Support

Hey all,

I gave up on Voltie’s transition of the Juicebox. I really need the ability the adjust my amperage and I worked with their support for weeks. All they ended up doing was making my Juicebox a dumb charger stuck at 40 amps again.

So I gave up an ordered the OpenEVSE board. It was working great and the interface is perfect. But I ran in to an issue trying to charge my PHEV. My EV charges fine in my garage. It plugs right in to the Juicebox v2 with OpenEVSE and I can adjust the amperage.

The PHEV is a different story though. I park it outside and we don’t use it much. Since it’s far away, I’ve always used a j1772 extension for it. I have one I’ve been using from Amazon that used low gauge wiring. That was my primary concern and this was one of the few (if any) that actually had 8 awg wiring.

https://a.co/d/bdrSb3c

I’ve used this with my portable EVSE and my Juicebox and it always worked fine with no issues. But when I switched to the OpenEVSE board in my Juicebox, it now won’t charge the car anymore.

Both the EVSE and the car see that it is plugged in. But it won’t start charging. If I move the car in to the garage and use the cord directly, it charges without any issues. 

The only thing I thought to do was to turn off the safety features in OpenEVSE. I tried that and it had no effect. I also tried adjusting the amperage down to 8 amps to see if that would work, it had no effect. I’m not sure what else I can do.

I’m guessing there is something with a drop in ohms because of the length? But I don’t have a multimeter to check anything. I also need the 40 foot length.

Anyone have any ideas on how I can get this to work?

Thanks in advance!

Anyone have any thoughts about this? I tried my travel extension cable and it has the same problem. But when I use my portable level 1 charger as well as my portable level 2 charger, they work just fine. Just the OpenEVSE board refuses to charger over the extension cables.

I asked AI how does the J1772 communications work and got this response and what I gather the square wave drive circuit on the OpenEVSE might not have the same 'umph' the other EVSEs have. But you can probably test it with an O'scope with and without the extension then with and without a load resistor.:

J1772 communication uses analog signals over the Control Pilot (CP) and Proximity Pilot (PP) pins to control and monitor the charging process. The EVSE (charger) sends a 1 kHz square wave on the CP pin, and the vehicle responds by changing the resistance on this line, which alters the square wave's voltage. This voltage change allows the system to detect vehicle presence, inform the vehicle of the maximum available current, and regulate charging by communicating different signal duty cycles. The PP pin also provides a crucial "plug present" signal to prevent vehicle movement during charging.

Ah yeah, that’s what I was thinking too. I wish there was a way to boost this. Not sure if it is a physical part limitation or something in the software. But I’ve tried with multiple extensions now and none of them work. I’ve also tried my multiple extension cables on 6 different other EVSEs now and all of them work. If it’s just the software, it would be awesome if they could push out an update to boost that signal a little bit.

Thanks. Is this something I can change through the web UI?