[bateau]

I realize this subject has been beaten to death, but it appears that something may have changed in recent model years.

2013 328i can barely keep iPhone 6 charged when plugged in to center console.

2016 335i (7/2015 production) actually charges the phone with Waze and Spotify running. This seems to suggest that BMW started running more power through that port.

Does anyone (Technic??) know which part regulates the voltage in that USB socket? Is it the aux/usb socket itself or something further up the wiring harness?

[deviantspeed]

It's the same voltage. The amperage changed apparently. My 2013 puts out max .5 Amps. Most chargers today (including the one in my cig adapter) put out about 2.0 Amps. It fast charges my android very well.

But kudos on knowing the change, I'd like to know!

[bateau]

Right, current not voltage. Well I can confirm that 2013 328i with CIC is putting out 0.5A through center console USB.

The part # for AUX-IN/USB is the same between 2013 and 2016. I wonder if the difference is in the head unit. Will investigate further.

[Dan203]

0.5A is standard for USB. Some TVs will have 1.0A ports to run things like streaming sticks, but for the most part you'll only see higher then 0.5A ports on those wall wart chargers specifically designed to charge phones/tablets.

[Arthurrs]

What Dan203 said. I did a bit of research on my own, because my 2014 328ix only puts out 500 mA on the USB interface...

The internationally accepted USB *standard* is 500 mA. This is what the older NBT units provide.

Only in the recent past have we seen smartphones and other devices that can draw more current if the USB port supports higher current output. This is usually done on a manufacturer specific basis with some kind of custom pin identification procedure between devices to tell both sides of the USB interface that it is capable of supporting a higher current power capability. Apple has their own specific way of handling this, other manufacturers may do it differently. Bottom line is there is NO one common standard for supporting higher current USB interfaces and how devices communicate between each other to inform of that possibility. On hubs usually one USB port is dedicated for this purpose, same with some laptops and support is a mixed bag if you're not using the ever popular Apple products.

There is no way of modifying the USB interface on older NBT units to support these "newer" manufacturer high current features. The newer NBT units may support the higher current capabilities of certain smartphones, but alas I don't have one to check!

I will be testing out a way of using a high current capable USB hub with the USB interface from my NBT to see if this might be a potential workaround. I'm hoping to have some time to try this in the next week or so on my car. I need to dig out my soldering iron and develop a custom power adapter for it to work with the car's 12VDC power.

[bateau]

I bought a USB power meter and will check a 2016 model next time I'm at the dealership.
I wonder if a quick hack would be to get a spare usb socket (P/N 84109229247) and rewire the power pins to use a 2A 12V adapter. There's a 12V socket on the back of the center console. The data pins would go to the head unit.

[Arthurrs]

Originally Posted by bateau

I bought a USB power meter and will check a 2016 model next time I'm at the dealership.
I wonder if a quick hack would be to get a spare usb socket (P/N 84109229247) and rewire the power pins to use a 2A 12V adapter. There's a 12V socket on the back of the center console. The data pins would go to the head unit.

I don't think that would work. It's more than supplying power on the power pins, I believe that there's something in the data pins that indicates to the connected device that a higher current output is available.

[Dan203]

Originally Posted by Arthurrs

I will be testing out a way of using a high current capable USB hub with the USB interface from my NBT to see if this might be a potential workaround. I'm hoping to have some time to try this in the next week or so on my car. I need to dig out my soldering iron and develop a custom power adapter for it to work with the car's 12VDC power.

Hubs are powered, so you'd need to plug it into the lighter port. If you're going to do that you might as well just get a charger made for your phone that plugs into the lighter port directly.

If you also need USB to talk to the car there are splitter cables that separate the data portion of the USB from the power portion so you can charge from one port and talk to another. They're commonly used by USB hard drives to draw extra power from a second USB port while only communicating with one of them.

[Arthurrs]

Originally Posted by Dan203

Hubs are powered, so you'd need to plug it into the lighter port. If you're going to do that you might as well just get a charger made for your phone that plugs into the lighter port directly.

If you also need USB to talk to the car there are splitter cables that separate the data portion of the USB from the power portion so you can charge from one port and talk to another. They're commonly used by USB hard drives to draw extra power from a second USB port while only communicating with one of them.

Yep, got a special 12 VDC to 5 VDC 3A adapter from Amazon, and a small DLink USB hub that has a high current port, along with the appropriately sized connectors to go between.

I tried the USB splitter cable idea, didn't work for some reason, hence why I suspect there's something happening on the data pins to indicate that high current was desired.

Stay tuned....

[Fronzdan]

What might be a workaround for the low current problem, if such a thing exists or is possible, is a cable that splits off the power to a lighter adapter and passes the data through to the head unit. I'm thinking this might cause ground loops or something.

But indeed the 2014s and below have wimpy USB. When the phone is drawing too much current the USB port goes whacky. It'll connect/disconnect repeatedly and will often hose iDrive causing all USB devices to disconnect. You can actually replicate the problem by running a demanding app so the phone gets warm with power drain. Then plug it into the USB.

[gtthree]

I use one of these - it has two outputs

https://www.amazon.co.uk/Lighter-Pow.../dp/B0077PM3KG

Its made by scosche and can comfortably charge a tablet (nexus 7) and a phone (iphone 6)

Its very comapct and the ashtry lid can shut with the charger remainiing in the cigareete socket.

[matt@bavsound]

Some good info here. The basic deal is that with the 30-pin connector Apple used to use, you could charge via Firewire (9-12v DC) or USB (3.3-5v DC). Resistors in the charger or connection would tell the iPod or iPhone how much amperage was available and if Firewire or USB power was present.

Now, with the Lightning connector, there is a microprocessor in the connector itself that tells the iPhone what it's connected to, whether or not to charge, how much voltage and amperage are available, etc.

The allowed amperages for USB charging on the iPhone, iPad, iPod are 500mA (USB standard), 1000mA (Apple standard) and 2100mA (High Speed charging). Anything above that, the iPhone, iPod or iPad will ignore and regulate the charging amperage so that there are no issues with exploding batteries or things of that nature.

You could certainly try the trick you mentioned of connecting the data lines from the BMW connector to an extra USB port, and the power to an outboard adapter. The easiest thing to do would really be to pull the factory USB port and connect it to a M/F USB cable with only the power wires cut and rerouted to a nice 12V car charger that provides 2100mA. You could then install your new USB connector in the factory spot, and all should work perfectly.

It's also possible that the adapter from BMW itself is limiting amperage - they had a number of different iterations of the part during the transition away from Firewire charging to USB charging.

Let us know how it turns out!