SreejithR  I've found that if I close the lid and leave the Dell sitting in place for about a minute before picking it up, it will go to sleep and I can put it in the backpack. If I pick it up directly after closing the lid though, it will not go to sleep and start the fans, and I have to open it up and close it again for it to go to sleep. Does this laptop have a gyro? If so, maybe that is sending an interrupt to the CPU and keeping it from sleeping.

@samos1111  I've looked through all the BIOS settings and tried flipping a lot of them, to no avail. There's no setting for what kind of sleep mode to use. But, sometimes it goes to sleep correctly, and hardly drains the battery at all over many hours, so I think it really is going into proper sleep mode. My Surface Book will *always* drain the battery by about 30-50% per day while in sleep mode, so it is definitely using the new and improved, super awesome, battery killing, connected standby instead of just going to sleep. Yay, Microsoft.

On the Dell, I don't use Windows. I use Manjaro Linux, with systemd, so it doesn't even support "Modern Sleep" anyway. It does have a "hybrid sleep" option, which copies all the RAM to disk, and puts the computer to sleep. Basically a hibernate+sleep. But losing what's in RAM isn't my concern. My concern is that the firmware, while trying to protect the PC, is inadvertently damaging it by running the fans full blast in a backpack.

If using Linux better look for support in the Linux community and perhaps at Dell reddit. 

So this must be S3 sleep and its issues... 

I'm not familiar with Linux... In Windows (9550) I set "lid close" to "no action" and I always put it to sleep via the Start/Power menu, so that I can see if it has actually gone to sleep. I guess you can do this too? Yes less convenient but I've had this bug where the laptop was waking up by itself a couple of seconds after going to sleep. It is reliable now but I'm still paranoid. The bug was initially triggered by the malfunctioning "Hibernate After" feature - the laptop woke up after a preset time of sleep to switchover to hibernate, but the switchover failed and instead the laptop woke to an abnormal state in which it was mostly functional but some things like sleep didn't work anymore.  

@SreejithR  Would you be able to file a bug report for this? It's pretty annoying to have to wait before picking up my laptop when I'm in a hurry.

Hi buddy,

I have exactly the same problem, any chance you found a solution?

Not really. Just hold it up to your ear after you close it to see if it stays on. Dell doesn't seem interested in supporting their hardware.

After many years (20+) of being a Dell customer, and recently buying many new XPS's for my company, I have finally had enough. The whole point of sleep is that I can treat my laptop as if it is temporarily turned off. I can safely put it into my bag and take it home. To open my bag an hour later with fans on full blast, battery at 50%, and CPU throttled down into safe mode (which requires a disassembly and CPU re-paste to disconnect the button battery and reset the BIOS), is absolutely unacceptable for a $3000 machine.

I'm done. Goodbye.