FP is a small company and doesn’t have the resources to test all chargers. But there is a community list of working chargers.
You can get a charger in FP’s shop, but not shipping chargers automatically with every order reduces e-waste alot.
That is true. Some companies even try their best to make sure that their phones and chargers are not compatible with other phones and chargers. Just so you have to buy their charger/cable after the first one broke (which it was designed to do after warranty ran out).
I’ll put the link to the list of chargers in the first post to make it easier to find.
I’ve been having this screen unusable issue on some chargers on my Fairphone 2, so I decided to buy a USB power meter. In my testing the screen is still usable if the voltage stays above 5V when a current is drawn.
On the chargers where the screen doesn’t work while charging, I’ve been finding the voltage is dropping as low as 4.80 and possibly slightly lower. When no current was drawn these USB outlets give out 5.0 V. With the chargers where the screen is usable during charging the output voltage is normally closer to 5.2V when no current is drawn.
I’m wondering if there’s something in the electronics of the such that when the voltage goes below 5V, even just 0.2 V (a 4% reduction) is enough to cause the touch sensitivity to no longer work.
I have seen a comment from a user on this forum that received a replacement phone from Fairphone, and only one of them (I don’t recall if it was the new one or the old one) had this problem. So it appears that this problem doesn’t occur on all phones.
It occurs on my phone though, much to my chagrin. It would be good to test replacing the bottom module and see if that fixes this issue. Anybody willing to sacrifice € 20 for science?
Well, of course there are no randomized double-blind studies yet, but I think it’s save to say that there is about a 99% correlation with the used charging equipment (charger, cable, plug) when it comes to this issue.
I wouldn’t invest in a study that tries to determine how much of the last 1% is related to the bottom module.
I am on version 1.9.3 and got FP2 today. If the phone is plugged to power, the touch function of the display freezes shortly while using it. Pressing the power button twice (first to lock the phone and second to bring it up again; the display needs to be completely dark before unlocking) makes the touch working again after it freezes again shortly.
It is really strange, that this problem is only present while plugged to power and loading the battery.
Yes, I have tested with 4 different chargers. Only a very old one from Sony seems to work. I had a look into the userlist, they mentioned the 2-Port-Anker (24W) I have, which had the worst issues of all chargers I have tried with, it should be removed from the list.
Also not working is my Motorola-charger. While phone keeps being responsive the charger-LED turns off and on again random several times a minute.
But, is it possible, that the Anker would work with a different cable? I have tried it only with the cable it shipped with.
Looks like the Motorola charger cannot deliver constantly enough current. Many chargers are rated to deliver up 1 amp of current, which must not necessarily mean permanently full 1000mAh.
FP2 can draw up to 1300mAh depending on battery state.
Also a proper cable of decent quality should be used. Try different ones on one charger maybe to see different results.
Standard usb cables are interchangeable.
Someone who also faced this trouble here brought up the thought that if the voltage while charging would drop far below 5 volts the display could become unresponsive. I think up to now this was not reliably confirmed by anyone. Myself had not yet the option to test this. I only used the free app “ampere” to have a rough estimation on charging conditions.
This is just a message to not give up hope. I’m pretty sure I’ve posted in this thread before. At least, I have been following it closely because I have had the same problem. Until one day. Last week. I could use my phone. While it was charging.
Same phone, same adapter (from a Samsung), even the same plug in the wall. Now, the touch screen works while charging! Hallelujah! I wish I had a solid technical explanation. Maybe something was tinkered with in an OS upgrade? It’d be interesting to know if others had this happen.
Now if only it would stop randomly rebooting, we could have a really satisfying relationship.
The reason for such behaviour is:
the charger emit high frequent noise with the current and if that reaches the FP2 it makes the phone unusable. In my opinion the FP2 is not ok, because two dozen other phones work flawless while charged with the charger in the images.
the reason is not:
a cable with only two wires for the current. Charging works normal without data-wires.
is shown in the picture. Use a calble with such ferrit-denoiser (No clue what the english term is …). I tried to make it clear so I used a cable for 1 Euro and a ferrite-ring from another cable.
The charger: is a cheap Huawei one 5 years old …
Now for the images:
The charger with orgnal cable - the FP2 gets charged but is unusable
the charger with a pimped cable
(without this thing the FP2 is unusable too with this cable)
The term for this thing is “ferrite nuclei” and it works as “low-pass-filter”, that means, it lets not pass signal with a frequncy but DC. If you built a cable like me, then let the wire pass 2 times (or more). And set it as near to the charger as possible …