Charging the FP2 / cable problems

If your new cable is able to charge but not connecting to the computer, I guess your new USB cable is a charging USB cable which is two threaded. You have to make sure you have a DATA USB cable for connecting to the computer. A DATA USB cable is four threaded.
Mind you for charging in the car you only can use a DATA USB cable with your Fairphone.

I also have problems to charge the Fairphone 2 with my car adapter, unless which kind of cable I use. I tried several different cables which all charge all my other devices in the whole family without any problems, tablets, smartphones and powerbanks. Only the FF2 ist making trouble.
Because the Battery of the FF2 ist not at ist’s best, I need a possibility to charge the device on the road. The powerbank does the job very well. I bought it for my old device and I’m glad now to own it.
Normally the electronic of the battery should be responsible for the management of charging, perhaps there is something out of the standard.

Edit: Yesterday I tried a second car adapter with another cable which worked, so I have now one solution to charge my phone in the car. Have to buy a new adapter for my second car.

I’m going to call in @borjan to see if he can weigh in on the status of this issue.

I have four different cables, and I can use my phone while loading with two of them. Really seems like some oversensibility of some cables.

For what it’s worth I’ll add my experience:

I charged my FP2 once with my old HTC charger, which worked fine. Now I’m sitting at work trying to get it to charge with no success. I tried a USB cable to the computer and a cheap no-name charger.

Edit: It’s charging now on a different computer with more power I guess =( But it charges very very slowly

Is it worth merging these two topics:

as they seem related.

Did you noticed any differences in charging speed and have any clue, what the highest current (or better measureable: power) is, the FP2 can drain from a high speced charger?

Do you say, the FP2 charging electronic comunicates actively with the electronic of the charger?
Can you provide a link for this as it is quite new to me?
For PC-FP2-USB-connection sure. But between FP2 and charger??

Up to now I thought the charger just have a smart electronic to stabilize voltage and provide as much current the receiver needs. This should also work with a simple resistor in place, which obviously deosn’t know about a protocoll HOW it should transform the electrons to heat…am I wrong?

To my knowledge for charging you just need pin 1 and 5 to make use of the charger.
Pin 2+3 are for data transfer only (PC etc.) and pin 4 only if you want to tell the client to provide power instead of consuming (e.g. for OTG)

So for what exactly does it stands for?
Until no other convincing links I see this label as some kind of “nonsense” as I also see e.g. the label “Skype certified” on Notebooks nowadays (as nearly all notebooks can run skype)…

So it’s no offense, but either I am wrong or your claims are not quite true…

But this discussion is independent of the cables: a full 4-wired cable is for sure better than a cheap 2-wire cable as here some shielding can play a role…
Cheers, Robert

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That’s what I mean’t, no active communication.

What makes me wonder is that I can charge the phone with my USB Connection of the PC which provides only 500mA, but not with my car adapter, which is said to provide up to 2.4A. Every no name AC-charger from 800 to 1300mA I own works fine. The car adapter works with every other device we own, also tablet and powerbank.

As I also wrote here I got my FP2 today I tried my old original FP1-charger for it, which worked!

Power consumption during charging, phone power off (measured with a power meter):
FP1: P=5.5W => 1,1 A if 5V is provided => calculation: 1h50m for a full charge (2000 mAh), ~2h in reality!
FP2: P=7.7W => 1,54 A if 5V is provided => calculation: 1h36m for a full charge (2450 mAh), if linearity is assumed

Thats only with the original FP1-charger to give you some minimalistic values, what the FP2 should do.
Most likely the power is limited by the charger (output 1.0A@5V), which should be already for the FP1 at his limit. I am quite surprised, that he can deliver 150% of its designed values.
(btw: it gets noticeably warmer than with the FP1 and makes some noise. Hope it will not die)

Edit: after beeing commented here:
If we multiply numbers with 80% efficiency of charger/FP-electronic we end up at FP1=0,9A and FP2=1,2A, which would mean full charging time would be FP1=2h13 and FP2=2h03m.
Charging of Li-ion battery is quite linear in time up to 90% capacity.


