When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I will be traveling abroad for a month, and my vehicle will not be in use during this time.
Is there any recommendations or definitions for energy savings to ensure that the battery does not get depleted while the vehicle remains unused?
Thanks
If you can park it in a secure location, put the car in standby-mode. I turns off many functions to save the battery. Unfortunately, the security/alarm system is turned off as well.
If you can park it in a secure location, put the car in standby-mode. I turns off many functions to save the battery. Unfortunately, the security/alarm system is turned off as well.
If your E-Class is a W214, there is no standby mode. I wouldn't worry about it sitting for a month, but you can put a battery tender on it. That's about all I would consider.
If your E-Class is a W214, there is no standby mode. I wouldn't worry about it sitting for a month, but you can put a battery tender on it. That's about all I would consider.
Not exactly. From the W214 Operator Manual
Go to Multimedia system:
Settings
Vehicle
Other Functions
Activate or deactivate Standby Mode.
I'm not sure what W214 manual you are seeing this in, but I have PDF versions of the 2024 and 2025 W214 and the word "standby" is not found in either manual. It does show up in the online manual for the W214 here, but the function does not exist in my car or the 2024 lease I had. In fact, there is no "Other Functions" sub-menu in the Vehicle settings. What is interesting with the online manual is that it says the car must be on but not running to put it in standby mode. I thought, maybe it's only there if I turn it on but not start it. I just tried and it's not there no mater what combination of on I put the car in. I believe only some engine models (maybe the e versions such as the 300e) have this or it's only available in some markets. The vehicle menu has sub-menus for Driving, Comfort, Occupant Protection, Open/Close and DYNAMIC SELECT. There is nothing below DYNAMIC SELECT and standby mode is not shown in any of the sub-menus that are there. If the OP is in the US, my bet is he doesn't have standby mode in his W214 either. I'm happy to be wrong though. It's possible that the W214 does an automatic standby mode after being parked for so long.
Edit: I did find "Standby" in the 2025 manual. For some reason it took a while to complete the search. Below is a copy of the page which is exactly the same as what the online manual states however, it doesn't exist in my car. Again, perhaps it's only on some versions or markets. Or I'm doing it wrong, but I've tried with car off, with one press on start, two presses on start, and car running. I don't see the menu option.
Last edited by L1Wolf; Sep 4, 2025 at 01:46 PM.
Reason: Added that I found Standby mentioned in 2025 pdf manual
Standby Mode is not available in all models for unknown reasons. I never figured out what the determining factor is. The only information that is there in the owner's manual is a disclaimer that it is not available on all models of the vehicle. It hasn't anything to do with hybrid or not hybrid or whatever. I have Standby Mode in my US spec 2019 C63S Coupe, so it's even present in AMG models. The option is just grayed out if the car isn't on. It has to be in ignition position 2 to activate Standby Mode.
If Standby Mode is available, that would be the way to go. It turns off the online services etc., so it doesn't slowly drain the battery. Modern, always connected cars are essentially like smartphones. They drain the battery in order to remain connected to the network and the battery drain is the highest if reception is weak and it has to boost the signal, so the Standby Mode is there to completely turn the car off when it's parked for an extended period. Almost the best part about Standby Mode is that it tells you how long you can go for without needing to charge the battery. With a full battery I get around 21 weeks.
I also have a month long trip coming up and I will put the car in Standby Mode as I always do. I check how long I have with the current state of charge, and if needed I go for a drive to charge the battery or hook it up to a battery charger before putting it in Standby Mode, so the charge is sufficient for how long I'll be gone.
Standby Mode is not available in all models for unknown reasons. I never figured out what the determining factor is. The only information that is there in the owner's manual is a disclaimer that it is not available on all models of the vehicle. It hasn't anything to do with hybrid or not hybrid or whatever. I have Standby Mode in my US spec 2019 C63S Coupe, so it's even present in AMG models. The option is just grayed out if the car isn't on. It has to be in ignition position 2 to activate Standby Mode.
