Charging while powered off slower

Help Fairphone 3
1

Hi

I have noticed that the phone (FP3) charges faster when it is on.
10% to 95% in 1:30 hours while on vs 2 hours while off.
The charger is a rapid charger (15W) is this normal?
Does rapid charging only work when the phone is on?

Thanks

Mo

2

Just as a side note, the Ampere value is the one that determines charging speed, not the Watt value. 3 A should usually charge it in 1 hour, 1 A in 3 hours.

1 Like
3

I am aware of that, however, with the same ampere the phone charges slower while off.

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4

Just curious: why would you turn off your phone while charging?

5

I turn my mobile off while I am asleep.
Just happened that I took a two hour nap twice this fortnight. Each time the phone would be barely over 90% from 10% or 12% when it was plugged in.

6

That should be due to the FP3’s “smart” charging, which switches to slow for the last 10 percent of capacity to go easy on the battery. The mechanism is proprietary and cannot turned off by the user.

7

Then how is it faster to charge with the same charger when the mobile is turned on?

8

Sorry for the delayed reply.
Same 15W charger, from 10% to 90%
Off one hour 45 minutes
On one hour 20 minutes