Managing 2. Adding a vehicle and making it the main.

[fran-6co]

Hi all,

A few days ago, I was lucky to pick up a new Model Y Standard from the EU, and I previously checked how to add it to my Teslamate instance. Very simple, just restarting the Raspberry Pi will show it. It did. Bravo!

However, it is not that easy to work on the dashboards. For example, I check quite often the Battery Health, and I found the variables are shared between my two cars. But in reality, this differs a bit. One is 60 kWh when it was new, and the other is 61.9 kWh now (new), which is normal to have different variables for both cars.

Note: the Model Y has a negative degradation because there is only one variable shared for both vehicles.

How should this be managed? Is there any simple change? Would it be better to have another Teslamate instance?

I am confused a bit and wanted to share and read your opinions and experiences when managing two Teslas.

[isnsaka]

When I added my second Tesla to TeslaMate, I ran into the same confusion. At first everything looked fine because the car showed up automatically after a restart, but once I opened the Battery Health dashboard I realized something was off. The degradation numbers did not make sense and one car even showed negative degradation.

What I eventually understood is that the Battery Health dashboard uses shared custom variables. The fields like custom battery capacity when new and custom max range when new are not tied to a specific vehicle. They apply globally to the entire dashboard. So when you switch between cars, both vehicles are being compared against the same baseline. That is why your Model Y shows negative degradation. It is not actually gaining capacity. It is just being calculated against the wrong reference value.

In my case, I did not create a second TeslaMate instance because that would add unnecessary complexity. Instead, I either duplicated the dashboard and set separate baseline values per car, or adjusted the queries so they calculate the maximum historical usable capacity per vehicle. Once the baseline is car specific, the degradation numbers become realistic again.

So the issue is not TeslaMate itself. It is just how the Grafana dashboard variables are defined. Once you separate the baseline per vehicle, everything behaves correctly.

[JakobLichterfeld]

Yeah, and any PR to handle these battery variables via DB is welcome.
If you want to remove the old vehicle: https://docs.teslamate.org/docs/maintenance/manually_fixing_data#remove-a-vehicle-from-the-database