openinverter forum

Hi folks,

i'm not sure if this is the right place to ask this, but i was wondering two things when using the Leaf BMS and the Leaf Inverter with Johannes Board:

- Is there any possibility to prevent that the car "starts" (drives away), as long as the charging cable is plugged in. It happened to me several times that i forgot the charging cable on my Plug in Prius and the car then luckily doesn't start to drive.
- does the leaf charger lock the charging cable? Can this be controlled?

Thanks, Philip

Zapatero wrote: ↑Mon Nov 11, 2019 7:51 am Hi folks,

i'm not sure if this is the right place to ask this, but i was wondering two things when using the Leaf BMS and the Leaf Inverter with Johannes Board:

- Is there any possibility to prevent that the car "starts" (drives away), as long as the charging cable is plugged in. It happened to me several times that i forgot the charging cable on my Plug in Prius and the car then luckily doesn't start to drive.
- does the leaf charger lock the charging cable? Can this be controlled?

Thanks, Philip

I think we can put this thread among "General" section. Maybe it could fit into "EV car conversion hardware"

Normally to convert an EV you conform to some regulatives.
One is not to have battery negative tied to car chassis.
Another is to design charging system so that one cannot drive off with car connected. We are discussing this here.

There are two options that i tried.
1. Use a magnetic reed switch or microswitch on the tank cover and a line from this switch to GND. Idea of this switch is to "break" GND contact with some starting relay in the front of the car. We call this safety interlock. The best method is to connect GND side of your start relay to this interlock so that you cannot in any case make that relay start. Normally i connect here the red button too.
Normally you have to replace the microswitch on annual basis since salt and enviroment may eat it up by than.

2. Use a 230Vac picup lines from your charge socket and rout them to 230Vac relay. This relay would act as the switch in the first example and break GND on interlock relay. This example is a little less safe since in case if cable is not locked in EVSE and there is no 230Vac on power lines you could still drive off with a cable in the socket.

I will probably use Peugeot native magnetic reed switch that is fitted to fuel cap. However magnet was inside plastic cover that was part of the fuel hose which i removed. I will have to replace it with one Nd magnet with hole for a screw.
The signal i will rout to Arduino DUE which runs CAN for charger. This will signal Arduino to start charging function and send signal to relay in front to interlock.
Does anyone have another system?

arber333 wrote: ↑Mon Nov 11, 2019 8:36 am Does anyone have another system?

Most OEM EV's use the charging connector Proximity Pin to detect the cable. It works even if the EVSE is unpowered or faulty. Why not use that scheme?

https://openev.freshdesk.com/support/so ... -sae-j1772

Kevin Sharpe wrote: ↑Mon Nov 11, 2019 9:43 am

arber333 wrote: ↑Mon Nov 11, 2019 8:36 am Does anyone have another system?

Most OEM EV's use the charging connector Proximity Pin to detect the cable. It works even if the EVSE is unpowered or faulty. Why not use that scheme?

https://openev.freshdesk.com/support/so ... -sae-j1772

Screenshot 2019-11-11 at 09.42.34.png

Correct! I think now that EVSE connectors are standardized we can use this scheme. While i converted Mazda there wasnt firm standard, so i did what was safest at the time.

Kevin Sharpe wrote: ↑Mon Nov 11, 2019 9:43 am
Most OEM EV's use the charging connector Proximity Pin to detect the cable. It works even if the EVSE is unpowered or faulty. Why not use that

Perfect, i'll use that! Thanks!!!
Would it be possible to input the signal to the inverter, so that 1.5 Volts it wont start and at 4.5 volts it will run?

Zapatero wrote: ↑Mon Nov 11, 2019 11:34 am

Kevin Sharpe wrote: ↑Mon Nov 11, 2019 9:43 am
Most OEM EV's use the charging connector Proximity Pin to detect the cable. It works even if the EVSE is unpowered or faulty. Why not use that

Perfect, i'll use that! Thanks!!!
Would it be possible to input the signal to the inverter, so that 1.5 Volts it wont start and at 4.5 volts it will run?

Uh, i think this would be best used as separate uC. You could just use one Arduino Nano or even Pic12F! Point is this coupled with interlock relay prevents even to put inverter into precharge! By way of disconnecting GND from start relay you inhibit its function.
If inverter would go ahead and start precharge or even start DC switch you would have live inverter while charging from EVSE . Not safe at all!

Concerning the inverter you could

• Cut the forward and/or reverse pin
• Trigger brake input
• Theoretically: trigger mprot - but that is not brought out to the Leaf pin header

I wouldn't cut the DC switch (only), as the inverter will think it is closed and pull power via the precharge resistor if you try to drive off.
Whatever you do, make sure it doesn't trigger while you're driving

In Polo I use a 230V relay like Arber suggested. It triggers forward AND reverse to put inverter in charge mode. It only has a Schuko plug, so the only option besides error prone micro-switch

One fairly foolproof charge interlock was used on the Skoda Elmo. The build in charge cable used a standard domestic plug. That plug had to be inserted into a socket in the stowage compartment for the vehicle to run. Continuity was via the earth connection, so that was in effect tested each time.

Useful primer on J1772 charging standard (European standard is similar)

Just came across this picture from Mustang Mach-E. That door push button looks like a nice idea.