If Standby Mode is available, that would be the way to go. It turns off the online services etc., so it doesn't slowly drain the battery. Modern, always connected cars are essentially like smartphones. They drain the battery in order to remain connected to the network and the battery drain is the highest if reception is weak and it has to boost the signal, so the Standby Mode is there to completely turn the car off when it's parked for an extended period. Almost the best part about Standby Mode is that it tells you how long you can go for without needing to charge the battery. With a full battery I get around 21 weeks.
I also have a month long trip coming up and I will put the car in Standby Mode as I always do. I check how long I have with the current state of charge, and if needed I go for a drive to charge the battery or hook it up to a battery charger before putting it in Standby Mode, so the charge is sufficient for how long I'll be gone.
I would like to know if any W214 owner has this. This topic has come up before and I haven't heard of a W214 owner saying they have standby mode.
2019 E 450, 2016 E350 4matic (retired), 2018 Ford Edge Sport, 2008 Porsche Boxster
Originally Posted by superswiss
Standby Mode is not available in all models for unknown reasons. I never figured out what the determining factor is. The only information that is there in the owner's manual is a disclaimer that it is not available on all models of the vehicle. It hasn't anything to do with hybrid or not hybrid or whatever. I have Standby Mode in my US spec 2019 C63S Coupe, so it's even present in AMG models. The option is just grayed out if the car isn't on. It has to be in ignition position 2 to activate Standby Mode.
If Standby Mode is available, that would be the way to go. It turns off the online services etc., so it doesn't slowly drain the battery. Modern, always connected cars are essentially like smartphones. They drain the battery in order to remain connected to the network and the battery drain is the highest if reception is weak and it has to boost the signal, so the Standby Mode is there to completely turn the car off when it's parked for an extended period. Almost the best part about Standby Mode is that it tells you how long you can go for without needing to charge the battery. With a full battery I get around 21 weeks.
I also have a month long trip coming up and I will put the car in Standby Mode as I always do. I check how long I have with the current state of charge, and if needed I go for a drive to charge the battery or hook it up to a battery charger before putting it in Standby Mode, so the charge is sufficient for how long I'll be gone.
I agree with everything except one small thing: My battery is the original in my 2019 E450. As per the build date the battery is 7 years old and entering its 8th year.
After I charge the battery when I go to standby mode, I get 37 weeks: if you are only getting 21 weeks, either the battery is not taking a full charge or it may be an indication that your battery needs to be replaced.
I agree with everything except one small thing: My battery is the original in my 2019 E450. As per the build date the battery is 7 years old and entering its 8th year.
After I charge the battery when I go to standby mode, I get 37 weeks: if you are only getting 21 weeks, either the battery is not taking a full charge or it may be an indication that your battery needs to be replaced.
Just my $.02!
A couple of points here. The 21 weeks is based on the original battery and I don't remember how many years into it. I have a new battery in the meantime, but haven't checked since then how many weeks it says. What I have noticed, though, is that with the new battery, I haven't seen the Mercedes app report that the battery is only partially charged even after not driving the car for a while. With the original battery, most of the time the app reported partial charge of the battery and I've even got critical battery alerts at times when the car was in for service and they had the doors open and such while working on it. It's very possible that I get more than 21 weeks now. I'll see when I put it in Standby Mode the next time.
However, the other point is that this calculation is based on preserving enough of a battery charge to crank over the engine a few times. The electric needs between models is different. For example my starter motor has to crank over 8 cylinders and displace 4l of air, while yours only has to crank 6 cylinders displacing 3l of air, but more importantly, your starter motor is powered by the 48V battery, not the 12V battery. The Standby Mode only preserves the 12V battery. In my car everything is powered by the 12V battery. I don't have a second 48V battery that powers the ISG to start the engine. Your 12V battery only powers the electronics. The more substantial consumers are powered by the 48V battery.
This may also explain why the W214 doesn't have standby mode anymore. They may have determined that it's no longer necessary in combination with the 48V system.
Last edited by superswiss; Sep 4, 2025 at 05:22 PM.
