How to interepret "Lowest Brick" readings in Graphical Log Parser?

[wiztecy]

I downloaded Doug's graphical log parser below which is fantastic:
TeslaFlux

Here's the archived thread where I stumbled across the lowest brick feature:
Ideal range gradually dropping off [Archive] - Tesla Motors Club - Enthusiasts & Owners Forum

Lots of good information to take better care of your roadster and battery life. Cool seeing your driving and charging habits graphed so you can get a clearer picture on things.

There's one feature I'm trying to understand on reading the data which I find very useful, its the "Lowest Brick" output. It appears to be a series of numbers that read from left to right light a paragraph. From what I read you want these numbers to randomly change and I believe not continue for all that long. I also believe you don't want the same number that repeats across the line to keep repeating daily or not being random anymore.

My question is does anyone know how to officially read and interpret this data? I see 2 or even 3 sets of numbers the continue for a few lines. This was on a single day sample. But I can see those same numbers repeat earlier. I have logs back from when the car was built to now so I can compare how the pack's health was back then.

If possible can someone who has knowledge on this please explain how I should be using this data and feature? I do find it useful if I know how to properly read it. I think its purpose is to find a bad brick that has a cell going bad which can't sustain the voltage of the other cells hence pulling down the other cells to the weakest cell's voltage. Thanks!

 

[Doug_G]

If you see the same brick stuck as low brick permanently, then there could be a problem with it.

If you see the same brick low for a week or two but then another one replaces it, then it was probably just out of balance.

 

[wiztecy]

Thanks Doug for clarifying, very useful information. I'll analyze it. Is there any way to dump/parse the "lowest brick" history for an "x" number of days? I can write a script or use excel to do the analysis and determine if there's a pattern to identify a possible failing brick.

- - - Updated - - -

Looks like I'm seeing the same numbers repeating on long mutliple lines for many consecutive days. What caught my eye was that I was getting 189 ideal miles in range mode for a couple of months then it just dove down to 184 and now its at 182. When I'm done the charge its at 192 ideal miles and then when the battery pack begins to settle, within the first 3-5 mins of the charge completing it will just dive down to 183, then to 182 ideal miles.

I guess a bleed test is the next step. I have my last warranty period coming up in April. I don't know if I should wait til then or have the bleed test conducted now.... any thoughts?

 

[Doug_G]

I get long stretches of the same brick too, but it eventually balances out and another brick takes over. I wouldn't be concerned unless it was stuck for a very long time.

 

[wiztecy]

What would a very long time be? three weeks, one month, two months?

I want to keep an eye on it but address it if need be... especially before the warranty runs out. Hate to have any work like that happen a day or month after.

Some battery engineers are going to analyze my logs, I'll see what they have to say with the lowest brick and equalization of the pack.

 

[Doug_G]

Two weeks is probably not an issue; two months is a lot.

 

[wiztecy]

Two months back, same numbers

 

[Doug_G]

Just for reference, here's my most recent log:

67, 67, 67, 67, 67, 67, 67, 67, 67, 67, 67, 67, 67, 67, 67, 67, 67, 67, 67, 67
67, 67, 67, 67, 67, 67, 67, 67, 67, 67, 67, 03, 03, 03, 03, 03, 03, 54, 54, 18
18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18
18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18
18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18
18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18
18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18
18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18
18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18
18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18
18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 09, 09
09, 09, 09, 09, 09, 54, 54, 54, 54, 54, 54, 54, 54, 54, 54, 54, 54, 54, 54, 54
54, 54, 54, 54, 54, 54, 54, 54, 54, 54, 54, 54, 54, 54, 54, 54, 54, 54, 54, 54
54, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 54, 54, 54, 54, 54, 09
09, 09, 09, 09, 09, 09, 09, 09, 09, 09, 09, 09, 09, 09, 09, 09, 09, 09, 09, 09
09, 09, 09, 09, 09, 09, 09, 09, 09, 09, 09, 09, 09, 09, 09, 09, 09, 09, 27, 27
27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27
27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27
27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27
27, 27, 27, 27, 35, 35, 35, 35, 85, 85, 85, 85, 85, 90, 90, 90, 90, 90, 90, 90
90, 90, 90, 90, 90, 90, 90, 90, 90, 90, 90, 35, 35, 35, 35, 35, 90, 85, 85, 85
85, 85, 85

There are a lot of 18's, but it did eventually move on.

