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1,2 A charger ok for FP2?


#1

Will my Nokia charger with 1,2 A be fine to charge the Fairphone 2 that is said to require a 1 A charger?


#2

I think so. The hardware in the phone should take care of that and limit it to the current that it needs/can work with. I’m using a 2 A charger here. But I never saw details or got information about what chipset is working inside the phone charging the battery. But it works here for me, hope that helps.


#3

To be really sure, you can always contact the support. Since this is only a community forum and the FP2 has not been delivered to anyone yet (it’s only now in the final assembly stage), nobody will be able to answer you with 100% certainty…


#4

It should be, if it wasn’t it would be the only modern phone I’ve seen that isn’t. I charge my old phone with a 2.1A charger.


#5

While I totally agree with you, in the end it’s a pretty easy technical question that could be easily answered for all time if the FP project would publish the full specs of the phone.

Most phones work with similar chip-sets … interesting details would be if it can be charged faster (with the the right cables …) or if it could use a higher voltage over the USB specs (think solar panel). This can only be answered by FP. And the phone is already available as a prototype … so they should be able to answer this publicly.


#6

Well, from a basic electrical point of view the problem could be the opposite one, when you have a charger which provides current to a phone which tends to ask more than the nominal maximum charger current; this because while voltage data normally need to be in strict ranges in order to avoid over/under-voltage problems, the current provided is driven by the load (your phone) so if the latter asks less current than the nominal maximum provided by the charger everything works as expected, while if the phone asks more current than available it could damage the charger (and even the phone could be damaged also).
So these are the scenarios:

  1. Charger with XX V (Volt) and YY A (Ampere) -> Phone with XX V and ZZ (<= YY) A -> OK;
  2. Charger with XX V and YY A -> Phone with ZZ V (<> XX) and YY A -> NO!
  3. Charger with XX V and YY A -> Phone with XX V and KK (> YY) A -> NO!

In this case if FP2 needs a 1A charger and you’ve got a 1.2A charger you fall in the first case so it’s OK :smile:


#7

DjDas, are you sure about your 3rd scenario? look here:


#8

I think it all depends on the lipo charging chip inside the phone. It needs to be able to provide a constant current and a (higher) constant voltage to the battery during the charging. The “usb charger” (it’s not a charger, just a power supply) is just input for this chip … and the “lip charging logic” chip inside has to be able to handle this “input”.


#9

@bonpotiron: I was writing about “basic electrical point of view” scenarios don’t taking into account USB charging specifications :smile:
This in order to avoid confusions because you asked if a 1.2A charger is right for a 1A phone :smile: so your case is 1)
Normally USB devices (chargers, cables and phones) should honor USB specifications, in which different charging currents can be asked to the charger or to a USB host depending on various hardware scenarios (including USB cables configurations) but this is a more complex stuff I don’t want to go deep into, Google (or DuckDuckGo) can do better than me :wink:
Bye!


#10

As 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%


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#11

Hope it’s ok reviving this thread.

Firstly I have a 2A charger - I think the consensus is that’s ok, the phone will draw the current it needs? It charges really quickly!

Secondly, I find it easier to leave it plugged in overnight. I’ve read loads of general phone threads of people not liking this, but I find it hard not to. Does anyone actually know if it hurts the battery at all?


#12

It depends on the charger technology on the phone side. Because nothing is published about this … we can only guess. I guess: It will be good enough and will not hurt. A few years ago technology was much worse.

Standard battery disclaimer (people in this forum just like to give extra careful unasked advice): Just don’t place it near something that could somehow start to burn easily because batteries can get really warm while recharging. So don’t put your phone in a nest of kleenex while charging it over night :slightly_smiling:


#13

Have you ever read that Apple forum with the flame war on this issue? I’m glad I can even ask the question on this forum! :slightly_smiling:


closed #14