DIY EV Part 36 - Connecting up the HV Junction Box Plus a VERY quiet test run.

[@MrNhenwood]

Nice to see the addition of the Arduino into the controller. With the timing, you'll find that it changes with the voltage of the battery pack, and the temperature. One way of working around that is to measure the voltage drop of the per-charge resistor. This means that regardless of the conditions, the timing will always be correct, and the contractors as safe as they can be for this issue. Well done tho, it's a build I watch closely and wait the next episode.

[@alibro7512]

Thanks, I was planning to set a fixed precharge of around 2 seconds to be safe as I'm not experienced enough to try to be clever about it. Do you see any issues with that?

[@FrankGraffagnino]

super awesome progress! thanks for taking time to walk through your contactor setup. and thanks for taking time to film everything. the amount of people that can watch this now and in the future is huge! very interesting the way you have the arduino. question - do you think the reliability of the arduino will be enough for an automotive application? not just environment wise like heat and vibration, but like... if it runs for a long time and has some buffer overflow or something odd and resets... normally most people wouldn't care but i think in that case you entire car will reset as the contactors are opened. i may be worrying about nothing though... perhaps the sketch is so simple there is very little chance of that happening.

[@alibro7512]

Thanks mate. You make a good point about Arduino but I think they are pretty reliable as I've seen them used successfully in industry. For that reason though I bought a genuine Arduino Uno and for the charge control will be using a genuine Due. The code I'm using is ultra simple but I'll post it in Openinverter for others to take a look at and check. My coding is very poor so is mostly copying others and making small changes. Also it is powered by the ignition so is very simple to reset although I hope that won't be necessary.

[@ruggedplus]

Thank you for your video. Very informative and a build well done! Quick question. Aren't the main contactors polarised - i.e. it matters that the current flows from terminal A1 to A2? However in your connection the current would flow in one direction when powering load (e.g. drive unit) and in the opposite when charging. 🤔

[@alibro7512]

Hi thanks. No they are not polarity sensitive. They're really just heavy duty relays. The reason for having the charge connection's on the that side of them is you don't want the charger live all the time. 😉

[@JamieJones1985]

Doesn't your leaf board handle the pre charge and contactors?

[@alibro7512]

What do you mean by Leaf Board?

[@JamieJones1985]

@@alibro7512 logic board or zombie board that controls the inverter

[@alibro7512]

@@JamieJones1985 I have a board made by Damien Maguire a few years ago for the Gen1 Leaf so while it probably could control the contractors TBH I haven't even tried. It is working and I don't want to risk damaging it or messing up the vehicle control. After this video was taken I made a point of soldering the connections between the Arduino and the relay board, then hot glued them together.

[@oldboyoverland]

Amazing - Good work - Fancy doing mine next? :P

[@alibro7512]

Sure! If you don't mind paying an old fool thousands for standing scratching his head half the time. 🤣

[@oldboyoverland]

@@alibro7512 - Deal! ...