How to disable fast charging mode on FP4

Do you have small in-ear headphones (ear phones)

With my over the ears set an adapter would hardly be noticed.

However I 'm using an FP3 anyway so


It wouldn’t, but it might be good for longevity.

That’s good to know, due to the notification I’ve assumed it was a bad thing.

I usually had Quick/Fast charging disabled on my Samsung A50, because I prefer the battery to live for a longer time and I’m usually not in a rush to charge. When I was in a rush I’d switch Fast charging on and after I took my phone off the charger I’d switch it off again.

Quick/Fast charging puts more strain on the battery and leads to it wearing out faster.
It’d be nice to be able to disable the option so I don’t need to use two different chargers depending on if I can leave my phone charging leisurely or need a quick boost because I’ve gone a bit too long without charging.

Hi and welcome to the forum.

Try not using a fast charger, (QC3 or QC4 etc. ) maybe use a USB A port on a computer which provides only 0.5A/hr

I use an old 12v to 5v car charger, which usually takes well over 5 hours to charge my 3000mAh Fp3 battery

No, they sell a charger with 2 options. One for fast charging, one for regular charging. The official cable has a detachable part, so you can use either of the connections. But I wasn’t aware they actually warn against fast charging. Good to know.


18 Watts isn’t slow, that 5 x 3.6A


My Fairphone didn’t show fast charging in the status bar. I don’t know what constitutes a “safe” charging speed. I personally don’t think there’s a huge difference for the lifetime of a battery, also because the phone itself throttles the speed, also non-Fairphones. But I izz no expert on the matter.

I’m pretty sure too that Fairphone use a ‘safe’ charging speed, after all the batteries are guaranteed for two years. :slight_smile:

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Or not. Mixed calculation. Common practice in finance :wink:

The FP4 will happily charge at just below 18W until the battery reaches 50% percent full, if the temperature and charger allow it. After that the speed will steadily decrease.

So to keep the battery healthy while using the official (fast) charger, something like acc is needed to limit the current / voltage.

Thanks for your tips but my point is that I want to use the same charger for fast and slow charging…as I have been able to do for years (not on Fairphone to be fair). And I have no wish to have two charging cables by my desk or bed, one attached to a old charger and one to a newer one.

I have been able to disable fast charging on my last several phones which is why I’m confused and disappointed that it doesn’t seem to be part of vanilla Android or Fairphones version of Android - whichever applies.

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Yes the Fairphone OS is a vanilla Android with a few adjustments, but not one for battery charging it seems.

See anyway

According to the Ampere app, on fast charging (4.4V , 1930mA), the battery of my fairphone 4 heat up to around 27C vs 23C on slow charging. Around 80% of charge, the mA decrease steadily and the temp decrease as well. I’m using a fast charger from samsung (adaptive fast charging).

The recommended operating temperature for a Li-ion battery is between 20 to 50C.
Is fast charging really that bad for the battery ?

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No. It’s all relative. Fairphone provide a charger and and algorithm to charge the phone quickly, which is what most people want. They also guarantee the battery so clearly it is not a ‘bad’ thing.

However you will read opinions, and it makes sense, that if a battery is stressed it is likely to degrade and temperature is the sign of stress.

So charging slowly is less stressful and the battery may well last longer.

It’s whether this extra longevity is significant enough for you to consider worth pursuing.

Equally a cold or depleted battery needs a lot of care to get it up and running again and that process can be stressful.

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