Posts by sokoloff

    In the US some dealers will print out a VMI (Vehicle Master Inquiry) for you. You might have to kiss up to get it, but I always try to get one. Not only does it give you all of the options on the car, but it also provides info about any work done at a Mercedes dealer.


    In a previous exchange we had, you told me to keep an eye on the "Measurement estimation" in my HV battery report. You weren't exactly sure what that meant, but said it should be around 0.80. I'd love to know more what that number means. Maybe this thread will bring an answer? Here is what I am talking about. These clips are snipped from my battery reports and are all from the same car.

    Prior to charging - car at 32%:

    Last measurement : 3 day(s)

    Measurement estimation: 0.805

    Actual estimation : 0.732

    CAP mean: 17392 As/10, 48.3 Ah

    CAP min : 17204 As/10, 47.8 Ah

    CAP max : 17541 As/10, 48.7 Ah

    Car fully charged:

    Last measurement : 0 day(s)

    Measurement estimation: 0.800

    Actual estimation : 0.800

    CAP mean: 17358 As/10, 48.2 Ah

    CAP min : 17191 As/10, 47.8 Ah

    CAP max : 17536 As/10, 48.7 Ah

    I'm at that 0.80 magic number, but what does it mean? I own three 451 EV's, so I'd be happy to provide more test data if it would help.


    And here are the numbers prior to charging the car overnight. State of charge was about 25%.

    Last measurement : 24 day(s)

    Measurement estimation: 0.819

    Actual estimation : 0.452

    CAP mean: 17354 As/10, 48.2 Ah

    CAP min : 17239 As/10, 47.9 Ah

    CAP max : 17570 As/10, 48.8 Ah


    While we are talking about this, I had one more 451 EV that I wanted to look at. So I ran the battery diagnostics on it and here is what I found.

    Test 6 months ago:

    Measurement estimation: 0.592

    Actual estimation : 0.462

    CAP mean: 16991 As/10, 47.2 Ah

    CAP min : 17045 As/10, 47.3 Ah

    CAP max : 17368 As/10, 48.2 Ah

    Test today:

    Measurement estimation: 0.805

    Actual estimation : 0.805

    CAP mean: 17392 As/10, 48.3 Ah

    CAP min : 17204 As/10, 47.8 Ah

    CAP max : 17541 As/10, 48.7 Ah

    I like the 0.805 number compared to the last one. Why the difference I have no idea. but I feel better about the condition of the HV battery now.


    Checked previous reports - battery measurement typically read 0.74 to 0.81. In fact the one in May of this year was 0.81. This car rotates use with one of my other 451 EV's. Each of them typically sits unused for three weeks while I exercise the other one. That other one showed 0.59 on its last test. My third 451 EV is routinely used and doesn't sit for periods like the other two do. It's last test a few days ago read at 0.80. Could the lack of use and down time be a factor I wonder?


    Thanks - you know there must be so much information on the HV battery read out that I have no idea what it means. This is the first time I ever paid any attention or even looked at "The measurement estimation number." So what exactly is that number telling me?


    Cable max 204 A? Never looked at that number before. My son built the unit and what cable it refers to I have no idea, but looks like every battery test shows the same thing.

    When you say " repeat the process if it's still below 0,8," what are you referring to as 0.8?


    Thanks for the reply. Interesting to note is that this car with the lowest Ah numbers has the best range of my three 451 EV's by about five miles on average. BTW the car is a 2014 and is not under any kind of warranty. But your 41.6 Ah number makes me feel a little better as does your info that the car will still drive even after it hits that number. :)

    Attached is that latest battery report.


    I'm a little concerned about the health of the HV battery in one of my 451's. I bought it new and I typically do a battery check every six months or so. The Ah number has gone down from 53.1 Ah in 2017 to 45.3 Ah now. I know that Mercedes considers the battery "toast" when it gets down to around 43 Ah or so. So do I have to worry or is there something I can do now to stop the decline? And also, once the Ah hits that magic number, what happens? Is the car still functional? As an FYI, the Ah's in my other two 451's have also gone down, but a bit less - they are in the 47 to 48 Ah range.


    I had no guarantee on my HV battery and I change the 12v battery after about six years, but I do check it every few months. IMO changing the 12v battery every three years is expensive overkill, but I guess if you sleep better at night, that's something to consider.


    2014 EV Coupe 22,500 miles

    2014 EV Cabriolet 24,000 miles

    2015 EV Coupe 22 000 miles

    In my case I've got three 451's and almost always charge them in my garage on a 110v outlet. I've had one of the cars for almost seven years and I have had no issues with the way I charge. I have replaced the 12v battery though. When the car gets below 40% is when I usually charge it, but if I know I'm going to need the car the next day and I'm even up around 60%, I have no problem putting it on the charger overnight and charging it up to 100%. And even when it is fully charged, I sometimes don't get out to the garage to unplug it for several hours after it is finished charging. Actually the car never really charges to 100%. The battery test tool I have indicates that the real state of charge is about 96% even though your gauge says it is at 100%. So for me this has been no problem and I haven't and don't plan to drive myself crazy worrying about my charging techniques.


    2014 EV Coupe 22,000 miles

    2014 EV Cabriolet 23,000 miles

    2015 EV Coupe 21,000 miles

    Thank you VERY much for this info. I want to make sure we are talking about the same part. As you can see in my third photo, i.e. the piece with the scrape mark and dimples on it, that's the piece that may need to be replaced. Looks like your instructions are about removing the lower valence piece. Maybe that needs to come off before removing the piece I'm talking about?

    My initial search for the part may indicate that it is not available. I need part number A451 647 00 01 CE6L, called a rear-end center section of the rear body panel. That part number did not come up, but it looks like Mercedes now sells a generic panel that needs to be painted. The original panel is molded plastic with the color all the way through.

    Thanks once again for your help and for this new forum.


    I had a minor fender bender the other day. I was in bumper to bumper traffic going no more than about 5 mph when the driver behind me hit me in the rear and pushed me into the car in front of me. There were no injuries and the damage looks to be very minor in all three cars. My 451 has a scrape mark and a couple of dimples, probably from the car's license plate that hit me. I looked closely for other damage around and under the car and saw none. However, in order to make things right, I may need to replace the rear bumper panel if it is even available. Do any of you have a good link to doing that?



    2014 EV Coupe

    2014 EV Cabriolet

    2015 EV Coupe - this is the one with the damage

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