Since the first Tesla model S battery modules have arrived, I can proceed with the final layout of the engine bay. I created a new wooden prototype for the batterybox which is a little higher and shorter.
There is a little more spacing in between the modules, also where the new busbars are.
In the batterybox I already want to add the Lithium Balance BMS integration boards, a main fuse, coolant distribution and high voltage connectors.
The basic layout has now been finalised. The batteries and the controller will be next to each other. I made a prototype for mounting the controller.
I am going to attach the upper mounting tabs to the batterybox as well.
Next step was the support at the front which will hold both the batteries and the controller. It needs to be removable to be able to easily mount the engine and gearbox.
This requires quite some measuring and test fitting.
New Electric on Discovery
On March 14th finally the broadcast of the attempt of Anne from New Electric had its premiere on Discovery in Gamechangers: Inventing the World.
A nice documentary with next to the item about the crossing also an item about an electric plane which uses batteries from Kreissel Electric (one of the few with a higher energy density than those of a Tesla Model S). Unfortunately I have not been able to find a replay TV link online.
Remote control via iPhone
I am controlling my cooling system using Arduino, but you can do a lot more. I bought a GSM/GRPS/GPS Adafruit Fona 808 module.
By using Blynk I can easily create an App to read and control my Arduino remotely.
Blynk is a Platform with iOS and Android apps to control Arduino, Raspberry Pi and the likes over the Internet.
Even though the Adafruit Fona 808 module was in the supported hardware list, it took me days before I got it working. Using the Adafruit Fona library and directly via USB it worked OK, but not while using the TinyGSM library that Blynk relies on.
First part of the solution was to swap the RX and TX pins since these were mixed up in the documentation. After that connecting worked.
The strange signs were easily removed by selecting a lower, more stable baud rate. Unfortunately the module kept on reporting “Cannot init”.
The diagnostics run did pass however.
By combining some code from the diagnostics sketch I found out the TinyGSM library used the command “AT&FZE0” while for my module this needed to be “AT&F0. After changing that the module came online.
I created a test setup with just a led.
The led was connected to pin33 of my Arduino (green wire). I added a test button in the Blynk App on my phone.
And this enables me to switch the led on by pressing the button.
This will eventually allow me to switch on the battery heater or the two 150W 12V fans while the car is plugged in.