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I'm preparing to purchase an electric Smart soon, and I've procured one of the Sokoloff/Odyssey battery testers for the purpose of assessing used Fortwo examples. Some of the output is self-explanatory, but some of it is not.

Can anyone point me to where these values might be documented, or point out the important ones for determining the condition of a used Smart? Here is some example output I cribbed from another thread:

Code:
-----------------------------------------
--- ED Battery Management Diagnostics ---
--- v1.0.2                            ---
-----------------------------------------

Connect to OBD port - Waiting for CAN-Bus
.CONNECTED
-----------------------------------------
........Reading data....................OK
-----------------------------------------
Battery VIN: WMEEJ9AA3EK773721
Time [hh:mm]: 12:00,   ODO : 21255 km
-----------------------------------------
Battery Status   : OK

Battery Production [Y/M/D]: 2013/11/7
Battery-FAT date   [Y/M/D]: 2013/11/8
Rev.[Y/WK/PL] HW:2013/29/0, SW:2013/29/1
-----------------------------------------
SOC : 99.5 %, realSOC: 97.8 %
HV  : 389.0 V, -0.47 A, -0.18 kW
LV  : 14.2 V
-----------------------------------------
CV mean : 4163 mV, dV = 23 mV
CV min  : 4143 mV
CV max  : 4166 mV
OCVtimer: 1728 s
-----------------------------------------
Last measurement      : 4 day(s)
Measurement estimation: 0.795
Actual estimation     : 0.685
CAP mean: 17977 As/10, 49.9 Ah
CAP min : 17869 As/10, 49.6 Ah
CAP max : 18239 As/10, 50.7 Ah
-----------------------------------------
HV contactor state ON, low current: 216530 s
Cycles left   : 296198
of max. cycles: 300000
DC isolation  : 63931 kOhm, OK
-----------------------------------------
Temperatures Battery-Unit /degC:
module 1: 21.6, 23.0, 22.2
module 2: 21.7, 22.7, 22.4
module 3: 21.7, 22.5, 21.9
   mean : 22.2, min : 21.7, max : 23.0
coolant : 21.0
-----------------------------------------
# ;mV  ;As/10
01;4163;17632
02;4164;17576
03;4164;17745
04;4165;17604
05;4167;17632
06;4164;17632
07;4166;17632
08;4167;17632
09;4166;17660
10;4148;17548
11;4155;17604
12;4167;17576
13;4166;17548
14;4167;17576
15;4166;17548
16;4166;17604
17;4165;17660
18;4165;17717
19;4165;17660
20;4167;17689
21;4164;17576
22;4167;17689
23;4164;17576
24;4166;17717
25;4165;17717
26;4167;17604
27;4146;17520
28;4148;17492
29;4150;17520
30;4150;17576
31;4143;17492
32;4164;17604
33;4160;17576
34;4164;17548
35;4162;17576
36;4163;17604
37;4164;17604
38;4160;17492
39;4166;17492
40;4166;17465
41;4166;17465
42;4167;17520
43;4164;17548
44;4164;17548
45;4166;17492
46;4167;17492
47;4164;17520
48;4167;17576
49;4164;17576
50;4166;17548
51;4164;17576
52;4166;17410
53;4158;17437
54;4166;17548
55;4165;17548
56;4166;17604
57;4164;17492
58;4165;17604
59;4164;17632
60;4165;17548
61;4164;17604
62;4166;17604
63;4166;17548
64;4165;17660
65;4165;17604
66;4165;17548
67;4166;17548
68;4165;17660
69;4164;17604
70;4166;17604
71;4164;17492
72;4166;17548
73;4162;17576
74;4165;17660
75;4165;17548
76;4167;17520
77;4164;17548
78;4166;17548
79;4165;17717
80;4165;17660
81;4164;17660
82;4166;17660
83;4165;17660
84;4165;17604
85;4166;17520
86;4166;17492
87;4166;17548
88;4166;17520
89;4167;17548
90;4167;17492
91;4166;17548
92;4166;17660
93;4167;17576
-----------------------------------------
Individual Cell Statistics:
-----------------------------------------
CV mean : 4164 mV, dV= 24 mV, s= 4.73 mV
CV min  : 4143 mV, # 31
CV max  : 4167 mV, # 5
-----------------------------------------
CAP mean: 17579 As/10, 48.8 Ah
CAP min : 17410 As/10, 48.4 Ah, # 52
CAP max : 17745 As/10, 49.3 Ah, # 3
-----------------------------------------
Voltage Distribution (dV= 24 mV):
*----------------------------->----[|=]-*
4143   09 > [4164; 4165; 4166] < 00  4167
min         [p25; median; p75]        max
-----------------------------------------
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: 14.3 V
-----------------------------------------
Temperatures Charger-Unit /degC:
Reported       : NA
Cooling plate  : NA
Inlet socket   : NA
-----------------------------------------
Reading data.OK
-----------------------------------------
Status Cooling- and Subsystems:
Temperature   : 20.4 degC
Cooling fan   : 0.0 %
Cooling pump  : 64.7 %, 22 degC
              : 13.8 V, 1.4 A
OTR:
Cooling fan   : 5 h
Cooling pump  : 2946 h
Battery heater: 0 h, OFF
Vaccum pump   : 15.774 h
Pressure 1, 2 : -610 mbar, -604 mbar
-----------------------------------------