 

[wiztecy]

Here's my clip from a couple of days ago, 9-11-12:

26, 26, 26, 26, 26, 15, 15, 15, 15, 15, 03, 03, 08, 08, 03, 03, 03, 03, 03, 85
85, 85, 85, 85, 85, 85, 85, 88, 12, 14, 33, 14, 14, 14, 14, 14, 14, 14, 14, 14
14, 14, 14, 14, 14, 14, 14, 98, 98, 98, 98, 98, 98, 98, 70, 70, 70, 70, 59, 59
59, 19, 19, 19, 19, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00
00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00
13, 13, 44, 44, 44, 44, 44, 44, 44, 44, 44, 44, 44, 44, 44, 44, 44, 44, 44, 44
44, 44, 44, 44, 44, 44, 44, 44, 44, 44, 44, 44, 44, 44, 44, 44, 44, 44, 44, 44
44, 44, 44, 44, 44, 44, 44, 44, 44, 44, 44, 44, 44, 44, 44, 44, 44, 44, 44, 44
44, 44, 44, 44, 44, 44, 44, 44, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19
19, 19, 19, 19, 19, 19, 27, 05, 05, 05, 05, 05, 05, 33, 33, 33, 33, 33, 33, 33
33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33
33, 33, 33, 33, 33, 33, 33, 01, 01, 01, 01, 01, 01, 01, 01, 01, 01, 01, 01, 01
01, 01, 01, 01, 01, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22
22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22
22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22
22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22
22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22
22, 22, 22, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92
92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92
92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92
92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92
92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92
92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92
92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92
92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92
92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92
92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92
92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92
92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92
92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92
92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92
92, 92, 92, 92, 92, 92, 92, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31
31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31
31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31
31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31
31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31
31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31
31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31
31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31
31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31
31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31
31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31
31, 31, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33
33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33
33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33
33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33
33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 09, 09, 09, 09
09, 09, 09, 09, 09, 09, 09, 09, 09, 09, 09, 09, 09, 09, 09, 09, 09, 09, 09, 09
09, 09, 09, 09, 09, 09, 09, 09, 09, 09, 09, 09, 09, 09, 09, 09, 09, 09, 09, 09
09, 09, 09, 09, 09, 09, 09, 09, 09, 09, 09, 09, 09, 09, 09, 09, 09, 09, 09, 09
09, 09, 09, 09, 09, 09, 09, 09, 09, 09, 09, 09, 09, 09, 09, 09, 30, 30, 30, 30
30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30
30, 30, 30, 30, 30, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31
31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31
31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31
31, 31, 34, 31, 31, 31, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34
34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34
34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34
34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34
34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34
34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34
34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34



Here's the 7-25-12 sample:

26, 26, 26, 26, 26, 15, 15, 15, 15, 15, 03, 03, 08, 08, 03, 03, 03, 03, 03, 85
85, 85, 85, 85, 85, 85, 85, 88, 12, 14, 33, 14, 14, 14, 14, 14, 14, 14, 14, 14
14, 14, 14, 14, 14, 14, 14, 98, 98, 98, 98, 98, 98, 98, 70, 70, 70, 70, 59, 59
59, 19, 19, 19, 19, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00
00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00
13, 13, 44, 44, 44, 44, 44, 44, 44, 44, 44, 44, 44, 44, 44, 44, 44, 44, 44, 44
44, 44, 44, 44, 44, 44, 44, 44, 44, 44, 44, 44, 44, 44, 44, 44, 44, 44, 44, 44
44, 44, 44, 44, 44, 44, 44, 44, 44, 44, 44, 44, 44, 44, 44, 44, 44, 44, 44, 44
44, 44, 44, 44, 44, 44, 44, 44, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19
19, 19, 19, 19, 19, 19, 27, 05, 05, 05, 05, 05, 05, 33, 33, 33, 33, 33, 33, 33
33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33
33, 33, 33, 33, 33, 33, 33, 01, 01, 01, 01, 01, 01, 01, 01, 01, 01, 01, 01, 01
01, 01, 01, 01, 01, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22
22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22
22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22
22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22
22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22
22, 22, 22, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92
92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92
92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92
92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92
92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92
92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92
92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92
92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92
92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92
92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92
92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92
92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92
92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92
92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92
92, 92, 92, 92, 92, 92, 92, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31
31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31
31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31
31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31
31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31
31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31
31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31
31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31
31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31
31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31
31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31
31, 31, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33
33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33
33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33
33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33
33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 09, 09, 09, 09
09, 09, 09, 09, 09, 09, 09, 09, 09, 09, 09, 09, 09, 09, 09, 09, 09, 09, 09, 09
09, 09, 09, 09, 09, 09, 09, 09, 09, 09, 09, 09, 09, 09, 09, 09, 09, 09, 09, 09
09, 09, 09, 09, 09, 09, 09, 09, 09, 09, 09, 09, 09, 09, 09, 09, 09, 09, 09, 09
09, 09, 09, 09, 09, 09, 09, 09, 09, 09, 09, 09, 09, 09, 09, 09, 30, 30, 30, 30
30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30
30, 30, 30, 30, 30, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31
31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31
31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31
31, 31, 34, 31, 31, 31, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34
34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34
34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34
34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34
34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34
34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34
34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34

 

[wiztecy]

I think I'll take my Roadster in for a Bleed Scan/Test. I discovered since its under warranty its company policy to run it and its free.

