New Fairphone 2 Bottom Module with an appropriate case

My microphone breaks very often. Is that better with this “alternative module”? Does it fit into the standard slim case?


No, You need a special case, but I’ve never had a mic break.
There were some contact problems with the older revisions, but those are fixed due to newer and better meassurements of the connector.
For the case I have a printed case out of TPU, flxible plastic.
It is not only a alternative, but also gives you USB-C

1 Like

I guess that is because the microphone’s position at the bottom side is different and the USB-C port has a different shape that the case needs to leave accessible as well, right?


Yes that’s the reason.
You can carve out an old case, but it’s not reccomended, because then the connector can’t be propperly supported and the port might wear out quickly


I wonder if mics damage due to water, and I wonder if you could mod the case to have the mic working with the old case.

My old case is on the way out, only thing with Leo’s C-case if that it is difficult to apply/remove and there is going to be dirt under the edges and corners because there is room under the screen and the case on the edges and corners.

I actually plan to do a differnet approach with the case soon, made out of solid PLA, but there’s some prototyping and design involved, that just takes it’s time


Good point, I was wondering if the TPU case would be rigid enough to keep the battery in place.

I’ve never had an issue with that (restart due to loose connection was a concern), but I fell like the USB-C connector is still not enough supported.
You can get rid of dust with canned air pretty easily, but still this problem needs to be adressed as well

When do you think the new case is available?

1 Like

Am currently printing very early concepts to find out how to do this, but it’ll probably take some more days or weeks before I’m satisfied with the results, I will keep posting here


I’ve finally finnished a new case, which is made out of solid material, PLA in this case (pun not intended).
It is made up of two pieces and they are held together very firmly by friction. It still is kinda brittle, so I’ll try printing a new version out of ABS, a very though industrial thermoplastic, which also has a higher usable temperature of ~80°C. I’ve experienced that PLA can deform under heavy workloads like gaming, when the CPU gets hot.



Is this just in your new design or does the original module also keeps a fuse?
This then could also be a cause if bottom modules stop charging. I never took a close look at the original pcb design. I assume it’s a smd chip format.
Btw. what’s the fuse rating?

You are doing a great job Leo. :+1:

1 Like

The new one also has a fuse, made by littlefuse (https://lcsc.com/product-detail/Surface-Mount-Fuses_Littelfuse_1812L200THPR_Littelfuse-1812L200THPR_C207074.html)
It is a reset fuse, that heats up in case of a short and when it cools back down it resets.
The rating is 2A hold and 3,5A trip with a maximum delay of 2s, so it’s rather slow, but also doesn’t blow at small spikes of current.


Sorry, maybe a partially missunderstood what you tried to ask.
The original module by fairphone does not have a fuse, but I decided to include one in mine, because soldering errors, dust or user error could short the power supply and I wanted that extra bit of safety. It does not interfer with the voltage or the maximum current of the charger


Not being much of an expense. I do agree and also would prefer to have this tiny bit of more safety which otherwise could ruin an entire circuit and device at last. I like those self-resetting fuses but did not know they were also available in a chip form. Up to now I only knew about such types.image
…but, erm, well - now I see the same manufacturer…must have forgotten about that.

That’s the tiny little bit of “extra” I very often miss on several goods, let it be a fuse or another screw just to get the unit a bit longer lasting.
Very nice that littlefuse also sell small quantities to guest customers. That’s not very common in the semi-conductor branch.


This is an amazing project, and I would definitely be interested in picking one of these up once the new model is finished!

Finding a case for FP2 has always been a struggle, the Shapeways bumper case does not properly fit for me and it has broken in several corners. Looking forward to the USB C upgrade and a proper, robust case whenever it is available.

Thank you so much again Leo! You are absolutely amazing. You are a new hope for FP2 even as FP3 looms around the corner. I will be keeping my FP2, no desire to buy 3.


@Leo_TheCrafter , I just saw it. How did you do it? Did you get support from the FP company (like mechanical information) or did you use a micrometer?
The PCB shape is obviously different for the FP3, but this is no issue. I can easily send the PCB to eurocircuits, and mount the components in our lab.
Although on the FP3 bottom module there are other components (vibrator, mike). This would require some info from the FP company, or careful desolder-resolder.


I have done everything myself, including the reverse engineering. I have ordered the PCBs from china for a good price. I think I know eurocircuits and I think they are a bit expensive, though probably better quality, even though I never had any issues


I’ll take the eurocircuit costs, no problem! We’re use to work with them.

1 Like

A post was merged into an existing topic: :de: :gb: Fp2 external battery