Update on Tesla Roadster CAC and Ideal Miles testing

So, I started a new thread at teslamotorsclub.com on this issue which has helped me a lot on figuring out what I can and can’t see on the vehicle.

So, I’ve followed some of the advice and used VMSParser and the Tesla Graphical Log Parser (Tesla GLoP) to copy the logs down from the Roadster and see what values are generated from it. Aside from OVMS, my favorite telematics product, providing me with realtime statistics on the vehicle. I love the nearly six years of user experience that are the long-time Roadster owners/community. They’ve created tools such as the two log parsing programs to extract knowledge about the vehicle.

I posted a sample of the last month:

timestamp, brickahmin, brickahave, bricknumber
6/9/2014 14:29:11 143.26 148.67 74
6/10/2014 14:29:09 143.14 148.62 74
6/11/2014 14:29:11 142.8 148.39 74
6/12/2014 14:29:12 142.63 148.05 74
6/13/2014 14:29:11 142.4 147.7 74
6/14/2014 14:29:11 142.63 147.88 74
6/15/2014 14:29:11 142.69 147.88 74
6/16/2014 14:29:11 142.97 148.16 74
6/17/2014 14:29:12 142.92 148.27 74
6/18/2014 14:29:11 143.2 148.62 74
6/19/2014 14:29:12 143.03 148.22 74
6/20/2014 14:29:11 142.8 148.1 74
6/21/2014 14:29:11 142.46 147.76 74
6/22/2014 14:29:12 142.63 147.88 74
6/23/2014 14:29:12 142.8 147.99 74
6/24/2014 14:29:13 142.75 148.1 74
6/25/2014 14:29:13 142.52 147.76 74
6/26/2014 14:29:13 142.46 147.42 74
6/27/2014 14:29:13 142.57 147.19 74
6/28/2014 17:09:38 143.03 147.59 74
6/29/2014 17:09:38 142.8 147.08 54
6/30/2014 17:09:38 143.2 147.36 54
7/1/2014 17:09:36 143.37 147.65 54
7/2/2014 17:20:32 144.17 148.39 54
7/3/2014 17:20:32 145.03 148.67 54
7/4/2014 17:20:31 145.03 148.67 54
7/5/2014 17:20:31 145.14 148.79 54
7/6/2014 17:20:33 145.14 148.79 54
7/7/2014 17:20:33 145.31 148.9 54
7/8/2014 17:20:34 145.65 149.3 54

And was advised that if the last value does not change for a while that it could be the issue (a bad brick that is dragging the whole sheet down.). The fact that the brick has changed throughout the month, shows that I probably don’t have a single deficient brick. In the thread, Kevin Sharpe showed his Roadster log values and shows what a bad brick problem looks like.

Aside from the self-help stuff, one of the advantages of purchasing a Roadster under the Certified Pre-Owned program, is the access to the SC at no additional charge (for warranty issues). I was already scheduled to bring the car into service for an issue with fogging in the headlights, so I had them look into the loss of Ideal Miles and CAC values.

So, the Service Technician/Shop Foreman for the Southern California Service Center that I took my car too have provided the following plan of attack after they’ve looked at the car (and did the bleed test, updated the firmware (to support the >70A bug)) considering that our annual maintenance for the Roadster is upcoming.

Since my better half’s daily drive is approximately 60 miles a day, he suggested that we drive the vehicle in Standard Mode and run the car down to about 10 Ideal miles for at least three times over the next month and charge back up in Standard Mode. On those evenings that the car has NOT been driven down to the 10 Ideal miles, we were advised to park it, but do not plug it in overnight. I’d like to track the vampire loss for the vehicle as we do this.

During an extended period of non-use, the tech suggested that we plug in the Roadster using storage mode during that time.

After the month, and possibly during the annual maintenance, they’ll look at what happened to the pack after these tests.

I did see some improvement in minimum CAC values over the past week since I did my test on July 2nd and July 3rd… So, we’ll see. Will report here (as well as on teslamotorsclub.com).

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Dennis

rEVolutionary armed with a Tesla Model S S85 and a Tesla Roadster, when his wife let's him borrow it. Formerly driving a BMW Active E (2012-Feb to 2014-Feb). Dennis has been driving EVs since he found himself on the BMW Active E trials on February 2012. As a result of his involvement in the Active E program, he became Accidentally Environmental. Aside from this blog, he often tweets @dennis_p. When not driving, he can be found on the following Tesla/EV forums - teslamotorsclub.com, teslamotors.com, and model3ownersclub.com as AEdennis or on speakev.com as Dennis. In the interest of full disclosure, Dennis has an inherent bias toward electric vehicles and has an investment in and is LONG Tesla (NASDAQ: TSLA).

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