 

[brianman]

Teach us new folk please:

What is the scale of these numbers? Is 100[%?] fully charged (or fully charge capable) or is it something else?

Also, what's the ordering sequence? Is it by row, then column within the grid structure? Or something else?

Thanks!

 

[Doug_G]

I think I'll take my Roadster in for a Bleed Scan/Test. I discovered since its under warranty its company policy to run it and its free.

Yeah, they run a bleed test whenever they get their hands on it. I think they want the data for their own uses.

- - - Updated - - -

Teach us new folk please:

What is the scale of these numbers? Is 100[%?] fully charged (or fully charge capable) or is it something else?

Also, what's the ordering sequence? Is it by row, then column within the grid structure? Or something else?

Thanks!

Those numbers are simply the brick number that reads the lowest voltage. They have no particular meaning except if you find that one brick is always the lowest. In that case you might be suspicious that there's a bad cell in it or something. There is no ordering other than date ordering.

The bleed test is much better, in that it briefly switches in a bleed resistor on each string in turn, so the measurements are done under a known load instead of open circuit.

 

[Alan]

I have 18 months with the same lowest brick. Ah capacity & ideal range have not changed over this time & 15K of miles so not sure that having one brick always the same is a big issue?

00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00
00, 00, 00, 85, 85, 85, 85, 85, 85, 85, 85, 85, 85, 85, 85, 85, 85, 85, 85, 85
85, 85, 85, 85, 85, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32
32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 91, 91, 91, 91, 91, 91, 91, 91, 91
91, 91, 91, 91, 91, 91, 91, 91, 91, 91, 91, 91, 91, 91, 91, 91, 91, 91, 91, 91
91, 91, 91, 91, 91, 91, 91, 91, 91, 91, 91, 91, 91, 91, 91, 91, 91, 91, 91, 91
91, 91, 91, 91, 91, 91, 91, 91, 91, 91, 91, 91, 91, 91, 91, 91, 91, 91, 91, 91
91, 91, 91, 91, 91, 91, 91, 91, 91, 91, 91, 91, 91, 91, 91, 91, 91, 91, 91, 91
91, 91, 91, 91, 91, 91, 91, 91, 91, 91, 91, 91, 91, 91, 91, 91, 91, 91, 91, 91
91, 91, 91, 91, 91, 91, 91, 91, 91, 91, 91, 91, 91, 91, 91, 91, 91, 91, 91, 91
91, 91, 91, 91, 91, 91, 91, 41, 09, 09, 09, 88, 79, 79, 79, 79, 79, 79, 79, 79
79, 79, 79, 79, 79, 79, 79, 79, 85, 85, 85, 85, 85, 85, 85, 85, 81, 81, 81, 81
81, 81, 81, 81, 81, 81, 81, 81, 81, 81, 81, 81, 81, 81, 81, 81, 81, 79, 79, 79
79, 79, 79, 79, 79, 79, 79, 79, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86
86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86
86, 79, 79, 79, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86
86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86
86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86
86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86
86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86
86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86
86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86
86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86
86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86
86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86
86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86
86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86
86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86
86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86
86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86
86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86
86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86
86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86
86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86
86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86
86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86
86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86
86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86
86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86
86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86
86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86
86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86
86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86
86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86
86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86
86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86
86, 86, 86, 86, 86, 86, 86, 86, 86

 

[Doug_G]

Beats me! Scott451 asked me to implement it... the idea behind it seems reasonable since Tesla thought to log this information.

