Can a USB cable draw power?

[Tomoya Okazaki13]

Kinda off topic but also kinda tech related. 
My motorcycle's battery got drained... I didnt use it for about 4 days. It's never happened before (even with me not using it for a long time). This is the first time it drained liked that.
I did forgot that I had a cable plugged in the USB port. Does a USB cable on its own draw power? I'm sure it doesnt draw that much but maybe its because I left it plugged on for months that it finally drained my battery lol

[Arika]

If it does, it would be so minuscule that it doesn’t matter.

[manikyath]

just a regular ordinary usb cable - no. it's copper.

 

there are cables that have little "there is power present" LED's in them, and there's even illuminated cables out there. those obvious draw an amount of power to (literally) keep the lights on.

[Tomoya Okazaki13]

thankyou for the answers ya'll
maybe its just a faulty battery, or something is draining the battery (probably the motorcycle's anti theft alarm)..
kinda wack the motorcycle doesnt have a voltmeter in it...

[TetraSky]

Most likely a faulty battery. If it's not powered on, the USB should not even get power in the first place. If it does, that's a horrible feature because anyone could just plug their phones on your motorcycle (depending on whether or not that port is accessible) .

[HenrySalayne]

9 hours ago, Tomoya Okazaki13 said:

Kinda off topic but also kinda tech related. 
My motorcycle's battery got drained... I didnt use it for about 4 days. It's never happened before (even with me not using it for a long time). This is the first time it drained liked that.
I did forgot that I had a cable plugged in the USB port. Does a USB cable on its own draw power? I'm sure it doesnt draw that much but maybe its because I left it plugged on for months that it finally drained my battery lol

In cars USB power supplies for the lighter socket do in fact drain power while idling. It's not much but it can add up. That's why on most cars the lighter socket is only turned on if the keys are turned.

For your particular case it could be possible that the USB socket has some form of switch/detection which will keep the USB power supply active as long as there's a cable inserted.

 

It's generally a good idea to either disconnect batteries for long term storage (> 2 month) and infrequent use or to use a trickle charger on the lead acid battery.

[Mark Kaine]

On 9/2/2023 at 1:02 PM, TetraSky said:

plug their phones on your motorcycle

ah, yes, my motorcycle....

[Mark Kaine]

On 9/2/2023 at 10:05 AM, Tomoya Okazaki13 said:

Kinda off topic

well yes, yes, it can, electricity doesn't really work how we learn it does in school (similar to airplane / wing lift btw) these are just more like metaphors than actual scientifically correct explanations (because its way too difficult to understand,  some things are simply not known how they work in their entirety, etc) but no, that's unlikely to be the case for your usb cable, although it might be a short / leakage somewhere, who knows. 

 

 

[Godlygamer23]

Cables do not draw power on their own, even if they're connected to a power source, unless some other electrical component is actually connected(i.e. capacitors, LEDs, etc). Even then, unless the USB port is powered from the battery even when the ignition is not on, there should be no energy loss. 

[Bitter]

It's possible that the USB power socket may have a sense on it that turns the whole socket on when a device is connected and that loss in addition to the normal losses (ecm memory) may have drained the battery. Do a parasitic draw test and see what the drain is with the USB cable plugged in and unplugged.

[wanderingfool2]

1 hour ago, Godlygamer23 said:

Cables do not draw power on their own, even if they're connected to a power source, unless some other electrical component is actually connected(i.e. capacitors, LEDs, etc). Even then, unless the USB port is powered from the battery even when the ignition is not on, there should be no energy loss. 

19 minutes ago, matewmaclaine said:

I agree, without a power consumption source there are no chances to drain battery.. 
But yes, if the battery is been used for several months and have faults or other issues 
Then it's common to get drained automatically

It depends, some "cables" actually do have some minor circuitry inside of them.  It's not just bare wires anymore.

 

If that's enough for the vehicle to detect something is plugged in, and if it has logic to keep the USB powered (lets say if it's the concept of a dashcam powered) then you could get battery drain.

 

I've learned never to underestimate the logic behind legacy auto; as they sometimes build in completely weird features that can do things like drain the 12 V battery.

 

To the OP; if lets say your USB port remains active when your vehicle is off; then there is a chance it could be the cause (Easiest way plug in a phone and see if it charges while it's off).  With that said it could still be triggering things even if it's not really providing power (auto manufactures sometimes do weird things).  But if you do plug it in and your phone powers up I would suspect maybe it is the USB (as then the 12V would have to be powering the whole USB circuitry)

[MG2R]

What motorcycle?

 

[mMontana]

On 9/2/2023 at 10:05 AM, Tomoya Okazaki13 said:

Does a USB cable on its own draw power?

Might. Sort of.

USB is 5v. Veichle battery usually is 12v.

If the USB plug is designed for switching on the dc-dc converter while a cable is plugged, might draw power to "kill" the battery.

 

However, maybe battery was not that good or there's other power drains somewere. Again.. might.

 

Never add a circuit to a vehicle outside the ignition switch if you're don't know how to do it... Because the battery would love a bit too much to be draine.

[djksm]

On 9/4/2023 at 3:05 AM, mMontana said:

Might. Sort of.

USB is 5v. Veichle battery usually is 12v.

If the USB plug is designed for switching on the dc-dc converter while a cable is plugged, might draw power to "kill" the battery.

 

However, maybe battery was not that good or there's other power drains somewere. Again.. might.

 

Never add a circuit to a vehicle outside the ignition switch if you're don't know how to do it... Because the battery would love a bit too much to be draine.

do you mean the battery would leave a bit too much to be drained?