@amoun
It is indeed the same on all ports.
At the moment I don’t have another charging options. I usually just connect my phone to the PC when I go to sleep.
But as you said, probably best option is just to buy a charger.
@AnotherElk
I did already try both options that but it didn’t solve the issue.
Thank you guys for your help. Really appreciate it.
What happens if you plug the phone while computer on, and then switch the computer off?
Does it charge while the phone off? (I mean really charge, if you let some time and then check the battery percentage)
I tried that. Same.
I waited for more than an hour but the battery percentage never changed.
I have a feeling that while PC is off the phone does charge but extremely slowly that it balances out with consumption. That’s why battery percentage never changes. I’m gonna make another test tonight.
I didn’t try to charge while both the PC and the phone are off.
Hi
Old USB ports would at least give .5A, and form what I can tell if you can chareg other phones it can do that. As the USB gives out 5V and the battery requires 4.4V it should take twice as long as the battery Ah to charge. I.e. with a 3000mAh (3Ah) battery in the fairphone it should that just over 6 hours to charge (given efficiency losses).
You can of course put the phone in aeroplane mode to ensure there are no radio drain, but it should charge.
Just to mention, there are tons of topics about charging slowly, I don’t know if you already had a look: Search results for 'slow charge' - Fairphone Community Forum
Most of them won’t be related, but if you can find something interesting…
Yes here’s my lovely take on that 
Hello guys.
I connected my phone yesterday to my PC and went to sleep. The PC was turned off of course.
The phone did charge but extremely slowly. After 7-8 hours it charged 7% only. Note that WiFi, mobile data, and Bluetooth were all turned off.
When PC is turned on it charges slowly but not like this.
You mean it’s better when switched on?
Are you sure that feature of your PC is really meant to charge external devices, and not just to supply for example a keyboard, allowing to wake up the PC?
Yes. When PC is turned on the phone charges way better.
All my other devices charge normally while PC is turned off: old phone, smartwatch, and wireless headphones.
At least the smartwatch and the headset charge at low rates compared to the FP3. Some powerbanks need to be switched to a special low current mode, in order to recognize them at all.
Can you give an idea of the rate. My phone connected to a 5V USB usually takes 3m to charge 1% i.e. at approx .5A/Hr even though it can provide 2.4A. So 5 hours approx.
Sorry took sometime to reply but apparently there is a limit on how many replies you can send as a new user.
@amoun
When PC is on: approx. 4min to charge 1%
When PC is off: approx. 1h to charge 1%.
I can live with this issue if it is not hardware related to my piece. Tho I’m wondering now if it is somehow related to my issue with Android Auto not working.
My friend is just telling me that his phone (not FP tho) doesn’t even charge when PC is turned off.
Sounds about right 
Did you see my posts above
I noticed it did get better, a bit, then a bit more. Thought it is unfathomable. Apparently I read the charging routine a learning curve for the power unit??? I’ll see if I can find a ref to that.
Things are not as out of sorts as I imagined for you.
All the best
With the same PC or another one? Because depending on the PC, it may not have a port allowing charge when off. E.g, my 8y old laptop doesn’t have any USB port allowing charge when powered off, while the 2y old laptop of a family member of mine has such a port, which btw. allows 1A charging.
Usually PC systems (like this one) never shut down anymore, and so do other devices that are connected to the system. When running Windows, “Modern Standby” could have an impact on these devices, too:
I think you may indeed have to “live with this”. It’s normal, not an “issue”.
In my experience the FP3 requires at least 750 mA to charge at a “useful” rate, that is, input exceeds consumption. I don’t know what the rating of your PC’s USB port would be when the PC is “off”, but it’s likely to be low (as noted by DeepSea), maybe around 500 mA. That would have been enough for my old Galaxy Ace 4 
, but the FP3 requires a higher current to get anywhere.
Don’t forget that a PC that’s supposed to be “off” cannot provide much power to USB as this still comes from the power supply which has no cooling when the PC is “off”.
Personally I use an old 750 mA charger that puts in about 25% per hour which is what you would expect (3020 mAh battery capacity / 750 mA charge current = 4 hours of charging for a theoretical full charge).
Every PC mainboard is supplied with power even after the operating system has been shut down before. The power supply unit does not need cooling due to low voltage, and enough power to charge a device should be available…
Yes that’s basically my point. And it’s not so much voltage (which should be constant), it’s the current rating that’s important.
That depends on the device. As I say, 500mA is fine to charge a headset or watch. FP3 is more greedy.