How to meter measure charge watts i0S 18 iphone 16 Mag Safe charger

Question

Level 4

3,365 points

How to meter measure charge watts i0S 18 iphone 16 Mag Safe charger

Hi, I'm trying to figure out how to measure the charge WATTS (or Amps Volts) my new "Apple MagSafe Charger Wireless Charger with Fast Charging Capability" and my new iPhone 16 Pro Max (iOS 18.0) are performing during charging

my normal USB meters don't seem to work connected at the charger end (USB-C) -- I think they need to be connected on the opposite end which of course the Mag Safe doesn't have

I tried "Ampere Battery Charging Check" app installed on my iPhone (downloaded off the Apple App Store) with dismal results: 8.91 WATTS -- 1605 mA -- iPhone battery is at 30 percent

I was expecting closer to the Mag Safe's advertised speed: 25 watts -- I know this is theoretical for the iPhone and Apple Mag Safe Charger, but it is really far off -- and this is WHY I buy USB meters to see what is actually going on with my chargers and devices, including testing charging cables and ports for best performance

either the app is useless (in my configuration) or the hardware is not performing to spec

I researched where Apple is actively restricting 2nd party access to the battery -- more aggressively since iOS 17-18 -- but I just want to simply check the charging performance of my new Mag Safe before I buy another one

Using my "USB Power Meter PD 3.1 Type-c Tester Digital Multimeter Current Tester" with a newer "Apple 35W Dual USB-C Port Compact Power Adapter" I meter 27 watts (wow)

my Mag Safe was purchased new from Amazon Sept 2024 (ships from and sold by Amazon) so I am pretty sure it is legit item (box looked good and was factory sealed)

WHAT WOULD HELP ME OUT:

an App recommendation I can trust to measure the watts charging through Mag Safe on iOS18 and iPhone16
Anyone who has successfully metered their Mag Safe charger -- and how you did it

writing down batt percentages and charging times -- and doing math problems (or intuition) -- probably won't help my pea brain solve the problem -- a simple USB meter should yield the answer in a few minutes of observation...

Posted on Sep 29, 2024 11:51 AM

Reply

Answer 1

Top-ranking reply

-g Author

Level 4

3,365 points

Oct 1, 2024 10:15 AM in response to -g

CONCLUSION:

I don't think the apps are the way to go for getting reasonably accurate results of how many Watts (amps volts) your phone and iPad chargers are outputting (or the numbers your devices are actually drawing from the charger)

but the app did help me red flag the complaint and eventually figure out my new iPhone Apple branded Mag Safe charger (model a2140) is the older 15w version (sold by and shipped from AMZ)

it is not not the new current 2024 A2580 or A3250 model which can output 25w to my iPhone 16 Pro Max

how to distinguish between old 15w and la… - Apple Community

I'm returning my a 2140 to AMZ and receiving my a 2580 tomorrow directly off apple's web store

Reply

Answer 2

-g Author

Level 4

3,365 points

Sep 29, 2024 4:26 PM in response to -g

Soon as my iPhone needs recharging — I can test the app while charging from my apple 35w charger - my usb meter works on that configuration

and should offer me a real-world clue how accurate the app is displaying…

Reply

Answer 3

-g Author

Level 4

3,365 points

Sep 30, 2024 10:40 AM in response to -g

APP IS GROSSLY INACCURATE

may just need updates, but first impressions as they say...my test was unscientific and my technical knowledge limited to years of observing such things -- your milage may vary

ran the test 2 times at 50- and 60-percent battery using Apple 35Watt charger and Apple USB-C cable that came with my iPhone 16

50% battery:

USB meter read: 22w (14.675 volts, 1.5031 amps)

App read: 12.7w

60% battery:

USB meter read: 15.7w (14.769 volts, 1.0680 amps)

App read: 9.5w

Reply

Answer 4

-g Author

Level 4

3,365 points

Oct 7, 2024 4:07 PM in response to -g

CORRECTION

I saw Max Tech on utube metering his Mag Safe chargers by plugging his meter into the power adapter and the mag safe cable into the meter.

I tried it on my iPhone 16 Pro Max (at 40% battery) and it appears to work except I could get the watts above 11 when I expected closer to 25w on my iPhone16

I don't have this figured out yet ... I'm just saying

"It is the theory that decides what we can observe."

- Albert Einstein

Reply

How to meter measure charge watts i0S 18 iphone 16 Mag Safe charger

Similar questions