Maybe run another short test. Are you using your home WiFi for updates? Is Bluetooth enabled also?
If so disable Bluetooth and check the Playstore performance again.
Just recently I had Bluetooth enabled and my Fritzbox had auto-switched to another WiFi channel which interfered with Bluetooth causing a very poor performance while updating.
I never have Bluetooth enabled, so that can’t be it. Also, upon closer inspection it’s very visibly the unpacking and installing that is energy draining.
Could it be that I have an energy-draining SD card somehow?
I have not heard of such an effect yet.
But I once had a Kingston sd card which showed a permanent performance loss after some time. I could not figure out for what reason. Re-formating and even re-partitioning did not help. So its performance now is noticeable lower than it was initially.
But since you have the sd card in focus maybe try installations without it on internal memory to see if there is any difference.
Of course this is easier if used as external memory not as internal. Maybe it has defective sectors.
I’ve a relatively new Fairphone 2, which I’ve equipped with Fairphone Open, Xprivacy and AFWall+ (these are the relevant apps, I think).
The battery really drains fast and the phone is getting hot for no reason – I even cannot carry it in my Jeans pocket any more (Not because it is too hot for my skin, but too warm to be comfortable)!
Yesterday, I was browsing this forum, and it sucked up the entire battery in about an hour.
This is a screenshot I took a few minutes ago:
95% “Sonstiges”!!! I’ve read something about this yesterday, but unfortunately I got so frustrated that I cannot remember which thread I’ve already read and which I didn’t. 
I’ve tried “another monitor”, and it shows the CPU being used >60%.
Is there any kind of guide one can follow to get rid of this seemingly common problem?
I really feel for you. WLan can really suck on the battery; yet your experience is not normal.
Your first stop for advice should be the batteryguide.
Maybe you got some app running, that is draining the battery? The regula Facebook app is renown for all kinds of bad effects. Or maybe your phone is infested by a malware, that is mining crypto currency in the background?
The guide should really help you, unless you got a broken battery of course.
Well, that should be visible, as the ones you read are listed in a light grey script in the “latest threads” list, while the unread/new ones are in black.
Today I had it in flight mode, it stayed hot and kept draining the battery.
The battery isn’t bloated, I’ve already tried the battery reset (twice), and I’ve tried it without SIM and SD card. Better battery stats is installed, but I do not know how to read what it is telling me!?
Pfuideifi, I do not have any Facebook at my device! 
But indeed I suspect that maybe XPrivacy/AFWall+ is blocking anything that is running wild because of that. But how could I determine that? The battery graph keeps saying, it was no specific app, and the CPU monitor doesn’t see anything using that much CPU.
I do not think so. The phone is very newly installed, i am blocking scripts in my Fennec (NoScript) and that kind of computer scientist that thinks octuply before installing anything.
Unfortunately I was browsing the forum with my phone, thus in a private tab without logging in. Sigh.
That really makes me suspect an app as cause for the problem.
I share your feelings. In fact, no Facebook and the like at all,
When my phone turned hot (has not done so since long now), I turned it off and started it anew. Sometimes up to three times. Then the behaviour was always back to normal.
I suspected the alarm clock, as I had programmed lots of alarms, that I activated to requirements and when I rebooted the phone, once in a while lots of “missed” alarms miraculously appeared at startup. Of course I no longer have that many alarms preprogrammed.
So I guess even system-apps can cause trouble, though I have no proof yet.
Bad luck. Haven’t thought of that. 
Now have a look at that! 
2% of the time, the screen is on, 98 % of the time, it is off, but the phone is still active. This makes me think “wakelock!” instantly, even though I’ve learnt that term only yesterday. 
The output of Wakelock Detector makes me think that QKSMS might be the culprit:
As already mentioned in the thread QKSMS and incoming MMS, QKSMS is not able to receive MMS on my device. Perhaps it tries something and fails permanently?
Sounds plausible to me.
Maybe you could try to deactivate MMS for QKSMS? Though I have no idea if that’s possible.
In the newer release it doesn’t occur any more, but there, MMS do not work any more as well. 
Sighhhhhh…
Well, as I read in the github thread link in the other thread here, it’s still a beta version.
There’s some hope, that the final version will offer a working MMS function…
It’s a long shot, but my battery reacted very badly to K9 mail. Many google-free people use that, maybe you do too?
… yes … Is it producing wakelocks, or what is it doing?
You can influence what it is doing e.g. by checking your account settings for how often K-9 checks for new emails.
I set checking for new emails to a 1 hour interval, and I have no problem with K-9’s battery behaviour.
Or it could be something else entirely .
I had similar battery issues, recalibrating the proximity sensor as suggested here: Screen stops working during phone calls since new update fixed the problem for me.
Okay, I just set it to that.
Thank you, will try that!
I’ve similar problems just lately, without new apps installed etc. Phone gets hot, sucks battery. I thought it’s rather the mobile data than the Wifi (or malware?? How to find out? Suggestions?) Battery could be down from 100% to 1% as fast as in 20min. Funnily, when I set it in flight mode when at 1% and let it lie around, more often than not it’s back to 40 or 60% after a couple of hours without charging. So I believe there’s something wrong with the battery gauge, too, perhaps disturbed by the heat?
If the phone gets hot some apps are running amok. It might be interesting to get a logcat. Don’t let you confuse by wakelocks. They are ok, and only a sign of something running astray.
You might also want to install an app like osmonitor, which shows you the running apps and their cpu usage. Also, you’re using bbs, as i saw. Try to get an idle dump for as long as possible, then click on share and just save. This gives you a raw dump where one can see the most…
K9 is normally very good with battery (I’m using it for years now), but if it tries to send mail or scan the inbox, and at that moment your connection goes down (temporarily), it might spin for quite some time and eat battery. And then, the messaging app obviously did that also
I use Watchdog Task Manager Lite to identify apps running amok when the problem isn’t related to wakelocks.
My FP2 battery was 2.5 years older. I had to charge it often, usually just at night (with 5% left) but in critical days, two times. So I ordered a new battery, installed it, charged it and this happened on the first run:
(The drop at the end is me surfing this forum at 4 concurrent tabs speed)
1 day 18 hours (!) under Lineage OS 14.1, 
Also note that I completely disabled extreme battery saving mode (the thing that tints your bars orange), so real battery should be even better.
If your battery is old, consider getting a new one and keep your Fairphone 2 for longer! 
