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1 battery, engine compartment no auxiliary battery. Confirmation of replacement in front SAM using Xentry (MB diagnostics), some do some don’t your call.
The 2018 E400 can have one of three different sized batteries, You need to physically measure it to be sure you are getting the correct one for your car. I just put the biggest one in, a group H8 (49) AGM as that is what they use in the E43. I think they all come with a 200A alternator so not sure what the differences are but probably the level of electronics in each version.
(Electronically) seamless process for replacing C238 and W213 batteries?
Do you have to do anything special to replace the battery (other than unscrew, remove and replace)? That is, do you lose settings or does anything need to be recoded? The OEM batteries in my 2019 E450 coupe and my wife's 2019 E300 sedan (both manufactured in late 2018) routinely read Partially Charged in the Mercedes Me Connect app. In fact, both have read Critical on multiple occasions and I've only seen (fully) Charged once or twice on either car in 12/17 months of ownership (both were CPO).
As a result, I assume it's time to replace both batteries and from a physical standpoint, would rather do it myself. Don't want to introduce any electronic gremlins, however, so any advice/personal experiences would be greatly appreciated!
Last edited by SidE2; 03-31-2023 at 08:59 AM.
Reason: Add title correct typos
Nothing special, easier to do with one person helping you to hold all the cables when you drop the new battery in the hole that it sits in. Other than that it is pretty much disconnect the old one and install the new one in reverse order.
2019 E450 Coupe 4Matic; 2018 Audi Q5; 2019 Toyota Corolla Hatchback
Originally Posted by SidE2
Do you have to do anything special to replace the battery (other than unscrew, remove and replace)? That is, do you lose settings or does anything need to be recoded? The OEM batteries in my 2019 E450 coupe and my wife's 2019 E300 sedan (both manufactured in late 2018) routinely read Partially Charged in the Mercedes Me Connect app. In fact, both have read Critical on multiple occasions and I've only seen (fully) Charged once or twice on either car in 12/17 months of ownership (both were CPO).
As a result, I assume it's time to replace both batteries and from a physical standpoint, would rather do it myself. Don't want to introduce any electronic gremlins, however, so any advice/personal experiences would be greatly appreciated!
When my car has not driven almost a week, the Me Connect app. showed the "Partially Charged" message as well. I connected the battery tender to the battery poles under the hood and charged the battery. Once it is fully charged, the Me Connect app. showed "Fully Charged".
I have the 2019 E450 as well and I am still having the OEM battery. The only concern is whether the battery needs to be registered. I think there are some OBD reader / scanner that you can purchase from Amazon and able to do the battery registration (not sure which brand and model).
PFL205.064 with M276.823 (Oil pump solenoid defeated)
Originally Posted by Ultraman
When my car has not driven almost a week, the Me Connect app. showed the "Partially Charged" message as well. I connected the battery tender to the battery poles under the hood and charged the battery. Once it is fully charged, the Me Connect app. showed "Fully Charged".
I have the 2019 E450 as well and I am still having the OEM battery. The only concern is whether the battery needs to be registered. I think there are some OBD reader / scanner that you can purchase from Amazon and able to do the battery registration (not sure which brand and model).
It is not a must procedure but it probably helps the vehicle learn about your new battery and therefore remove all the limitations (if there were any) that the vehicle put in place to prevent overstressing the battery.
2019 E450 Coupe 4Matic; 2018 Audi Q5; 2019 Toyota Corolla Hatchback
Originally Posted by W205C43PFL
It is not a must procedure but it probably helps the vehicle learn about your new battery and therefore remove all the limitations (if there were any) that the vehicle put in place to prevent overstressing the battery.
Having recently purchased a second hand C238, the car texted me "Critical battery level" whenever I sat in the car with something turned on. The "ME" app always reported back "Partially Charged".
With everything turned off the battery voltage was at 12.4V, sometimes 12.3. As a result of this, the boot never responded to keyless opening. Nor did the "ECO" drive activate.
After filing a warranty claim with the dealer, the battery was replaced. Now, ME always reports "Charged". Keyless boot works and (unfortunately) the ECO-drive as well.
The battery voltage is 13V with everything turned off. My opinion is that one cell was bad since the car always started w/o problem and the battery test returned 740A start
capacity (spec = 800A).
