Thanks for your story. I really am hoping for a better experience and by now a few reboots per week dont even sounds to bad. But 4 every 12 hours is really not working.
I am wondering whether it would hurt to turn of the security pincode for the simcard so it can restart automitically after a reboot?
Well, it would hurt the security obviously. 
Pro:
Rebooting would be much more comfortable.
And if the phone reboots without you noticing it, you will get reconnected. This way it can’t happen that you are not available for maybe hours and you don’t know it.
Con:
Whenever and wherever your phone is unattended or if it’s stolen, it is open “for inspection” by everyone.
At the beginning (2,5 years ago), my FP2 also rebooted quite often. The reboots stopped when I switched 4G off and started to use only 3G.
As BertG already wrote, this might be an important security issue.
What I did and what you might do is to switch off the SIM pincode and set a unlock pincode for the phone (you might also use a pattern or a password). The problem is that you’ll have to enter it every time you use the phone. Well, I got used to it…
thank you for your thoughts, my thoughts where similar and I do think it is kind of a good idea, given the circumstances
set an unlock pincode for the phone will cover the securety issue, great idea
switching of 4G wont work, my fp has no simcard in it at the moment but still reboots appr 4 times day. without me even being neir it 
Have you happened to find this thread already?
I don’t know, if that is still a valid solution, as they posted in May 2017, that they solved this issue with the slim cover. Still, you might have an old one. So it’s unclear if it’s going to help, but it definitely won’t do any harm.
Well then, shame on you 
It´s the only way left for it to ask for more love and attention by you as It cannot speak. Maybe the solution is to give more of both. 
Spreading more positive vibes could help too… 
Hi…
I must say I completely understand your frustration… I went through 3 FP2 myself… Still having random reboots, battery life sucks, my new transparent slim case is missing a piece (cracked by itself after a week of use)… It gets hot, applications don’t run (god knows why) etc.
I HAVE TRIED EVERYTHING suggested on this forum… Nothing changed, I know just hate my phone (but still in love with the idea behind it) so I’m buying a new phone now…
So sorry to say but sometimes it doesn’t get better whatever you do…
For me putting a piece of paper (two actually to get the right thickness) below the battery to push it tighter against the electrical contacts reduced the amount of random reboots a lot.
I aggred with this solution too. Fairphone support give me a little shim to avoid this issue but it was not enough tight (still reboots), so I cut a little plastic of an old sim card.
If fairphone designer would stop this issue for good they need to really tight dimensions on batterie case or put a cable for a connection (no spring with 1 touch contact).
It would take a spring at the bottom-side of the battery (where you have to put the paper), pushing it against the contacts. That’s the way it is working with every other battery compartment for AAA, AA, … D cells. Four tiny spring-contacts pushing the battery (especially just on one corner) can - obviously - be troublesome. Even more so, when the battery is a rather large (dimesion-wise) one and the battery compartment not exactly a tight fit.
sorry for not replying earlier.
but just now I opened my phone and decided to check all the little screws from all the different modules, I could tighten some of them a little bit. And although my fp does survive the loose batterij test, I did put a piece of an old simcard in between the battery and the compartment.
to be continued…
Hmmm I hour past and 1 reboot happened 
and another reboot has happened, I think I can not solve this
Hi,
Really sorry to read that… Just a though, have you explore a software issue? Maybe one of your apps is causing these reboots? Some of them are draining battery (see the discussion here).
Do you think it is possible?
Is your battery moves a little in the case? If is the case you has to put a better shim. The battery has to be really tight.
I had reset my phone to factory reset without any other apps (only my googe account) it still reboots so I do not think that that is the issue
I did try that but that also did not end the reboots
My phone will be sent to hq I hope they can solve this
.
I will keep you updated
Hi again… Having tried everything I have to say : sometimes there’s nothing you can do… It’s pretty disappointing.
And of course pushing battery with a piece of paper shouldn’t be a solution… You kind of expect that the battery fits your phone!
Hi
After two months of testing, shims doesn’t work is even worse. When i put my phone in the car, sometimes the car vibrates too much because I’m too lowest shift.With the vibration, the phone reboots. So now I removed all the shims. The company need to find a better solution than shims or replace the component.
I think if they would like to solve this issue forever, they need to redesign the phone. So not a solution for this year.