My 2019 E-450 Wagon had a new AGM battery installed 2021, the year I bought it.
When parked in my garage for a week or more, I sometimes get a low voltage message, but easy to recharge and never tried to start it without plugging in first.
Seems like this is "normal" because all the electronics will drain the battery much more than an older car.

Monday next week I am driving 4 hours to the Fort Lauderdale airport for a trip to the old country and will be gone 7 days, or more if the flights are late.
I did order 16 feet, 6 gauge starter cables from Amazon and will back (reverse) into the parking spot for access to the hood in case I need a jump start.
Question: With a normal, healthy 2019 E-450 with a recent battery, what is the odds of the car NOT starting when I return from my trip.
(In other words, have any of you guys been stranded with a dead battery after 7-9 days at the airport? )

 

I've parked my '18 E300 at the airport for 17 days without any issues. That being said, make sure that you turn off the entertainment system as well as Keyless go. Use a quick double tap to turn it off. Otherwise, when a Bluetooth signal is nearby (think of people walking past your car) Keyless go will attempt to decode the signal and unlock the vehicle.

The specific instructions are probably in your Operator Guide, but mine isn't nearby to verify.

 

These stand-alone jumper units work so well, I would get one of these and store it in the truck. No jumper cables needed. I got one last Christmas, used it once, and it still has 85% of its first charge available.

GOOLOO GT3000 Jump Starter 3000A 100W 2-Way Fast Charging,

Amazon

Amazon

 

I remember reading somewhere in here we could put the car in sleep mode and use less energy. Not sure what the procedure is, maybe someone could chime in. I second the lithium ion battery portable jump starter, it work much better than I anticipated.

 

Good info, thanks.
I will look into how to turn off the Bluetooth and the entertainment, and the Keyless Go, etc.

 

Yes, that is standby mode, your battery has to have sufficient charge, what you do is you turn off your engine then tap the ignition button with foot off the brake, go to the vehicle settings menu in COMAND, scroll to the top and there is standby mode. https://cimg4.ibsrv.net/gimg/www.mbw...cdc89b9208.jpg

HOWEVER, I do not recommend this feature when parking at the airport as it disables the anti-theft alarm (to save power) and closes the communication between your car and the Mercedes Me servers (to save power) so you can't track it, remotely lock and unlock etc. I would only recommend those to enable it when they are going to the airport alone and leaving their vehicle at home in an enclosed garage.

 

Bluetooth is under connectivity under vehicle settings if I recalled correctly, also turn off wifi as well.
Keyless Go as already mentioned is just a double tap on the lock button on your key fob, do it for both keys as well but if you are bringing the key with you and the spare key is at home, there is no point turning it off as well, your vehicle is at the airport and you are enjoying your trip in a different location, your spare key is at home and your vehicle is at the airport. The key automatically goes asleep after a while when you are not moving it as well on the W213.

HOWEVER, perhaps you should disable the key that you are bringing with you just in case someone relay attack while you enter the airport. Better safe than sorry I suppose.

 

Wow, good info again, thanks.
No, I won't disable the anti-theft and the tracking programs.

 

I take 3 or 4 trips out west each winter to ski. Each time I leave my car for 8 days, outside at my friends house. Temps are down in the mid 20's. We take a cab to the airport.

When I return, I have never had a problem with my car starting.

My battery is the original: I got my car in December 2018 so the battery is 4 1/2 years old.

Hope this helps

 

Yes, it does help, thx

 

Mine’s a 2022 and hence not exactly the same as yours, due to the 48V additional battery. But I have left my car parked in a cold garage, for over 22+ days, in the middle of the OH winter, with nothing other than locking the car up with the remote, prior to the trip.

There was not even a whisper of a hiccup when I started it back up, on my return. Never even thought about a jump start etc and not sure why it would be otherwise.

 

good info, thank you.

 

Thanks, and good for you,
Unfortunately my car drops voltage at something like 0.10 volt a day. (I did measure the voltage with a digital voltmeter a few times, starting at 13.0 volts it would drop to 12.3 volts over 8 or 9 days.
Called my MB Service Advisor who said it is "Normal" but to leave it locked always.
This will be my first airport parking of more than an overnight as I have used rental cars in the past for longer trips.
Hoping I won't need the jumper cables, but they will be there just in case..


