OpenEVSE salvages older JuiceBox 40 Pro

[bwilson4web]

INTRODUCTION
My older Jukeboxes from 2016 were abandoned by the new owner which shutdown the EVSE software management. Happily, OpenEVSE made a board that replaces the original board and regains EVSE software management.

BACKGROUND
The original Jukebox management required access to servers. But when VoltiE Group (Enel X) bought them, there was a distinct loss of support. Eventually, they walked away from North America meaning we could no longer tailor them for our purposes.

OpenEVSE designed a replacement controller board but there were problems:

• Multiple Juicebox models - different connectors meant the board had to deal with all variants.
• Abysmal installation instructions - not a 15 minute task unless you have the exact model JuiceBox described. My 2016, gray box, Juicebox 40 Pro does not have connectors inside nor LED lights.

"Some assembly required," a challenge that led to this post. Here is the before:

• "rats nest" - wiring bundled over the board.
• screw down wires - not connectors, individual wires
• some "leakage" - some mildly corroded parts

This is the final before closing the box:

• wires rerouted - all under the controller board so probe points are accessible for debug.
  • pairs are bound by heat shrink
• soldered - no more connectors

OPERATIONAL PRINCIPLES
There is no high-level schematic that maps how everything works together ... until now:

• NEMA 14-50 plug - primary power source. However, connecting to a NEMA 5-15 will turn on the board for initial software configuration.
  • 2.4 Gh local wifi network
  • time zone
  • sanity check
• 120/240 VAC power to +/- 12 VDC and 5 VDC logic
• DC Relay - power to throw double-pole replay
• AC TEST - makes sure the relay is working
• AMP CT - measures the current flowing to EV
• GFCI - looks for asymmetrical current indicating ground fault
• Test Coil - verify the GFCI is working
• Pilot - the control line to and from the EV J1772

All paired signal lines were collected in separate heat shrink tubes to make them easy to layout. The main power lines were bent to lay flat. The board mounts had extra nuts to make more space underneath for the control wires. All wires were soldered in place.

TESTING
In house testing used a NEMA 5-15 to NEMA 14-50 plug to power up the board and see the board mounted status LEDs. Ground, neutral, and hot are needed to avoid a ground fault.

The software came up with a local area network and web connected. An initial menu sets the future WiFi, password(s), and updated the firmware. However, a nuisance warning message shows up every 5 seconds, "Websocket disconnected ..."

Outside testing with a NEMA 14-50, everything booted up and it started charging the Tesla. WiFi connectivity worked so time to put the lid back on with silicone sealant.

CONCLUSIONS

• A fun project for this retired engineer, a marginal challenge to non-technical folks.
• Existing OpenESEV installation documentation is poor. This can happen when the designer doesn't realize how little the customer might know.
• Gray box, Juicenet 40 Pro - at least the wires were too long but otherwise, dam poor implementation.

Bob Wilson