Tapping into J1772 input power

[jsantala]

I don't know if this has been discussed in another post, so please link to it if needed, but has anyone tapped into the mains input power coming from the J1772 connector? I was thinking I'd add a cabin electrical outlet by stealing the input from the J1772. Perhaps this could be accomplished at the charger? The idea is that instead of charging at the usual L2 16A, I'd get a cable with directs the charger to use only 6-10 amps, so I could use a few amps for a cabin heater. This way I wouldn't have to add yet another ugly inlet to the vehicle.

 

[siai47]

I am sure it could be done. The wires coming from the J1772 port are easy to get to if you remove the rear bumper cover. I don't know if where you are located there are different mains voltages available from the J1772, but in the U.S. the problem would be the possibility of having 120 volts or 240 volts at the point that you tapped the power from. If you are looking for cabin heat, can't you just turn it on when needed with the remote when connected to a EVSE? I don't know if this feature is standard or not in Europe or not but it is standard in U.S. vehicles.

 

[jsantala]

The Citroën C-Zero, at least 2011 model, doesn't have the heat option on the remote, so I'll need to figure out a way to heat the car some other way.

 

[martinwinlow]

I was going to look into this soon with winter coming round again. I was hoping to rig up a mains hairdryer in the passenger footwell on a timer to pre-warm the cabin for early starts (as the iOn doesn't have the Remote System that the US version of the i-MiEV has) and powered from the car side of the J1772 port - assuming mains power is connected. Looking at the wiring diagram it looks quite possible but I don't know if, once the car has stopped actually charging, the 'brick' in the standard charging cable disconnects the mains... it has a contactor inside - I've looked! MW

 

[PV1]

That's going to be an issue. The power to the car is cut off when the car is done charging. Unless you can time charging to finish right before you leave.

 

[jsantala]

Yes, that is true and a problem. The EVSE will cut off mains power using a small contactor when it's not needed anymore.

 

[martinwinlow]

Given that the 'brick' and its contactor is only reacting to something changing on one of the 'signal' pins in the J1772 connection, surely it might be possible to fool the 'brick' into switching the mains back on for the duration of the pre-heating? Maybe having a small relay-based device that disconnects the J1772 socket (car side) signal wire and connects it to the right signal or resistance or whatever is needed? It's already getting a lot more complex than just wiring in the heater/timer but I don't think it is a massive technical hurdle... MW

 

[Don]

The idea is that instead of charging at the usual L2 16A, I'd get a cable with directs the charger to use only 6-10 amps, so I could use a few amps for a cabin heater. This way I wouldn't have to add yet another ugly inlet to the vehicle.

That could be done fairly simply, so long as you don't mind the heater shutting off when the charger does

But, why not keep it really simple? Use a separate extension cord for the heater and just stick it in the rear hatch and lock the car? You don't really need another ugly outlet, do you?

Don

 

[martinwinlow]

But that would require another supply socket and a lot of faff having done it before with another DIY EV. MW

 

[jsantala]

Would anyone happen to have more detailed info on how to access the J1772 connector from the inside?

What I'm thinking about now would be to splice another plug to the back of the J1772 connector, add an EVSE and a plug inside the car that I could use to charge at a slow 6A pace without leaving my J1772 cable hanging outside.

Essentially a bit like this setup here:

https://github.com/kortas87/simple-evse/wiki/ReferenceOutlander

 

[PV1]

The wiring for the J1772 can be accessed under the motor room lid. You could run your wiring under the gasket of the lid and up inside the car. I'd probably use some tape to help close up the gap you'll make with the wires to keep dust to a minimum.

Some interlocks (more or less a few relays) may be needed to prevent both plugs from being live at the same time. I've come across diagrams before, but I can't remember where I found them. A manager of a fleet of LEAFs modified the cars to have rear J1772 ports and I believe he wired in with the relay interlock so the front port isn't live when the rear port is in use.

 

[jsantala]

Thanks, I'll have a look under the lid. I've got about six months left on the 5 year powertrain guarantee. I might have to sit that out still until I go full monty on the modifications. Unless I get anxious as I usually do and just get on with it.

Since I'm the only user of the vehicle, I'm not expecting anyone else to stick a J1772 pistol on the car while I'd be charging from my hacked port inside the vehicle. Or open the charging lid and start stickin nails into the pins. It's worth a Darwin award if one does.