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.
Len
Concerned about Ah decrease in HV battery
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I know that Mercedes considers the battery "toast" when it gets down to around 43 Ah or so.
At 80 %, which is 41,6 Ah, they would replace it for free, if it's still unter warranty.
once the Ah hits that magic number, what happens?
Nothing. As it did already, you loose range. But the car drives like before and would do so even if you only had 5 Ah left. Of course not as far anymore as when it was new (100 % battery health are considered to be at 52 Ah). When you got your smart, the battery had about 102 % health. Which is rather normal.
they are in the 47 to 48 Ah range.
Which is rather normal.
Feel free to post a full battery check, with all the cells and everything. So it's easier to say something about the battery.
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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.
Len
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Code
Alles anzeigenNovember 30, 2022 12v battery read 12.43 with multimeter Car was at 90% and not driven in the past few days. After about a 20 mile drive the battery read 12.7v. 12v battery read 12.4v OFF with test unit. Decrease in Ah numbers from the last test of about 3Ah ----------------------------------------- --- ED Battery Management Diagnostics --- --- v1.0.8 (451) --- ----------------------------------------- Connect to OBD port - Waiting for CAN-Bus .CONNECTED ----------------------------------------- ........Reading data....................O ----------------------------------------- Battery VIN: WMEEK9AA8EK786719 Time [hh:mm]: 17:46, ODO : 42221 km ----------------------------------------- HV Battery Status: OK Battery Production [Y/M/D]: 2014/3/6 Battery-FAT date [Y/M/D]: 2014/3/6 Rev.[Y/WK/PL] HW:2014/7/0, SW:2014/18/0 ----------------------------------------- SOC : 100.0 %, realSOC: 99.1 % HV : 388.5 V, -0.47 A, -0.18 kW LV :14.0V No LV health info because car is ON. ----------------------------------------- CV mean : 4178 mV, dV = 23 mV CV min : 4159 mV CVmax :4182mV OCVtimer: 1338 s ----------------------------------------- Last measurement : 0 day(s) Measurement estimation: 0.478 Actual estimation : 0.469 CAP mean: 16571 As/10, 46.0 Ah CAP min : 17041 As/10, 47.3 Ah CAP max : 17436 As/10, 48.4 Ah ----------------------------------------- HV contactor state ON, low current: 25 s Cycles left : 293560 of max. cycles: 300000 DC isolation : 52627 kOhm, OK ----------------------------------------- Temperatures Battery-Unit /degC: module 1: 26.0, 27.1, 27.5 module 2: 26.0, 27.5, 27.3 module 3: 25.9, 27.5, 28.7 mean : 27.0, min : 25.9, max : 28.6 coolant : 24.6 ----------------------------------------- # ;mV ;As/10 01;4179;16356 02;4179;16447 03;4180;16295 04;4179;16235 05;4181;16356 06;4181;16386 07;4178;16386 08;4178;16295 09;4179;16447 10;4182;16235 11;4182;16325 12;4179;16235 13;4179;16295 14;4177;16265 15;4174;16265 16;4178;16295 17;4180;16265 18;4178;16295 19;4179;16295 20;4178;16235 21;4179;16176 22;4175;16325 23;4181;16386 24;4179;16325 25;4180;16386 26;4180;16325 27;4181;16447 28;4181;16265 29;4178;16295 30;4182;16325 31;4181;16205 32;4179;16265 33;4158;16447 34;4179;16417 35;4180;16447 36;4182;16478 37;4173;16386 38;4182;16325 39;4179;16386 40;4183;16205 41;4182;16386 42;4177;16325 43;4179;16386 44;4181;16265 45;4181;16386 46;4178;16235 47;4176;16265 48;4177;16509 49;4178;16325 50;4178;16295 51;4177;16295 52;4175;16386 53;4178;16325 54;4182;16205 55;4178;16295 56;4179;16356 57;4177;16325 58;4179;16295 59;4175;16356 60;4176;16356 61;4179;16205 62;4178;16295 63;4176;16356 64;4177;16265 65;4174;16356 66;4175;16417 67;4179;16295 68;4181;16265 69;4180;16447 70;4177;16176 71;4179;16265 72;4177;16235 73;4178;16295 74;4177;16356 75;4181;16176 76;4179;16235 77;4179;16356 78;4180;16325 79;4177;16235 80;4177;16176 81;4177;16325 82;4179;16205 83;4179;16205 84;4177;16265 85;4179;16235 86;4179;16205 87;4179;16176 88;4180;16235 89;4178;16356 90;4177;16356 91;4178;16295 92;4180;16265 93;4177;16325 ----------------------------------------- Individual Cell Statistics: ----------------------------------------- CV mean : 4178 mV, dV= 25 mV, s= 2.92 mV CVmin :4158mV,#33 CVmax :4183mV,#40 ----------------------------------------- CAP mean: 16309 As/10, 45.3 Ah CAP min : 16176 As/10, 44.9 Ah, # 21 CAP max : 16509 As/10, 45.9 Ah, # 48 ----------------------------------------- Voltage Distribution (dV= 25 mV): *----------------------->-----[==|=]----* 4158 00 > [4177; 4179; 4180] < 00 4183 min [p25; median; p75] max ----------------------------------------- *** Experimental Data - NOT VERIFIED *** Maximum capacity @45C: 56.3 Ah Aging-Loss: 0.034 % Unknown counter: 0x110005 ----------------------------------------- Reading data....OK ----------------------------------------- Status OBL Charger-Unit: User selected : 16 A Cable maximum : 204 A AC L1: 0.0 V, 0.0 A DC HV: 0.0 V, 0.0 A DC LV: 14.1 V ----------------------------------------- emperatures Charger-Unit /degC: Reported : NA Cooling plate : NA Inlet socket : NA ----------------------------------------- Reading data.OK ----------------------------------------- Status Cooling- and Subsystems: Temperature : 29.1 degC Cooling fan : 0.0 % Cooling pump : 64.3 %, 30 degC : 13.6 V, 1.4 A OTR: Cooling fan : 1 h Cooling pump : 5422 h Battery heater: 0 h, OFF Vaccum pump : 22.379 h Pressure 1, 2 : -717 mbar, -717 mbar ----------------------------------------- * All measurements captured * ----------------------------------------- Battery VIN: WMEEK9AA8EK786719 Time [hh:mm]: 17:46, ODO : 42221 km ----------------------------------------- SOC : 100.0 %, realSOC: 99.1 % HV : 388.5 V, -0.47 A, -0.18 kW LV :14.0V No LV health info because car is ON. ----------------------------------------- ENTER command... (? for help) CMD >>
Out of curiosity: Why does it say the cable can do a maximum of 204 A?
What I'd do now:
drove the car to < 20 %, charge it up to 100 % and leave it plugged in for another 12 h or so. After that check the "Measurement estimation:" and repeat the process if it's still below 0,8. And check the values again, when the estimat is batter. Right now it's rather terrible, meaning rather imprecise measurements. So therefor the smart is going to say less Ah as it might actually has got. Which would also correspond with the good range you are getting.
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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?
Len
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When you say " repeat the process if it's still below 0,8," what are you referring to as 0.8?
The measurement estimation number.
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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?
Len
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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?
Len
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Maybe, we don't really know.
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Well I'm glad I asked. Thanks for the info and suggestions.
Len
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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.
Len
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State of charge was about 25%.
There it's more interesting what the voltage levels of the cells are.
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If you're interested, here is the report with the car at 25%.
Len
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Looking very good.
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