Cigarette lighter question
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From: Long Island, New York
2018 E400 4matic Wagon
Cigarette lighter question
Currently, on my 2018 E400 wagon, the cigarette lighters/12 volt power outlets (on the passenger side of the transmission tunnel and the rear cargo area) turn off when the ignition is off. That means that you can't just plug in a battery maintainer -- you have to attach the battery maintainer to the charging post under the hood. On my W211 wagon, there was a certain fuse in the engine compartment where you could move the fuse to one side and it would make the 12 volt power outlets "live" all the time.
Is there such a fuse on a W213 and if so, which fuse is it?
Is there such a fuse on a W213 and if so, which fuse is it?
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2019 E 450, 2016 E350 4matic (retired), 2018 Ford Edge Sport, 2008 Porsche Boxster
Does the UBS port remain alive after the ignition is turned off or does that go dead as well?
Thanks.
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Thread Starter
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From: Long Island, New York
2018 E400 4matic Wagon
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.
I recall a previous discussion where there was a time delay between when the car was turned off and when the USB sockets lost power. IIRC the timeout was was about 10 minutes. As a test plug a light into a USB socket to make sure it doesn't turn off after some minutes.
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Thread Starter
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From: Long Island, New York
2018 E400 4matic Wagon
I just checked and the USB ports in the center console have continous power even when the ignition is off. This a great solution. Now I won't have to open the hood just to trickle charge the car.
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W214 E450
Don't you still have to open the door? You could easily have a traditional charge cable under the hood and routed to the front grille. Then you don't have open anything. Just plug it in.
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Here's the link:
https://www.amazon.com/dp/B0D3M6K9BS...lxgnl8YhU&th=1
https://www.amazon.com/dp/B0D3M6K9BS...lxgnl8YhU&th=1
Thread Starter
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From: Long Island, New York
2018 E400 4matic Wagon
"Don't you still have to open the door?"
No, actually you can just leave the trickle charger outside the car and close the door on the thin wire that goes from the charger to the USB port. On my Porsche 911 (where the cigarette lighter is live continuously) I've been doing this for years.
No, actually you can just leave the trickle charger outside the car and close the door on the thin wire that goes from the charger to the USB port. On my Porsche 911 (where the cigarette lighter is live continuously) I've been doing this for years.
Last edited by Long Islander; Dec 23, 2024 at 09:44 PM.
Thread Starter
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From: Long Island, New York
2018 E400 4matic Wagon
i don't think it's a good idea to use that adapter to plug in a battery tender to charge the car battery. Ideally, you should go with a direct connection to the battery. Yes, you can use a 12V auxiliary plug used for cigarette lighters but a USB port doesn't seem like it would work. USB is 5V while the battery and auxiliary port is 12V. The USB to auxiliary port converts from 5V to 12V. Not sure what will happen in reverse.
Thanks for your thoughts.
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2019 E 450, 2016 E350 4matic (retired), 2018 Ford Edge Sport, 2008 Porsche Boxster
"Don't you still have to open the door?"
No, actually you can just leave the trickle charger outside the car and close the door on the thin wire that goes from the charger to the USB port. On my Porsche 911 (where the cigarette lighter is live continuously) I've been doing this for years.
No, actually you can just leave the trickle charger outside the car and close the door on the thin wire that goes from the charger to the USB port. On my Porsche 911 (where the cigarette lighter is live continuously) I've been doing this for years.
Interesting points about the UBS being 5 volts and the trickle charger being 12 volts.
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I think you are right
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2018 E400 4matic Wagon
I did a test. After my car had been off for an hour or so, I plugged in my iPhone to the USB port next to the cupholders when the ignition was off and it charged my iPhone. I put the iPhone on the driver's seat and left the window open. After about 40 minutes, I reached in through the open window and the iPhone was still charging, meaning the USB port was still live. So the USB port next to the cupholders does not turn off after 10 minutes.
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I did a test. After my car had been off for an hour or so, I plugged in my iPhone to the USB port next to the cupholders when the ignition was off and it charged my iPhone. I put the iPhone on the driver's seat and left the window open. After about 40 minutes, I reached in through the open window and the iPhone was still charging, meaning the USB port was still live. So the USB port next to the cupholders does not turn off after 10 minutes.
Now the question is whether my CTEK trickle charger will work in the UBS slot: the question: 12 volts going through the UBS port.
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2018 E400 4matic Wagon
I called Deltran to see what they thought of using the USB port, but they were closed for Christmas eve. I'll call them on Dec. 26 and post their response.
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GLE 580
What if you lock the doors? Do the USB ports turn off after a set amount of time? They do on my v167.
I have a quick connect pigtail connected just underneath the plastic cover in the engine bay where there is a negative terminal and the positive post (with a red slide cover) for jumping the battery. I then place the pigtail nearby the wiper but tucked away just underneath the hood. I did this on my last vehicle and had no issues.