-----------------------------------------
Battery VIN: WMEEJ9AA3EK773721
Time [hh:mm]: 12:00,   ODO : 21255 km
-----------------------------------------
SOC : 99.5 %, realSOC: 97.8 %
HV  : 389.0 V, -0.47 A, -0.18 kW
LV  : 14.2 V
-----------------------------------------
 

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The cell capacities are close in value and close to max.

CAP mean: 17977 As/10, 49.9 Ah
CAP min : 17869 As/10, 49.6 Ah
CAP max : 18239 As/10, 50.7 Ah


Original capacity is about 52 Ah. So 50 is good.
 

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A few things. First, I thought the consensus was to use the lower set of capacity figures, which are as a result of the actual measurement rather than an estimation. In that case, the capacity would be:

CAP mean: 17579 As/10, 48.8 Ah
CAP min : 17410 As/10, 48.4 Ah, # 52
CAP max : 17745 As/10, 49.3 Ah, # 3

And that the actual capacity is based on the "CAP min", so 48.4 Ah versus 52.1, a loss of about 7% at the current time.

My experience is that the capacity can and will change depending on how the vehicle is used. If it is used sporadically and discharged over a few days, then recharged, the measured cell values gradually decrease. If you use a large percentage of the capacity in one shot, then recharge, the values increase. Also, if the battery has been sitting in a mostly discharged state for a long while, as this one appears to have been, the measured values will increase with some use. Temperatures also affect the cell values, with the maximum measurement seemingly occurring in the 60-70 degree F. range. (I say that it appears the battery has sat for a while because it looks like the measurement was taken while still being charged, and that the actual and displayed SOC are a bit below their max, which is what happens when we intermittently drive our ED, never fully discharging it in one shot).

There is a battery management upgrade that is available for this vehicle.

Otherwise, the battery stats look pretty decent. The individual cell values are all relatively consistent, with no one cell much lower than the others.
 

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I never quite understood what the capacity min, max and mean reported near the top of the printout really mean - and how or why they differ from the individual cell capacity min. max and mean reported further down the printout.

At any rate, to the original poster, the printout shown would be typical of a healthy pack that is a few years old and may have degraded a few percent. Another important things to look at is the individual cell statistics. The max and min voltages should not be more than a few tens of mv apart.

Her is mine from a 2015 used in a temperate climate and 29K miles:


-----------------------------------------
--- ED Battery Management Diagnostics ---
--- v1.0.5 ---
-----------------------------------------
-----------------------------------------
........Reading data....................OK
-----------------------------------------
Battery VIN: XXXXXXXX
Time [hh:mm]: 20:28, ODO : 46689 km
-----------------------------------------
Battery Status : OK