Does the standby mode measure voltage or is it doing a load test as well to determine battery health and time on standby?
7 to 8 years is a long time for a battery to last, but not unheard of. I've known people that got longer. That said, batteries don't often fail gradually. Most I've seen will die without much or any warning. I would never let my daughter drive on a 7 year old battery for fear it would leave her stranded one day. I will typically change a battery after 5 years even if it's not showing signs of failure. Although I've seen brand new batteries fail so you never know these days. Regular maintenance and checks are vital to staying off the side of the road. A car battery is one of the items that you should not follow the if it ain't broke, don't fix it mantra. Best to fix it before it breaks or it may break when it's not a good time for you.
Does the standby mode measure voltage or is it doing a load test as well to determine battery health and time on standby?
7 to 8 years is a long time for a battery to last, but not unheard of. I've known people that got longer. That said, batteries don't often fail gradually. Most I've seen will die without much or any warning. I would never let my daughter drive on a 7 year old battery for fear it would leave her stranded on day. I will typically change a battery after 5 years even if it's not showing signs of failure. Although I've seen brand new batteries fail so you never know these days. Regular maintenance and checks are vital to staying off the side of the road. A car battery is one of the items that you should not follow the if it ain't broke, don't fix it mantra. Best to fix it before it breaks or it may break when it's not a good time for you.
No, standby mode doesn't do a load test, but I'm guessing like any other battery management, it keeps track of charge cycles and other parameters that let it determine battery health and remaining capacity. Just like a smartphone tells you the health of the battery and remaining capacity in percentage. I'm not an expert on the exact algorithms behind this, but it doesn't involve load tests. Then knowing how much juice starting the car typically takes, it can determine what percentage of charge it needs to preserve plus enough headroom.
Age is not really a good measure for the health of a battery. Usage and charging patterns, number of charging cycles, how often it was discharged to a low percentage, temperature cycles and other environmental factors have a much larger impact on battery health.
Last edited by superswiss; Sep 4, 2025 at 05:52 PM.
2019 E 450, 2016 E350 4matic (retired), 2018 Ford Edge Sport, 2008 Porsche Boxster
Originally Posted by superswiss
A couple of points here. The 21 weeks is based on the original battery and I don't remember how many years into it. I have a new battery in the meantime, but haven't checked since then how many weeks it says. What I have noticed, though, is that with the new battery, I haven't seen the Mercedes app report that the battery is only partially charged even after not driving the car for a while. With the original battery, most of the time the app reported partial charge of the battery and I've even got critical battery alerts at times when the car was in for service and they had the doors open and such while working on it. It's very possible that I get more than 21 weeks now. I'll see when I put it in Standby Mode the next time.
However, the other point is that this calculation is based on preserving enough of a battery charge to crank over the engine a few times. The electric needs between models is different. For example my starter motor has to crank over 8 cylinders and displace 4l of air, while yours only has to crank 6 cylinders displacing 3l of air, but more importantly, your starter motor is powered by the 48V battery, not the 12V battery. The Standby Mode only preserves the 12V battery. In my car everything is powered by the 12V battery. I don't have a second 48V battery that powers the ISG to start the engine. Your 12V battery only powers the electronics. The more substantial consumers are powered by the 48V battery.
This may also explain why the W214 doesn't have standby mode anymore. They may have determined that it's no longer necessary in combination with the 48V system.
Actually, my model is a 2019 E450: it does not have the 48 volt battery.
2019 E 450, 2016 E350 4matic (retired), 2018 Ford Edge Sport, 2008 Porsche Boxster
Originally Posted by L1Wolf
Does the standby mode measure voltage or is it doing a load test as well to determine battery health and time on standby?
7 to 8 years is a long time for a battery to last, but not unheard of. I've known people that got longer. That said, batteries don't often fail gradually. Most I've seen will die without much or any warning. I would never let my daughter drive on a 7 year old battery for fear it would leave her stranded one day. I will typically change a battery after 5 years even if it's not showing signs of failure. Although I've seen brand new batteries fail so you never know these days. Regular maintenance and checks are vital to staying off the side of the road. A car battery is one of the items that you should not follow the if it ain't broke, don't fix it mantra. Best to fix it before it breaks or it may break when it's not a good time for you.