I didn’t get my FP under 50% for now, so I cannot say that. It charged very quickly with both chargers.
It’s very hard to measure the charging current, because if you put a multimeter or any measuring device inside the line, the resistance of the cable is higher and the charging current will be lower… :confused:
When I’m home again, I will try to get better measurements.[quote=“therob, post:31, topic:11668”]
Do you say, the FP2 charging electronic comunicates actively with the electronic of the charger?Can you provide a link for this as it is quite new to me? For PC-FP2-USB-connection sure. But between FP2 and charger??
No. Sorry, English isn’t my first language. :wink:
I did mean, that there is a “protocol” for the device to recognise the charger. So it gets the information about the charging current by checking the mentioned resistor and raising the current until the voltage drops a defined threshold.
This is the “Battery Charging Specification” (see here), but I don’t know, if the FP sticks to this specification.

As I mentioned, there are several different specifications (better word than “protocol” ;)) for charging, so the charger needs to recognise the device and stick to the specification the device complies to. There is more logic than just putting a resistor between the data lines to use the charger with more than one device.[quote=“therob, post:31, topic:11668”]
To my knowledge for charging you just need pin 1 and 5 to make use of the charger. Pin 2+3 are for data transfer only (PC etc.) and pin 4 only if you want to tell the client to provide power instead of consuming (e.g. for OTG)
As you can see in the specification, the data lines are used to indicate the device that it may take energy from that port. The USB specification says, without any information the device is only allowed to consume 0,5 mA. I don’t know if all devices do that, but the FP2 obviously does, so you’ll always need a cable with all four lines (5 V, GND, D+, D-; ID is only for OTG).[quote=“therob, post:31, topic:11668”]
So for what exactly does it stands for?
In contrast to Apple, most devices with Android comply to the named standard, as far as I know. (We didn’t get that information yet!)

Sorry, these measurements are not significant if you measured at the primary side. The phone doesn’t charge linear at all (read about li-ion charging!), also your assumption of 100% efficiency is very bad (70% are a lot better). In addition to that, most cheap power meters do not consider the power factor correctly :frowning:

I did an edit to my post above.

Ok, after trying two more cables, the fifth worked!

The same problem here. Tried different chargers/cables and also charging by PC. Phone does signal a charging battery (lightning strike in battery symbol), but the “battery menu” says ‘battery not charging’… This seems odd.

Hope this can be solved whitout buying an extra charger?

It seems that a charger 5v and 1A will do the trick. But it will only work with a right cable. As @palmada wrote: his fifth cable worked.
So ttake a drink, take a deep breath and go on trying.

(I have a charger 5v and 2.1A and I can’t get it to charge my Fairphone 2.)

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Hey there,
I’m having some issues with my battery and/or the USB port. Actually there are two problems I have but maybe they are related somehow:

  1. issue: when my FP2 is charging through a socket after a time it starts disconnecting and connecting again every second or so and basically stops “normal” charging. Today for example I plugged in at about 40 % and up to 60 % it charged just fine and then it started going crazy. I tried different cables and different USB power adapters which work perfectly on all my other devices but it is the same with each of them.
    Strange enough so far I didn’t have any problems while charging through the USB outlet on my laptop. Problem there: it takes AGES!
    To me it’s some kind of mystery. At first I thought it’s “just” a normal defective contact/loose connection on my Fairphone but now I wonder if it maybe is a software-related problem.
  2. issue: I read in the forum that people are quite happy about the battery life of their FP2 - mine however barely lasts until late afternoon and I’m not doing anything specific which kills battery life.

Anyone having the same problems?

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I’ve tried 2 different chargers, both are 5V-1A.
I don’t have other chargers :slight_smile:

I have the same problem, some chargers, even if they meet the specifications of 5V and 1A, do not charge my Fairphone, although the charging battery (lightning strike in battery symbol) symbol is shown. Additionaly my battery life is rather unsatisfying, it barely lasts 15 hours.

Is this a software mistake or how can I improve the battery life?

Please try both chargers with other cable.
Do you have a data cable? To check if the cable is right,
try to charge through the usb-port of the computer.
If it works with the computer, it should work with a charger.
But somehow the FP2 is having a problem with a lot of chargers.
I have no clue why.

How much use is it getting in 15 hours? I guess time is only relevant if it’s sitting in your pocket.

Well for 8 to 9 hours I’m barely using it, the rest of the day I am listening to some music, checking my mails, replying to some messages, etc. All my connections except for WiFi are turned off.