I had the dealer replace the battery. Otherwise, and that is if no Xentry interaction is involved, I always follow the procedure
below as recommended by a friend and long time mercedes mechanic:
1. Open the hood.
2. Take the driver side window down.
3. Turn off everything.
4. Lock the car
5. Remove any keyless key well away from the car.
6. Wait about 20 minutes for the car to go into sleep-mode.
7. Replace the battery.
By doing this, there will be no memory lost (window/panorama roof) etc.
If the system (temporary) looses any code sequence, it is always possible to open the door manually from the outside
and the car can be started using the transponder in the key.
PFL205.064 with M276.823 (Oil pump solenoid defeated)
Originally Posted by Uky
Having recently purchased a second hand C238, the car texted me "Critical battery level" whenever I sat in the car with something turned on. The "ME" app always reported back "Partially Charged".
With everything turned off the battery voltage was at 12.4V, sometimes 12.3. As a result of this, the boot never responded to keyless opening. Nor did the "ECO" drive activate.
After filing a warranty claim with the dealer, the battery was replaced. Now, ME always reports "Charged". Keyless boot works and (unfortunately) the ECO-drive as well.
The battery voltage is 13V with everything turned off. My opinion is that one cell was bad since the car always started w/o problem and the battery test returned 740A start
capacity (spec = 800A).
I had the dealer replace the battery. Otherwise, and that is if no Xentry interaction is involved, I always follow the procedure
below as recommended by a friend and long time mercedes mechanic:
1. Open the hood.
2. Take the driver side window down.
3. Turn off everything.
4. Lock the car
5. Remove any keyless key well away from the car.
6. Wait about 20 minutes for the car to go into sleep-mode.
7. Replace the battery.
By doing this, there will be no memory lost (window/panorama roof) etc.
If the system (temporary) looses any code sequence, it is always possible to open the door manually from the outside
and the car can be started using the transponder in the key.
PFL205.064 with M276.823 (Oil pump solenoid defeated)
Originally Posted by Ultraman
Agree.
To add to my post, it also has to do with the vehicle charging the old battery at a higher rate and higher voltage to help maintain the functions of the vehicle which obviously isn't needed on the new battery and might degrade the new battery faster because of that.
Well, just over a year after my last post on this topic, both my wife's E300 sedan and my E450 coupe started sending "battery critical" messages via email and occasionally "discharged" in Mercedes Me Connect. Because my wife doesn't drive her car as much as i drive mine, I visited my local Costco and handed over $169.99 for a size H7 AGM battery for her car.
For the two or three minutes it took for me to install her battery I connected our Noco Genius battery tender to her positive and negative terminals only to realize it wasn't providing power. Fortunately, once I replaced the battery, all settings - down to navigation memory and radio settings - remained intact. Because our cars were produced two weeks apart, I returned to Costco and bought my battery. This time I bypassed the Noco. Although my car was without power for about 20 minutes while I fiddled with a battery holddown nut that kept sliding out of position once again, everything worked per normal.
Definitely happy to see that the battery replacement process was "plug and play" for both cars.
Originally Posted by superpop
Nothing special, easier to do with one person helping you to hold all the cables when you drop the new battery in the hole that it sits in. Other than that it is pretty much disconnect the old one and install the new one in reverse order.
The 2018 E400 can have one of three different sized batteries, You need to physically measure it to be sure you are getting the correct one for your car. I just put the biggest one in, a group H8 (49) AGM as that is what they use in the E43. I think they all come with a 200A alternator so not sure what the differences are but probably the level of electronics in each version.
morning and sorry for the old thread resurrection!
would you happen to know where a 2018 E400 aux battery lives??? ours needs replaced and for the life of me and despite my best black belt search skills… I can’t find the location anywhere!
2019 E450 Coupe 4Matic; 2018 Audi Q5; 2019 Toyota Corolla Hatchback
Originally Posted by martin1977
morning and sorry for the old thread resurrection!
would you happen to know where a 2018 E400 aux battery lives??? ours needs replaced and for the life of me and despite my best black belt search skills… I can’t find the location anywhere!
I asked this question in the earlier thread. There was NO aux battery in the C238 (at least to my 2019).
01-16-2023, 02:27 PM
