The heat is on

[Warlock]

"Have done some thinkering" 


https://youtu.be/4ZurvGWBQa0

[BauDemo]

Great work!
Can you put more detail on what you did?
I don't need this now, but would be good to know that I can replicate it if needed.
I can even put the instructions on evmonitor.info if you like.

Also - what is the orange box to the left of the heater?

[Warlock]

Thanks, and yes

I will document it further after some more testing. Hopefully we now might have a permanent solution for heating.

It' s a electric heater from a Chevrolet Volt made by Eberspächer. (Its also found in Opel Ampera and several other cars) it is activated by Single-wire CAN messages. They are quite commonly available for 1500-2500kr used, or about 5000kr new. (I have a few for testing and might sell them for cost if this turns out to be stable.)


I also made a teensy 3.2 based controller for it and only activate the heater if one get he heating signal from the car and the voltage is above 14V (the DC/DC is running, contactors closed, and precharge passed). I've put the circuit-board on OSHpark but i need to do some small revising. The same goes for the code, i will put it on github or something if anyone wants it (some tweaking remains).





The orange box is a waterproof box containing fuses. I've had to take out the PCU two times to replace fuses when the MES-DEA heater was still (partly) working. So now i have 30A in the PCU and 20A fast fuses in this box. The heater should never draw more than about 10A at current software so it should be safe. One could also just find the right connectors and make a straight cable.

[Warlock]

For the record, I've also tested a couple of other units.


The one form VW Golf/eUP! uses LIN-bus, I made a capture of one from a demo-car a couple of years ago, but the LIN-controller I had then must have been too slow to pick up all messages (so my progress halted). This unit is even smaller than the one I ended up using, so it should fit well even tho it has the inlet and outlet in the same direction (some more venting might be needed). Even the power-cord has the same connectors as the Think City so if 400V scares you, this one very nice. One can find it used for a reasonable price.



The heater in iOn, iMiev, cZero is quite a lot bigger and might be a bit more of a hassle to fit. On the positive side, this unit is very simple and easy to control. it even has two built in NTC thermistors. One activates 3 different PTC elements with just seting a line above 3V (so both 3.3V and 5V controllers work)

12V on pin 1,
PTC1 on pin 3,
PTC2 on pin 4,   (this PTC element is smaller and drains about 1.5 Amps, less than the two others)
PTC3 on pin 5,
Ground on pin 6,
NTC1 on pin 7,
NTC2 on pin 8

A proper power-cord must be made (I haven't found the correct HV mating connector for this unit online)
These are available for about 2000kr from several used part dealerships.

These heaters were form cars from about 2013

[BauDemo]

Thanks for all the details!

[mohpet]

The orange box is a waterproof box containing fuses. I've had to take out the PCU two times to replace fuses when the MES-DEA heater was still (partly) working. So now i have 30A in the PCU and 20A fast fuses in this box. The heater should never draw more than about 10A at current software so it should be safe. One could also just find the right connectors and make a straight cable.

This looks for me as the solution that really should be in the car from the start, with the fuses outside of the PCU. My PCU was upgraded to 2x25A a long time ago when one fuse blew due to a Mes Dea heater, but now I'm stuck again with only one fuse working after the Calix blew one 25A last spring.
Would one consider this solution safe, taking almost 400V out ie with external fuses? Any thoughts on this anyone?

[BauDemo]

The cables with 400V are there already - I don't see a problem with the fuses. And the box is orange, as it should be.
It looks solid as it is - the box is mounted on the plate and the cables are protected.
There could be heat-crimping sleeves on the 3 connectors that don't have them... but that is a small thing.

[Warlock]

Yes, I consider it quite safe, at least as safe as the mes-dea, which has its cables crimp-joined and extended in the middle. There is a grounded sleving which turns off the engine if stray-currents are detected in the first part. I did not extend this for the last 20cm (just like the Mes-Dea did not either), but the heater has something similar, tho that would not turn of the car :/
(actually, when I think of it, it might. the grounding is connected external to the chassis of the car, so the car might detect a connection between HV-lines and ground. I'm not quite sure how this is set up in the Think)

For the heat-shrink sleeves I agree they could go over the first crimped then soldered connectors, but as long as it is inside the box I believe it does not matter. there are heat-shrinked tubes with glue through the PG nipples, so it should be quite waterproof

[mohpet]

I agree this looks safe.  And the cables are already there, with the Mes Dea.
I got the Think PTC installed last autumn, with that solution there are no joints out there, only one HV cable going directly into the cabin.

[Warlock]

Yeah, the PTC in-cabin air heater is a very good soluution, specialy since every Watt drained goes to heat in the cabin, and nothing is lost in heating the engine compartment. Unfortunately they are hard to come by.
I tried to get hold of one, but noone wanted to sell me one. (Well, one wanted to have my entire car sent to Oslo and do the install there, but it is in daily use and it would be quite expensive)
The regulation for such a unit would be easy to do since it is PWM controlled, so one just had to pick up the heat-amount signal from the adjustment nob if one wanted to hack it in there one self

I'm still wondering if the similar CAN (but internal PWM) controlled PTC coupe-heater from a Tesla would physically fit in the heater and blower assemby in the Think...
(like this one: https://ebay.us/duWxbq)

Anyway, the solution at the beginning of this thread is the least intrusive and fully reversible solution I'm at now. I will post more info about that solution later.

[Warlock]

Just a heads up. We've started thinkering with the original PTC air heater made for the Think, which Arnie has installed in his car. Unfortunately this unit didn't work properly, and it gave no heat. I'm happy to report that we had some progress, but there are quite some more to test out on this heater, and further monitoring and testing is due in the close future (after a short vacation).

Anyway, a simple test with a 1Hz square wave, 50% PWM, at 12V delivered on the control pin on the heater (middle pin on the contact originally for the water-heater) activated the heater and it at least gave some heat. So yeah, the "the Heat is On" here as well.
Will come back with more...

(BTW Worry, I'm sorry for not starting to figure this heater out earlier. I guess it's been a few years since you sent one to me)

[worry]

No problem Warlock. Exciting. Good luck. :-)
I have not mounted any of those Miev heaters yet either, despite I have everything ready. Too many things going on. And I'm slow....