Question MP3 Player Battery will not Charge with Extended USB Cable

[Shervan360]

Hello,

I have one MP3 Player, when it connected directly to PC MP Player battery will charge, but if I used extended USB cable, MP3 player battery will not charge. (But I can work with MP3 player, e.g., read and write to it, seems the cable is fine)

What's the problem?

Thanks

 

[corkyg]

See if it will charge with a shorter cable. Also, what does the MP3 player's user guide say about charging? It would help to know the brand and model of the MP3 player.

 

[jasonlovesanandtech]

Hello,

I have one MP3 Player, when it connected directly to PC MP Player battery will charge, but if I used extended USB cable, MP3 player battery will not charge. (But I can work with MP3 player, e.g., read and write to it, seems the cable is fine)

What's the problem?

Thanks

USB cable has 4 pins: data + and -, power + and -. If extended usb cable data pins ok, maybe power pins not ok. One power pin maybe broken, maybe reversed.

You discover:
MP3 -> usb cable -> pc = ok
MP3 -> ext usb -> pc = no charge

Next, try test:
Another device -> ext usb -> pc = charge? y/n
if yes, problem is MP3, not ext usb cable
if no, problem is ext usb cable or pc

MP3 -> ext usb -> another pc or another USB port = charge? y/n
if yes, problem is pc or pc usb port
if no, problem is ext usb cable

This test will tell you if problem is MP3 device, ext usb cable, or PC/usb port

 

[HutchinsonJC]

How long is the extended cable? How good of a quality cable is it?

Some copper clad aluminum or other garbage materials for the cable might be a problem in a cheap cable over long distances.

You might be introducing too much voltage drop for the battery to charge in the device.

In serious car audio, I can tell you that you don't want a bunch of slack in your positive and ground leads to your amplifier because all that extra footage of cable beyond what's actually needed means voltage loss.

Ex: 14.4Volts across 2AWG aluminum wire for 10 feet with a 100 amp draw means a loss of 0.5 volts.

If you shorten the run down to 8 feet, you get back 0.2 volts.

If you change the aluminum 2AWG 10 foot run to a copper 2AWG 10 foot run you gain back almost 0.3 volts.

Distance & Quality of cable matters for voltage. Your device might not be getting enough voltage for the battery to charge with the extension cable either because it's low quality or the distance is too long or a combo of the two.

 

[mindless1]

One of the following may be true or a combination of issues. As HutchinsonJC mentioned, you could be losing fractions of a volt here and there and the cumulative resulting voltage is too low.


The extension cable power & ground conductors are too high a gauge (or it is poorly made) to support the current requirement of the MP3 player, so the voltage is dropping too low. Get a higher quality and/or shorter cable.

Some USB standalone chargers produce a voltage above 5.0V which might help too. You could also measure the voltage at the USB port to see if your PSU's 5VSB rail (if that's what is powering it) is struggling to keep up with the load, which is more common on questionable quality PSUs. If you have several things plugged into your USB ports you could try unplugging everything but the MP3 player.

 

[Paperdoc]

If, when using the extended USB cable, you cannot charge but can access data, my suspicion is that either the +5 VDC or the Ground lines has failed - bad wire in the cable, or bad connector contacts at either end. As jasonlovesanandtech has suggested above, testing by using other cables and / or USB sockets can focus in on the defective component.