B737 USB power

RooFlyer

Veteran Member
Joined
Nov 12, 2012
Posts
25,736
Qantas
Platinum
Virgin
Platinum
Star Alliance
Silver
On a recent B737 J flight (can't ID the aircraft, sorry), I attempted to charge my iPhone 12 Pro via USB at the seat. It didn't start charging. FA confirmed the power was on (green light on) but quickly added (like she's dealt with the issue before) that the power delivery isn't sufficient for iPhones.

That's a bit surprising (given that phones/iPhones are likely to be the most common item plugged in) - but I recall some discussion on a similar issue before.

Is it the case?
 
iPads could be problematic. Phones makes zero sense.

The issue is most likely the plug itself. Gunk in it. Outright broken. So there may be power, but it simply isn’t getting to the device. FA should have added it to the cabin log, but given that retort, I guess she did nothing.
 
I have noticed that the power delivery isn't sufficient to increase the charge level my iPhone if I'm using it at the same time, which is possibly what the flight attendant was aware of. (The same happens when connecting to the USB port on my old laptop). Even if I'm not using the phone, the charge speed is very slow compared to using the AC adapter or a USB-C cable. But it still shows the little lightning bolt and it at least stops the level from dropping. If there was no power at all, well, there's no power - it's not that complicated ... as @jb747 said likely gunk in the outlet or similar.
 
On a recent B737 J flight (can't ID the aircraft, sorry), I attempted to charge my iPhone 12 Pro via USB at the seat. It didn't start charging. FA confirmed the power was on (green light on) but quickly added (like she's dealt with the issue before) that the power delivery isn't sufficient for iPhones.

That's a bit surprising (given that phones/iPhones are likely to be the most common item plugged in) - but I recall some discussion on a similar issue before.

Is it the case?

It’s an iPhone thing (and I assume equivalent Samsung thing). They suck a lot of juice.

Although even though it isn’t charging, that’s not to say it’s not getting power, so will likely at least maintain current charge or possibly even gain a few % over a few hours.

Same thing happens if you plug it in to a TV USB socket or similar.

IPads are even worse.

I’ve had this on a QF 747 seat so is nothing new.
 
I’ve had this on a QF 747 seat so is nothing new.
Yep - and this is why I prefer aircraft that have actual AC mains-type power outlets (even if's a US type) - they will charge phones so much faster if fitted with these outlets and you use your power brick (AC adapter).
 
The Frequent Flyer Concierge team takes the hard work out of finding reward seat availability. Using their expert knowledge and specialised tools, they'll help you book a great trip that maximises the value for your points.

AFF Supporters can remove this and all advertisements

I suspect the power output from the USB ports on the 737s is under 10W given how slow they charge. Quite possibly as low as 5W.
 
But it still shows the little lightning bolt and it at least stops the level from dropping.

No lightning bolt for me, and it did charge when I then moved to the spare battery I carry with me. So 🤷‍♂️

If there was no power at all, well, there's no power - it's not that complicated ...

OK, with you so far .... :). Point of posting though was to see why there was no power & see if the USBs are known to be under-powered, and it looks like they are.

I suspect the power output from the USB ports on the 737s is under 10W given how slow they charge. Quite possibly as low as 5W.

Yes, there was discussion along these lines a while ago, but I couldn't find it.
 
I think this is a thing. Had very poor charging with USB on 737's myself (with a Samsung "thing" lol) but yeah it sucks a lot of juice, so I wasn't surprised. It did charge, but just very little, so I definitely suspect the output was just not up to the latest hungry devices.
 
I've tried to use the 737 J USB socket several times to charge my iPhone with zero success. I suspect they're rated to 5W but delivering a little less, and iPhones later than, realistically, the 3S are rather pernicketty about their supply current.
 
Quite possibly as low as 5W.
Iphones easily charge using 5W which is 1.0A
Apple makes usb 5W chargers.67C81B84-385A-465C-8961-251EE6A8AA08.jpeg

@RooFlyer
What iOS version is your phone?. And are you using a third party cable.
There is an esoteric issue with iPhones where Apple patched a security hole discovered when the FBI found a way (via a third party solution) to hack into a locked phone. The security hole is the lightning port. Look up USB restricted mode. Affects iOS 11.4 and above. Sometimes it also restricts charging.
 
Last edited:
I've given up on generic iphone cables and pay the exorbitant rate of the Apple ones - if it is generic that may be the issue
 
I generally use an iPad on flights. My iPhone charges albeit slowly from the USB port. If there’s no AC port or if it is not working, I can fall back to using my battery pack to charge my iPad if needed.
 
I generally use an iPad on flights. My iPhone charges albeit slowly from the USB port. If there’s no AC port or if it is not working, I can fall back to using my battery pack to charge my iPad if needed.
Better to use the AC charger and cable for higher power iDevices.
 
I have the latest iPhone and it does charge albeit slowly using the USB port. If I am using the AC port for the iPad I don’t have much choice unless I have access to the neighbours AC socket and they are not using it.
 
What iOS version is your phone?. And are you using a third party cable.

iOS16.5. Type of cable I used? NFI. Its a cable. With a lightning at one end, USB A at the other. It charges fine from just about every source, except on this plane. So then I used the battery I cart around everywhere.

I am totally disinterested in having to know what charges from where, using what make of cable etc. Stick one end into positive potential, the other end into negative potential and just carry some electrons between the two, FFS.
 
Last edited:
Using official Apple cables charging works for me with the latest iPhone albeit slowly.
 
I am totally disinterested in having to know what charges from where, using what make of cable etc. Stick one end into positive potential, the other end into negative potential and just carry some electrons between the two, FFS.
Well, there you go. That's the problem. Apple use AI to detect your level of interest, and the charger varies it's output accordingly.
 
I have the latest iPhone and it does charge albeit slowly using the USB port. If I am using the AC port for the iPad I don’t have much choice unless I have access to the neighbours AC socket and they are not using it.
You need a charger with multiple usb ports and decent output wattage. Problem solved.
 
iOS16.5. Type of cable I used? NFI. Its a cable. With a lightning at one end, USB A at the other. It charges fine from just about every source, except on this plane. So then I used the battery I cart around everywhere.

I am totally disinterested in having to know what charges from where, using what make of cable etc. Stick one end into positive potential, the other end into negative potential and just carry some electrons between the two, FFS.
It’s not the cable but the usb socket. Older ones on some planes etc and hotel sockets have limited power. There are also various Apple charger packs that vary in output. Best to use a 25W than the older 5W ones, especially with iPads and later iPhones.
 

Enhance your AFF viewing experience!!

From just $6 we'll remove all advertisements so that you can enjoy a cleaner and uninterupted viewing experience.

And you'll be supporting us so that we can continue to provide this valuable resource :)


Sample AFF with no advertisements? More..
Back
Top