USB PWR on/off

Stock4Evr · 05-09-2015, 05:16 AM

I believe the cigarette lighter is turned off when the car is turned off. On a 2012 135i does the USB also turn off when the car is turned off? I would not like a power drain when parked. I already had one problem with the battery and could not afford another. Comments welcome.

bmw1racer · 05-09-2015, 09:24 AM

Quote:

Originally Posted by SocHermit(2)

I believe the cigarette lighter is turned off when the car is turned off. On a 2012 135i does the USB also turn off when the car is turned off? I would not like a power drain when parked. I already had one problem with the battery and could not afford another. Comments welcome.

I'm pretty sure the USB is off when the car is off.... To be safe, I'd unplug whatever is plugged into it.

cmac49 · 05-09-2015, 01:42 PM

I've tested both the 12V cigarette lighter and 5V USB ports with a multimeter. With the ignition OFF, power to the 12V port is turned OFF while power to the 5V port remains ON (I.e. 5V USB port is always on).

With that said, I would think that USB power is eventually turned off after a period of time. I keep a USB drive plugged in 24/7 with my music collection and haven't had any issues yet.

Mac

rrinker · 05-09-2015, 07:05 PM

It does shut off. I left my phone in the car today (iPhone 5S, connected to the USB port under the armrest) and when I went to get back in the car, the phone buzzed and switched to charging as I put the key in. So it does shut off after some time delay.

--Randy

Stock4Evr · 05-10-2015, 07:58 AM

I am thinking that I recall reading that the radio stays on for approximately 20 minutes after the ignition is turned off. I would then think that power is supplied to the USB port for that 20 minute period. I guess I could try it and see what happens.

tracer bullet · 05-10-2015, 03:22 PM

Quote:

Originally Posted by SocHermit(2)

I guess I could try it and see what happens.

That's the safest thing to do. Probably easiest too. Maybe get something USB powered that has a light when it's receiving power, and see if / when it goes off.

Stock4Evr · 05-12-2015, 02:06 PM

Quote:

Originally Posted by tracer bullet

That's the safest thing to do. Probably easiest too. Maybe get something USB powered that has a light when it's receiving power, and see if / when it goes off.

My next opportunity I will test the 20 minute plan and post results.

05-09-2015, 05:16 AM	#1
Stock4Evr RetNavSpook 67 Rep 398 Posts Drives: 2012 135i - 2016 320i Join Date: Jan 2014 Location: Canyon Lake, Texas iTrader: (0)	USB PWR on/off I believe the cigarette lighter is turned off when the car is turned off. On a 2012 135i does the USB also turn off when the car is turned off? I would not like a power drain when parked. I already had one problem with the battery and could not afford another. Comments welcome.
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05-09-2015, 01:42 PM	#3
cmac49 New Member 0 Rep 12 Posts Drives: 2014 BMW M5 Competition Join Date: Apr 2015 Location: Dallas, TX iTrader: (1)	I've tested both the 12V cigarette lighter and 5V USB ports with a multimeter. With the ignition OFF, power to the 12V port is turned OFF while power to the 5V port remains ON (I.e. 5V USB port is always on). With that said, I would think that USB power is eventually turned off after a period of time. I keep a USB drive plugged in 24/7 with my music collection and haven't had any issues yet. Mac
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05-09-2015, 07:05 PM	#4
rrinker Enlisted Member 8 Rep 31 Posts Drives: 2012 135i M-Sport Join Date: May 2015 Location: Reading PA iTrader: (0)	It does shut off. I left my phone in the car today (iPhone 5S, connected to the USB port under the armrest) and when I went to get back in the car, the phone buzzed and switched to charging as I put the key in. So it does shut off after some time delay. --Randy
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05-10-2015, 07:58 AM	#5
Stock4Evr RetNavSpook 67 Rep 398 Posts Drives: 2012 135i - 2016 320i Join Date: Jan 2014 Location: Canyon Lake, Texas iTrader: (0)	I am thinking that I recall reading that the radio stays on for approximately 20 minutes after the ignition is turned off. I would then think that power is supplied to the USB port for that 20 minute period. I guess I could try it and see what happens.
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