Good to know, thanks.

 

You're welcome, yup better to leave those features on especially since your car will be exposed to the public.

 

You're welcome. Honestly the major battery drain on modern MBs is really the communication and pinging between Mercedes Me servers ever once in a while.

 

Original battery? Good for you, do you do short commutes or long commutes to have a battery still healthy like this? Thanks. For example how does a typical car usage like?

 

You're welcome.

 

I'd say there's something wrong with your car if you can only leave it parked for 7 days before you get a low battery warning. That's not normal, unless you are driving very little. Not the same car, but for reference I had my C63 sit in my garage for several weeks during the pandemic with no issues. As mentioned above, the standby mode allows for extended parking, but yes that's not something you wanna use in public. Just to give you an idea, though. With a fully charged battery, standby mode gives me like 21 weeks before the battery runs low. Let's say not using standby mode cuts it in half then it's still something like 10 weeks.

 

I agree, there is something wrong. Do you have any aftermarket products installed that might be causing your parasitic battery drain? There are some shady dealers who like to tack on aftermarket products, like LoJack, and charge customers, so make sure something like that isn't installed.

 

I hope nothing is wrong with the car, it had a recent B service at the MB dealer, no fault codes, no nothing.
It was probably more than 7 days before I got the initial low voltage warning, don't remember exactly, possibly up to 2 weeks.
Since then I purchased a 1 amp battery maintainer I plug in if the car isn't used for 4-5 days, therefore I never had a problem, but
again, this will be the first time I leave at an airport for more than a few days.
Been using a car service but tired of paying $125 plus tip each way from Palm Coast to JAX airport (80 miles)
This time I am flying out of FLL airport, no car service available as it is 260 miles, been using rental cars for the FLL trips instead,
but i would rather use my own nice car in the future, hence the starter cables and this thread.
(I don't drive much when home, maybe that was the problem before I bought the battery maintainer, 3-4 miles a day may not be enough
to keep the battery healthy with AC at full blast)

 

Nah, the car has no aftermarket stuff, except a dash cam but is shuts off shortly after I park the car, but maybe I should un-plug it just in case..

 

Agree OP's car has a parasitic drain, no doubt. The SA's comment is typical BS.

Once your are back take it to a serious independent MB specialist to find the drain. In the meantime, just a guess, remove the push-start button for a few days and see if it goes away. Sister's W166 used to randomly drain the battery in a few days, even driving it. I read somewhere that KeylessGo module could go wrong and stays awake even if computer went to sleep. We tried removing it, and it has not drained the battery in 3 years now and same driving habits. She does not care about the push-start, so it is still w/o it.

Enjoy your trip, worry later

 

No that's not enough. that's actually not good for the car at all. You rarely get the engine truly up to operating temperatures. If you only drive this little, then you basically slowly drain the battery. 3-4 miles is not enough to replenish the energy used by the starter motor. Other issues you'll get over time is fuel contamination in the oil and carbon build up in the engine if you rarely get the engine nice and hot for an extended period. For only 3-4 miles I ride my bicycle. Not worth taking out the car.

 

That got me curious, I assume Italian tune-up doesn't work for direct injected engines? If so what can we do with the carbon, do you recommend injector cleaners and/or intake cleaning? What else do you recommend.

 

Italian tune up technically still works. The carbon starts burning off above a certain temperature, but it's kinda hard to reach and sustain those temperatures. Regular redlines, though, blow the engine threw properly and some of the gunk out. I don't know if they do it in all engines, but MB/AMG use oil separators to remove the oil from the intake charge that causes the carbon deposits. I haven't really heard of MB engines having a big carbon deposit problem at least today's engines. Ultimately, if you have carbon deposits only manual labor such as walnut blasting will remove it. BMW from what I recall did it as part of their scheduled maintenance. Not sure if it's still necessary with their latest engines. I had a carbon clean done on my Audi RS5. Audi's engines were notorious for carbon deposits and Audi didn't do much about it. Had it done at 60k miles and it wasn't too bad, but I did drive the car hard. I did notice a performance improvement afterwards, though.