I have a quick connect pigtail connected just underneath the plastic cover in the engine bay where there is a negative terminal and the positive post (with a red slide cover) for jumping the battery. I then place the pigtail nearby the wiper but tucked away just underneath the hood. I did this on my last vehicle and had no issues.
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2019 E 450, 2016 E350 4matic (retired), 2018 Ford Edge Sport, 2008 Porsche Boxster
I just did a Google search and came up with the following:
No, a standard USB port alone cannot power a typical car battery trickle charger because the voltage output from a USB port is too low (usually 5 volts) compared to the 12 volts needed to charge a car battery; therefore, you would need a special adapter to use a USB port to power a trickle charger for a car battery.
Key points:
- Voltage mismatch:
A standard USB port only provides 5 volts, while a car battery requires 12 volts to charge properly. - Current limitations:
Even if you could somehow adapt the voltage, the current output of a standard USB port might not be high enough to effectively trickle charge a car battery.
There is no good way. The output of a USB port is a tiny fraction of the power needed to charge a car battery. A car battery might hold 80 Amp Hr at 12 V. A USB 2 port can provide 0.5 Amp at 5V. So it is going to take something like 500 hours to charge up that battery - call it three weeks, assuming no losses.
see: https://www.quora.com/Whats-the-best...attery-charger
Last edited by JTK44; Dec 24, 2024 at 11:55 AM.
Thread Starter
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Joined: May 2003
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From: Long Island, New York
2018 E400 4matic Wagon
What if you lock the doors? Do the USB ports turn off after a set amount of time? They do on my v167.
I have a quick connect pigtail connected just underneath the plastic cover in the engine bay where there is a negative terminal and the positive post (with a red slide cover) for jumping the battery. I then place the pigtail nearby the wiper but tucked away just underneath the hood. I did this on my last vehicle and had no issues.
I have a quick connect pigtail connected just underneath the plastic cover in the engine bay where there is a negative terminal and the positive post (with a red slide cover) for jumping the battery. I then place the pigtail nearby the wiper but tucked away just underneath the hood. I did this on my last vehicle and had no issues.
Regarding the quick connect suggestion, do you have to open the hood to access the quick connect? I did a similar thing in a Jaguar that I had where the battery was in the trunk. If I could easily access a positive post in the cargo area of my W213, I would do that. There's a fuse box on the right side of the cargo area behind a snap-out carpeted panel, but I didn't see a positive post to which I could attach a quick connect.
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From: Tennessee
W214 E450
I just did a Google search and came up with the following:
No, a standard USB port alone cannot power a typical car battery trickle charger because the voltage output from a USB port is too low (usually 5 volts) compared to the 12 volts needed to charge a car battery; therefore, you would need a special adapter to use a USB port to power a trickle charger for a car battery.
Key points:
No, a standard USB port alone cannot power a typical car battery trickle charger because the voltage output from a USB port is too low (usually 5 volts) compared to the 12 volts needed to charge a car battery; therefore, you would need a special adapter to use a USB port to power a trickle charger for a car battery.
Key points:
- Voltage mismatch:
A standard USB port only provides 5 volts, while a car battery requires 12 volts to charge properly. - Current limitations:
Even if you could somehow adapt the voltage, the current output of a standard USB port might not be high enough to effectively trickle charge a car battery.
In this direction
Home AC Power -> Trickle charger -> cigarette to USB converter -> car battery
Not in this direction
USB Port -> Trickle Charger -> battery
Three complications I see in this. One is the USB to Aux that converts 5V to 12V. The second is the car's internal electrical system converting the 12V to the 5V for the USB port. Lastly, there may be circuits in place to prevent doing this so it doesn't damage sensitive electrical circuits. I seriously doubt a USB port has a direct path from the battery like some auxiliary outlets may have. Ther are likely some additional electronics in between since it's not just a power port but also data to the entertainment system. All I can say, is that I would never even think about doing this. Then again, I never thought you could use the auxiliary ports (cigarette lighter) as a route to the battery so what do I know. For the auxiliary port, it makes more sense since it's 12V and just power. The USB port is a data port that only has 5V for power. Very different animal.
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GLE 580
In terms of locking the doors, I don't know the answer to that question, but it doesn't matter to me because I never lock my cars in the garage (and they're always garaged).
Regarding the quick connect suggestion, do you have to open the hood to access the quick connect? I did a similar thing in a Jaguar that I had where the battery was in the trunk. If I could easily access a positive post in the cargo area of my W213, I would do that. There's a fuse box on the right side of the cargo area behind a snap-out carpeted panel, but I didn't see a positive post to which I could attach a quick connect.
Regarding the quick connect suggestion, do you have to open the hood to access the quick connect? I did a similar thing in a Jaguar that I had where the battery was in the trunk. If I could easily access a positive post in the cargo area of my W213, I would do that. There's a fuse box on the right side of the cargo area behind a snap-out carpeted panel, but I didn't see a positive post to which I could attach a quick connect.
I'm traveling at the moment so I can't snap any photos for upload.
Last edited by wildta; Dec 24, 2024 at 12:14 PM.
