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HappyDude20

macrumors 68040
Original poster
Jul 13, 2008
3,674
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Los Angeles, Ca
I’m wondering if a 5w charger for Apple Watch will charge more slowly than a 12w charger?

The 5w obviously came with my iPhone and the 12w came with my iPad.

I heard Apple Watch doesn’t support fast charging so am I correct in guessing that both charge it pretty much the same?

I also have a 2.4A charger in my car from Belkin; one of those that you plug into the cigarette lighter. And in my opinion in the car this device charges it abysmally slow. Maybe 3% per hour.
 

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BlankStar

macrumors 6502a
Aug 13, 2004
777
840
Belgium
I remember reading that the Apple Watch only draws 1.5-ish Watts on average while charging and since the watch "pulls" the power from the charger, it doesn't matter what the maximum wattage is that the charger can handle.
 
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Fayette3001

macrumors member
Jul 27, 2020
71
45
Bavaria, Germany
As said before the watch has a limit to the wattage it can receive and it doesn’t have fast charging capabilities so either one would charge all the same.
 

Julien

macrumors G4
Jun 30, 2007
11,836
5,434
Atlanta
I’m wondering if a 5w charger for Apple Watch will charge more slowly than a 12w charger?

The 5w obviously came with my iPhone and the 12w came with my iPad.

I heard Apple Watch doesn’t support fast charging so am I correct in guessing that both charge it pretty much the same?

I also have a 2.4A charger in my car from Belkin; one of those that you plug into the cigarette lighter. And in my opinion in the car this device charges it abysmally slow. Maybe 3% per hour.
Just to add the Charger is in the Watch (same with almost all Lit-Ion devices). You are asking about using a 5W or 12W power supply (just about everyone confuses this and calls the power supply a charger). The Charger determines the amount of power allowed into the battery.
 

HappyDude20

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Original poster
Jul 13, 2008
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Los Angeles, Ca
That’s insane that you guys are telling me I can go either or (of the ones I pictured) and it’ll charge at the same rate.

This morning I awoke to my watch at 23% and used the iPad brick ‘charger’ and to get it to 100% took an hour and thirty minutes.

Not bad but crazy you guys are suggesting it’ll be exactly the same with the littler iPhone one.
 

compwiz1202

macrumors 604
May 20, 2010
7,389
5,745
I will have to charge it with my one power bank tonight that shows the V and A draw. I don't know why it seems to be some ancient Chinese secret to find the input V and A for devices sometimes. I searched for at least 15m the other day and found absolutely nothing on the input power for an Apple Watch.
 

HappyDude20

macrumors 68040
Original poster
Jul 13, 2008
3,674
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Los Angeles, Ca
All I know so far in having an Apple Watch for 3 days now is that the 12w ipad brick charges it from 23% to 100% in 90 minutes.

And I also know that my 2.4v cigarette car lighter adapter charges it absurdly slow at about 3% gain every hour while driving.
 

chrfr

macrumors G5
Jul 11, 2009
13,591
7,133
And I also know that my 2.4v cigarette car lighter adapter charges it absurdly slow at about 3% gain every hour while driving.
You mean amps, not volts.
A 2.4 amp USB charger is the same power output as a 12 watt USB charger. I'd suspect that your car charger either isn't performing to specification or your don't have a good magnetic connection while you're driving.
 

HappyDude20

macrumors 68040
Original poster
Jul 13, 2008
3,674
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Los Angeles, Ca
You mean amps, not volts.
A 2.4 amp USB charger is the same power output as a 12 watt USB charger. I'd suspect that your car charger either isn't performing to specification or your don't have a good magnetic connection while you're driving.

I just looked at the little cigarette lighter device and it says 3.1 amp. And it has 1 regular usb outlet and another usb type c outlet. My iPhone Plus charges normally when I drive but not my Apple Watch. My guess would be that it’s because I’m using a third party Apple Watch charging cable and the magnetism is admittedly weaker than the original that came in the AW box.
 

Significant1

macrumors 68000
Dec 20, 2014
1,637
758
That’s insane that you guys are telling me I can go either or (of the ones I pictured) and it’ll charge at the same rate.

This morning I awoke to my watch at 23% and used the iPad brick ‘charger’ and to get it to 100% took an hour and thirty minutes.

Not bad but crazy you guys are suggesting it’ll be exactly the same with the littler iPhone one.
It is not crazy, when you understand that there is control logic built-in to take care of the battery, which handle the charging process and determine how much power to draw and when to stop. 5W could charge the tiny battery in Apple Watch much faster if the battery could handle it and it wouldn't reduce battery life expectancy significant.
 
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HappyDude20

macrumors 68040
Original poster
Jul 13, 2008
3,674
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Los Angeles, Ca
So I just tested the 3rd party Apple Watch charger that I was using in my car; the one that only charged the Watch 3% per hour while driving. I connected this 3rd party cable to the 12w little white brick to my wall and began charging my Apple Watch when it was at 23%, just like before with the cable that came with the Apple Watch and after 90 minutes with this 3rd party charger my AW is only at 66%. It’s obvious this 3rd party charger sucks. Aside from it weighing less, the magnetism certainly feels less strong as well.

Now I’ll try to charge my AW in the car with the original charging cable and I expect better results.

Long story short, I’m going to throw away this 3rd party charger I bought on eBay for $10.
 
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