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Pardon my ignorance but why the need for a battery maintainer? My 2018 e400 often sits for weeks at a time and always starts quickly.
In my experience, it only takes one or two instances of returning home from a trip to a dead battery to become quite frustrated with the situation. This happened with my previous car due to an aftermarket device that added Android Auto and CarPlay to the original head unit and created an electrical gremlin. I don't have this issue with my GLE but I've developed the habit of attaching the maintainer onto the car whenever I travel for four days or more--with the hardwired pigtail it only takes 30 seconds. While I sometimes travel for as long as 12 weeks, people say this practice helps prolong the life of the 12V battery, even during shorter trips.
Porsche Cayman S, Mercedes W213, Nissan Titan, BMW X5, Chevrolet Suburban
Originally Posted by JTK44
In my Porsche I used a CTEK trickle charger through the cigarette lighter: Both the trickle charger and cigarette lighter were 12 volts. It worked perfectly in maintaining a full charge on the battery.
The cigarette lighter is not directly connected to the battery: That did not hinder it from working. I think the same for the USB port.
I see no reason why the USB port would not work the same: the problem is that at 5 volts, the charge going through it, unlike the cigarette lighter is limited. As the Quora article points out, with only 5 volts and 1 or 2 amps of power in the trickle charger, it will work but may take very, very long.
On the other hand, if the batter is nearly fully charged, then maintaining the charge through the USB port should be doable.
I also use a CTEK trickle charger in the cigarette port in my Porsche. I went through 2 batteries before getting the trickle charger. I lower the window slightly so that I can close the door. The back seat of my e-class has a cigarette port and perhaps that could work for the OP.
Pardon my ignorance but why the need for a battery maintainer? My 2018 e400 often sits for weeks at a time and always starts quickly.
Some let their car or motorcycle sit for months at a time during winter. This can be an issue for batteries since they don't go through regular charge cycles. A few weeks won't be an issue but doing that repeatedly can reduce the life of the battery. A battery will last longer if it's charged and discharged in cycles. Discharging to zero or even near zero is very bad for a battery. It can be recovered, but at the expense of some usable life. Keeping it at 100% all the time is also bad. A battery tender will let the battery drain and then slowly charge it up over and over. This simulates regular usage and prolongs the life of the battery. I use one on my motorcycle but not my cars unless they will be sitting for a few weeks or more.
I also use a CTEK trickle charger in the cigarette port in my Porsche. I went through 2 batteries before getting the trickle charger. I lower the window slightly so that I can close the door. The back seat of my e-class has a cigarette port and perhaps that could work for the OP.
I tried that one but it also turns off with the ignition. On my 911, the cigarette lighter is continuously live and I plug in the Porsche-branded battery maintainer. I last got an AGM battery over 12 years ago and it's still good.
The solution to the issue of where to plug a battery maintainer is not to plug it in at all but to keep the battery from draining when the car is not being used by putting it in "standby" mode. See post in the following thread: https://mbworld.org/forums/e-class-w...tery-dies.html
The solution to the issue of where to plug a battery maintainer is not to plug it in at all but to keep the battery from draining when the car is not being used by putting it in "standby" mode. See post in the following thread: https://mbworld.org/forums/e-class-w...tery-dies.html
It would be nice if MB kept this feature in the newer models.
2019 E 450, 2016 E350 4matic (retired), 2018 Ford Edge Sport, 2008 Porsche Boxster
Originally Posted by Long Islander
The solution to the issue of where to plug a battery maintainer is not to plug it in at all but to keep the battery from draining when the car is not being used by putting it in "standby" mode. See post in the following thread: https://mbworld.org/forums/e-class-w...tery-dies.html
Sounds good up to a point: If you are leaving it at an airport, by putting in standby mode, all functions including the alarm are turned off.
So for extended periods in a secure place standby works. All others, not so sure, why a battery tender makes more sense.
For 20 years I used to fly 4 days a week throughout the US and Europe. Every mid-size and larger airport I visited had a secure long term lot shown on their facility map.
2019 AMG S 65 and too many other vehicles to list here in this small box
I know this is an old thread but there are 3 pages of 60 post now about this issue and I felt the need to add a final note on this discussion for safety sake.
Please, please, please do not ever even attempt to charge your car battery using any of the USB ports no matter what type of adapter or charger you might have. Just DON'T do it or your going to cause damage at some level. It might get to the point of starting a fire and then...
Not sure why people are afraid to open the hood and connect a charger the preferred way that MB shows in the owners manual. But it seems they are and want to just plug into a cigarette lighter receptacle to connect their charger. This is an alternative and acceptable method (as shown by MB) but there is one requirement that is overlooked by many who have found out the hard way. Not all cigarette lighter receptacles are the same. Some are rated for a higher current value and are designed to hand a larger load and likewise also able to handle a larger charging current your battery and charger decided you need. You need to do a little reading to see what the maximum value your outlets are rated for. Not all cars are the same so the owners manual is the best place to start and the fuse size for each outlet is also a good indicator of maximum amperage allowed.
Cigarette lighter receptacles that have a label indicating they are rated to handle 15 Amps is appropriate for charging the car battery. Many battery chargers are capable of producing a solid 10 amperes of current and the typical cigarette lighter receptacle can't handle that size load for an extended period without problems. Having a rating of 15 Amps will allow enough headroom to accommodate a full 10 ampere charge load without problems for an extended amount of time.
Here are a few items to note in the owners manual for connecting a battery charger:
Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren
Slideshow: A one-of-one U.S.-spec Mercedes-Benz SLR McLaren Roadster became even rarer after a factory-backed transformation at McLaren's headquarters.