Battery Production [Y/M/D]: 2014/9/16
Battery-FAT date [Y/M/D]: 2014/9/16
Rev.[Y/WK/PL] HW:2014/7/0, SW:2014/18/0
-----------------------------------------
SOC : 84.0 %, realSOC: 82.7 %
HV : 371.6 V, -0.75 A, -0.28 kW
LV : 13.0 V
-----------------------------------------
CV mean : 3981 mV, dV = 30 mV
CV min : 3956 mV
CV max : 3986 mV
OCVtimer: 1254 s
-----------------------------------------
Last measurement : 0 day(s)
Measurement estimation: 0.758
Actual estimation : 0.751
CAP mean: 18864 As/10, 52.4 Ah
CAP min : 18038 As/10, 50.1 Ah
CAP max : 18398 As/10, 51.1 Ah
-----------------------------------------
HV contactor state ON, low current: 2 s
Cycles left : 291890
of max. cycles: 300000
DC isolation : 46332 kOhm, OK
-----------------------------------------
Temperatures Battery-Unit /degC:
module 1: 30.8, 32.1, 31.1
module 2: 30.8, 32.0, 31.2
module 3: 30.5, 31.9, 31.0
mean : 31.3, min : 30.5, max : 32.1
coolant : 29.3
-----------------------------------------
# ;mV ;As/10
01;3986;18630
02;3979;18364
03;3980;18439
04;3983;18439
05;3983;18553
06;3980;18515
07;3982;18591
08;3982;18477
09;3980;18477
10;3979;18364
11;3978;18439
12;3981;18591
13;3982;18630
14;3981;18553
15;3982;18630
16;3982;18553
17;3982;18591
18;3984;18591
19;3982;18515
20;3982;18477
21;3982;18553
22;3979;18364
23;3979;18364
24;3981;18439
25;3978;18402
26;3981;18439
27;3979;18439
28;3982;18477
29;3979;18439
30;3981;18402
31;3980;18364
32;3978;18364
33;3982;18477
34;3979;18364
35;3981;18439
36;3983;18515
37;3983;18477
38;3983;18439
39;3984;18668
40;3980;18364
41;3980;18402
42;3982;18439
43;3986;18630
44;3985;18630
45;3982;18477
46;3983;18402
47;3981;18477
48;3983;18439
49;3984;18477
50;3984;18477
51;3980;18402
52;3981;18327
53;3979;18364
54;3981;18327
55;3980;18402
56;3980;18290
57;3980;18439
58;3982;18439
59;3955;18327
60;3985;18364
61;3984;18327
62;3986;18402
63;3982;18477
64;3982;18477
65;3981;18439
66;3979;18364
67;3985;18553
68;3979;18515
69;3981;18553
70;3983;18477
71;3979;18477
72;3982;18515
73;3981;18439
74;3981;18402
75;3981;18515
76;3983;18439
77;3984;18477
78;3983;18439
79;3983;18515
80;3986;18439
81;3984;18439
82;3982;18327
83;3985;18477
84;3982;18553
85;3980;18477
86;3982;18402
87;3984;18477
88;3984;18515
89;3980;18477
90;3983;18477
91;3980;18402
92;3981;18364
93;3982;18515
-----------------------------------------
Individual Cell Statistics:
-----------------------------------------
CV mean : 3981 mV, dV= 31 mV, s= 3.37 mV
CV min : 3955 mV, # 59
CV max : 3986 mV, # 1
-----------------------------------------
CAP mean: 18461 As/10, 51.3 Ah
CAP min : 18290 As/10, 50.8 Ah, # 56
CAP max : 18668 As/10, 51.9 Ah, # 39
-----------------------------------------
Voltage Distribution (dV= 31 mV):
*-------------------------->----[=|=]---*
3955 00 > [3980; 3982; 3983] < 00 3986
min [p25; median; p75] max
-----------------------------------------
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: 13.9 V
-----------------------------------------
Temperatures Charger-Unit /degC:
Reported : NA
Cooling plate : NA
Inlet socket : NA
-----------------------------------------
Reading data.OK
-----------------------------------------
Status Cooling- and Subsystems:
Temperature : 29.0 degC
Cooling fan : 0.0 %
Cooling pump : 68.2 %, 30 degC
: 13.4 V, 1.8 A
OTR:
Cooling fan : 52 h
Cooling pump : 3610 h
Battery heater: 0 h, OFF
Vaccum pump : 46.722 h
Pressure 1, 2 : -469 mbar, -469 mbar
-----------------------------------------


-----------------------------------------
Battery VIN: WMEEJ9AA4FK830073
Time [hh:mm]: 20:28, ODO : 46689 km
-----------------------------------------
SOC : 84.0 %, realSOC: 82.7 %
HV : 371.6 V, -0.75 A, -0.28 kW
LV : 13.0 V
-----------------------------------------
 

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Yinzer, my understanding is that the values near the top of the report are estimations, while the values that are reported near the bottom of the report are calculated based on the individual cell statistics and therefore should be more indicative of the actual condition of the traction battery.
 

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Yes, the cell capacity estimates are easy enough to understand. The capacity estimation and that decimal value reported is a bit of a mystery. One would thing that someone in this forum could contact an MB engineer and have the report values explained. Fluency in German might help.
 
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