12V battery change on 2017 E400
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Junior Member
Joined: Sep 2020
Posts: 25
Likes: 15
From: DC
2017 E400 wagon
12V battery change on 2017 E400
Main point: changing the battery is plug-and-play - no need to hook up a spare or a charger
I needed a new battery for our 2017 E400, and I planned to do it myself (have the battery shipped, save a little $ and a trip to the shop). I ordered the battery (upgraded to an H8 size for a few bucks more than the OEM H6) and did a quick Google search to make sure there was nothing weird about it, and I ran into a bunch of conflicting info on supplying power while changing it to avoid issues with computer settings. That stopped me in my tracks, and it took me about an hour of poring over forums and YouTube videos to be fairly confident that I could just pull the old one and drop in the new one. There are a few resources that suggest the 2017s still use an auxiliary battery and that you can run into problems if that battery's also bad; turns out Mercedes switched to capacitors for auxiliary power, so they'll power the car while you switch out the battery (assuming you're not getting a maintenance warning on the capacitors). I switched out the battery just like in an old pre-microprocessor car – zero problems with settings, anti-theft system, etc. Easy peasy.
I'm no maintenance authority – just adding one more data point to the "plug-and-play" line on changing the batteries in these cars.
I needed a new battery for our 2017 E400, and I planned to do it myself (have the battery shipped, save a little $ and a trip to the shop). I ordered the battery (upgraded to an H8 size for a few bucks more than the OEM H6) and did a quick Google search to make sure there was nothing weird about it, and I ran into a bunch of conflicting info on supplying power while changing it to avoid issues with computer settings. That stopped me in my tracks, and it took me about an hour of poring over forums and YouTube videos to be fairly confident that I could just pull the old one and drop in the new one. There are a few resources that suggest the 2017s still use an auxiliary battery and that you can run into problems if that battery's also bad; turns out Mercedes switched to capacitors for auxiliary power, so they'll power the car while you switch out the battery (assuming you're not getting a maintenance warning on the capacitors). I switched out the battery just like in an old pre-microprocessor car – zero problems with settings, anti-theft system, etc. Easy peasy.
I'm no maintenance authority – just adding one more data point to the "plug-and-play" line on changing the batteries in these cars.
Thread Starter
Junior Member
Joined: Sep 2020
Posts: 25
Likes: 15
From: DC
2017 E400 wagon
And, if you're curious: it hit me that the start-stop function hadn't been working for about a year. It was intermittent last fall and early winter and had been completely gone since spring. Most of our driving is a 10-minute, 3-mile round-trip drive to kiddos' school, so I realized the battery was probably never getting topped up by regular driving, and a trickle charger didn't help. It was the original, 5.5-year-old battery, so I figured I should probably swap it out to avoid any actual car-won't-start problems when it gets really cold this winter. 5.5 years ain't bad for a battery, and I'm planning to use a charger once a week to see how long I can make the new one last.
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Joined: May 2018
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From: Long Island, NY
2019 E 450, 2016 E350 4matic (retired), 2018 Ford Edge Sport, 2008 Porsche Boxster
And, if you're curious: it hit me that the start-stop function hadn't been working for about a year. It was intermittent last fall and early winter and had been completely gone since spring. Most of our driving is a 10-minute, 3-mile round-trip drive to kiddos' school, so I realized the battery was probably never getting topped up by regular driving, and a trickle charger didn't help. It was the original, 5.5-year-old battery, so I figured I should probably swap it out to avoid any actual car-won't-start problems when it gets really cold this winter. 5.5 years ain't bad for a battery, and I'm planning to use a charger once a week to see how long I can make the new one last.
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GLE 450e
Part of the reason of naming the 450e similar to the 450 is creating the perception that they perform similarly when it comes to acceleration and this is mostly true. It comes down to whether the sound of the 4 cylinder bothers you that much under hard acceleration. For the most part we won't be using the engine except on road trips.
