Basically what I was thinking was along the same lines as what EVTV did to the Lear charger...see here:
http://store.evtv.me/proddetail.php?prod=Learcharger&cat=23 and there is a YouTube video of it all somewhere, but I can't seem to find it right now.
What they did was have an Arduino mimic the signals that the car would've given the charger and now they are selling the charger with the Arduino preprogrammed as a complete bundle, I was wondering/hoping that something similar could be done to the Tesla charger, meaning, having an Arduino mimic the car's signals and command the charger(s) to turn on.
Do you think that something like that could be done, even if it would require an external voltage sensor? What was required to make your charger work, and aside from the fact that it's currently a mess of loose wires, why is it not currently usable
Also, are you familiar with what signals the Lear chargers need? Do they receive an external voltage reading that could be used in place of a second sensor?
Mostly unrelated, but any chance you, or someone else, may have a spare charging connector off a Tesla? I'd like to put it on my car for if/when a Tesla HPWC is available but not a J1772 and just use Tesla's adapter for charging at standard EVSEs.
I want to mentioned first, and I've had this conversation with Jack... using Arduinos for this stuff, especially beyond the dev stage, probably isn't the greatest idea. These things are really not made for an automotive environment. At best, arduino is more intended as a dev platform to help get ready for a production version of a product, not something I'd ever install in my car... especially not controlling a critical system like a HV charger.
That said, no, it's going to be way more complicated to get the Tesla charger going properly and safely vs just strapping a CAN-enabled arduino to it and calling it a day. The charger relies on the Model S BMS for quite a bit. HVDC voltage and current readings from the BMS affect the charger. It expects the DC contactors to be opened and closed when the BMS signals they are, otherwise it faults and needs to be reset. It expects communication with the fast charge equipment in the car's HVJB and expects to be able to perform tests on that equipment, which is directly connected to the master charger and NOT via CAN. It expects communication with the charge port and expects the charge door and latch to be in an appropriate state and sequence of events in order to charge and or perform the fast charge equipment testing (ie, it would be a bad idea in a real car to test the fast charge contactors while the charge door was open and someone could electrocute themselves). The charger also needs a DC precharge circuit (normally inside the battery pack) since the DC side capacitors are not switched. There's also the high voltage interlock loop that needs to be faked for the charger to work, including the constant current signal. The charger also expects the BMS to announce the current HVIL current and voltage on CAN, and it expects to be able to perform tests of the HVIL at any time. If the "BMS" tells the wrong current, wont change the current for testing, etc, the whole charger faults and shuts down.
Additionally, the Tesla charger expects to be connected to a full J1772 EVSE. This is probably fine and actually would save a step when implementing in a vehicle, but is adding complexity to my project since I just want to power it from AC directly.
Further complicating things, the charger has a coolant flow sensor and expects the CAN data to match the actual coolant flow AND temperatures from the thermal controller in the car to match within a reasonable margin of what the charger is seeing. The charger also can command the coolant pump enabled/disable or increase/decrease coolant flow and it expects to see this change on its own sensors.
Then there is the high voltage isolation resistance measurements. The charger expects the BMS's HV isolation measurements to match its own. Oh, and the charger won't tell you what its is, so, you have to tell it the actual measured value at any given time within some margin of error, otherwise... fault!
Lots of this can be done with just CAN and some clever software, but a lot of it needs actual hardware to emulate signals and conditions the charger expects in certain states. It took me quite a lot of work just to get the thing to charge at 120V/5A for a few minutes.
Then add to that firmware changes. Tesla changes the firmware on these chargers all the time, sometimes drastically. For example, one charger I have expects a -100V offset to the DC target voltage. Another doesn't. Feed the latter a CAN message from the former's data set, and it'll fault and/or overcharge the battery.
Long story short, strapping an arduino to this thing is not going to make it work. It'd almost be easier to just make my own charger from scratch.