Since day one, I have charged my battery once in the fall before the winter season and once in the spring after the winter season. That regular maintenance helps the battery life.
Yes, an old battery, low on charge if hit with extreme low temperatures, might have a catastrophic failure. Other than that, my experience is not like yours: you see tell tale signs of the slow deterioration of the battery and I have no qualms letting my daughter drive my car. Having said that I intend to change the battery this fall before the winter season. No reason to "press my luck" and 7 years for a battery is excellent. I have certainly gotten my monies worth!
Actually, my model is a 2019 E450: it does not have the 48 volt battery.
Looks like Google let me down. I wasn't sure anymore, so I searched it. The basic point remains, though. There are differences between models as far as electric power consumption is concerned. Also depends on what optional equipment each one has, and I'm not even sure if the battery capacities are the same.
2019 E 450, 2016 E350 4matic (retired), 2018 Ford Edge Sport, 2008 Porsche Boxster
Originally Posted by superswiss
Looks like Google let me down. I wasn't sure anymore, so I searched it. The basic point remains, though. There are differences between models as far as electric power consumption is concerned. Also depends on what optional equipment each one has, and I'm not even sure if the battery capacities are the same.
On all W213 the standard battery is the H7. The holder can also accommodate the next size up battery the H8.
I will be traveling abroad for a month, and my vehicle will not be in use during this time.
Is there any recommendations or definitions for energy savings to ensure that the battery does not get depleted while the vehicle remains unused?
Thanks
I have been on travel for well over a month, and I never did anything special with either of my E450 wagons (2022 E450 All-Terrain or the 2025 E450 All-Terrain) that were parked in my garage. At the end of the trip, they started right back up, purring to life like well-fed Cheshire cats.
Looks like Google let me down. I wasn't sure anymore, so I searched it. The basic point remains, though. There are differences between models as far as electric power consumption is concerned. Also depends on what optional equipment each one has, and I'm not even sure if the battery capacities are the same.
Originally Posted by JTK44
On all W213 the standard battery is the H7. The holder can also accommodate the next size up battery the H8.
Hope this clarifies.
If it is the AI, I wouldn't be surprised.
Other than that, when it comes to the W214, the 48V started when MB switched to the M256 from the M276 on the facelift W213. On the four cylinder hand, in North America at least E 350 replaced E 300 just a model year or two prior to facelift M264 replacing M274.
I'm not sure what W214 manual you are seeing this in, but I have PDF versions of the 2024 and 2025 W214 and the word "standby" is not found in either manual. It does show up in the online manual for the W214 here, but the function does not exist in my car or the 2024 lease I had. In fact, there is no "Other Functions" sub-menu in the Vehicle settings. What is interesting with the online manual is that it says the car must be on but not running to put it in standby mode. I thought, maybe it's only there if I turn it on but not start it. I just tried and it's not there no mater what combination of on I put the car in. I believe only some engine models (maybe the e versions such as the 300e) have this or it's only available in some markets. The vehicle menu has sub-menus for Driving, Comfort, Occupant Protection, Open/Close and DYNAMIC SELECT. There is nothing below DYNAMIC SELECT and standby mode is not shown in any of the sub-menus that are there. If the OP is in the US, my bet is he doesn't have standby mode in his W214 either. I'm happy to be wrong though. It's possible that the W214 does an automatic standby mode after being parked for so long.
Edit: I did find "Standby" in the 2025 manual. For some reason it took a while to complete the search. Below is a copy of the page which is exactly the same as what the online manual states however, it doesn't exist in my car. Again, perhaps it's only on some versions or markets. Or I'm doing it wrong, but I've tried with car off, with one press on start, two presses on start, and car running. I don't see the menu option.
strange that my 2025 E450 doesn’t even have the car wash mode
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.