 

[strider]

If you use the VMSParser app and run it w/ the "-b" option you'll get output like this:

timestamp, brickahmin, brickahave, bricknumber
11/10/2010 16:14:16, 156, 156, 73
11/11/2010 16:14:15, 156, 156, 73
11/12/2010 16:14:14, 157, 157, 70
11/13/2010 16:14:14, 157, 157, 70
11/14/2010 16:14:13, 157, 157, 70
11/15/2010 16:14:13, 157, 157, 44
11/16/2010 16:14:12, 157, 157, 44
11/17/2010 16:14:12, 157, 157, 44
11/18/2010 16:14:12, 157, 157, 44
11/19/2010 16:14:12, 157, 157, 44
11/20/2010 16:14:12, 157, 157, 44
11/21/2010 16:14:10, 157, 158, 44
11/22/2010 16:14:09, 157, 158, 87
11/23/2010 16:14:09, 158, 158, 91
11/24/2010 16:14:08, 158, 158, 45
11/25/2010 16:14:08, 158, 158, 45
11/26/2010 16:14:07, 158, 159, 45
11/27/2010 16:14:06, 158, 159, 45
11/28/2010 16:14:06, 158, 159, 45
11/29/2010 16:14:06, 158, 159, 45
11/30/2010 16:14:05, 158, 159, 45
12/01/2010 16:14:05, 158, 159, 45
12/02/2010 16:14:05, 158, 159, 45
12/03/2010 16:14:05, 158, 159, 45
12/04/2010 16:14:05, 158, 159, 45
12/05/2010 16:14:05, 158, 159, 45
12/06/2010 16:14:04, 158, 159, 45
12/07/2010 16:14:04, 159, 159, 45
12/08/2010 16:14:03, 159, 159, 45
12/09/2010 16:14:03, 159, 159, 45
12/10/2010 16:14:01, 159, 159, 45
12/11/2010 16:14:01, 159, 159, 45
12/12/2010 16:14:01, 159, 159, 45
12/13/2010 16:14:00, 159, 159, 45
12/14/2010 16:14:00, 159, 159, 45
12/15/2010 16:13:59, 159, 159, 0
12/16/2010 16:13:59, 159, 159, 89
12/17/2010 16:14:59, 159, 159, 89
12/18/2010 16:14:58, 159, 159, 89
12/19/2010 16:14:58, 159, 159, 89
12/20/2010 16:14:56, 159, 159, 89
12/21/2010 16:14:56, 159, 159, 89

In addition to the lowest brick # (last number on the right) it will give you the difference between the average brick's amp-hours and the lowest brick's amp-hours. If those numbers diverge (looking at my data, the largest difference I've had is 4) then that's another clue that you may have a bad brick and Tesla should take a look. I don't know what that number is, maybe 5 is ok, maybe not. It's also recovered and my latest data has a delta of 2. So as long as the lowest brick number is changing and the delta between average and lowest isn't getting steadily wider then you're ok.

As to the range drop, mine did that about a year ago. Was steady at 190-191 and then dove to 183 and it's held there ever since. Just more fun things to learn about EV's

 

[Alan]

Thanks Strider, it makes sense that the delta is more important than whether one brick is always lowest.

The graph below shows 2 and a bit years of data & 20,000 miles. I guess the delta is increasing a bit but not going to loose sleep over it yet. Interestingly the average Ah is still higher than when the car was new.

 

[wiztecy]

Thanks Strider, that -b option and extra info is helpful. I know Tesla can read the logs and identify if the battery pack is out of balance. Any idea how that's done? Possibly with the brick data wer're discussing here? I didn't mind mine dropped and know there's a sharp slope at the top of a battery curve in terms of its life and that curve tapers off. So the initial drop should be noticeable in terms of range.

I'm heading in this morning and having a bleed test run on the Roadster. I'll see if I can correlate any of this information with the bleed test results.

@Doug, yes it does appear Tesla wants to get logs of the Roadsters anytime they can get a chance. They should have an upload site... Sure people would be happy to contribute. I ordered new CF sills via phone in seattle, they don't sell the black inserted ones that're on their site anymore, only the silver plastic ones. They had to send the sills out to have them recovered, $150 extra for that. I mentioned about my pack dropping and they said send us the logs, we'll have our battery engineers look at it and see if anything looks unusual. Its actually nice, to have a concern like that and then instantaneously be able send the data out to their experts. Also every time your Roadster gets serviced they dump the logs and upload them to their database. Interesting thing is you can't get those back which makes me believe its not a record per vehicle but rather a database of information and how the batteries are degrading over time type of research. Possibly the tech's have a graph into this data, but most likely not.

Here's a link talking about LiPo batteries which has good technical info on the packs, they discuss balancing too:
Understanding RC LiPo Batteries

 

[Doug_G]

@Doug, yes it does appear Tesla wants to get logs of the Roadsters anytime they can get a chance. They should have an upload site... Sure people would be happy to contribute.

They do. Look at the PDF that is included on the TESLA memory stick you get with the car.