Originally Posted by Liam Rowe
Yea its not just me, I google it, and it seems to be a problem with many people who use AA and its not just Hyundai cars. thanks for your input though.
You can the issue. Indeed, people are reporting it, and use some solutions, like a "Y" cable suggested by kocyk123
, or a cable like .
However, I would be very cautious using a very high current chargers with it, - as they may damage the electronics (of the head unit or the phone), - see the explanation below.
However, I strongly suspect that your assessment of the problem might be incorrect: It is not that there is no charging from the USB port, rather, the current provided is low, compared to the consumption, and hence insufficient to charge the phone, or even to maintain the charge level.
I don't know if any of the newer Hyundai's have USB 3.0 ports, but my Sonata-2016 has what looks like a very standard USB 2.0 port.
The original specification for USB 2.0 was allowing no more than 500 mA (=0.5 A). [USB 3.0 allowed up to 900 mA (0.9 A)]
In 2010, "Battery Charging Specification" increased that limit to 1.5 A, but without concurrent
(The newer USB 3.1 with Type-C also allows 1.5 A and 3.0 A.)
The reason for this limit is to prevent from damaging the electronics responsible for data transmission. I've seen a few devices that will not do charging at the same time as they operate, but those were not phones or tablets, rather a speaker and a ear-piece.
There are chargers
that are providing up to 2.1A via USB ports, and some phones and tablets benefit from that higher charging rate. If you are using a Y-cable with such a charger, and are doing any communication via the other connector, I suspect, you might fry the electronics there.
I believe, the typical use for those cables is in the situation the "data-transmitting port" does not provide power at all or, possibly, when one connects it to two USB ports (0.5 A each).
I can see how some protection can be implemented by clearly separating "data" and "power" branches/connectors and not connecting "power" lines in the "data" connector. (That seems to be done in the cable I linked above on Amazon.) But even in that case, on the phone side you have all connected, and you might fry phone's electronics.
Some phones are capable of USB 3.0 (e.g. Samsung Galaxy S5). In that case, the electronics is by design must withstand up to 0.9 A while transmitting data. So, it is probably safe to connect it via the "discriminating" cable as discussed above to a charger that provides up to 1.0 A. (1.0 A is close enough to 0.9 A, so that risk is not that high.) But I would still be concerned about the head-unit's electronics if you are using a symmetric Y-cable.
Try it at your own risk!
I should point out that most phones, say, with a map app actively polling GPS and providing real-time navigation, usually consume more than 0.5 A. So, if your device is connected to a USB 2.0 port, charging and transmitting the data at the same time, its battery is effectively discharging (albeit slower compared to when not connected to the USB port at all). It varies with a phone, but with the phones that I observed, a typical current drawn while using GPS navigator with Google maps app (or Waze) is somewhere between 0.6 and 0.9 A. If you are running additional CPU-heavy apps at the same time (e.g. Video player, Pokemon Go, etc.), the current usage can get even higher and exceed 1A easily. (BTW, that leads to phone overheating.)