MMC EVision 2

EV Instrumentation

EVisionTM – Universal EV gauge and Monitor for Battery Electric or Hybrid Vehicle


EVisionTM is very versatile and sophisticated instrument which allows monitoring, accurately measure and record many parameters related to an EV traction battery. It is designed mainly for use in pure electric vehicles, but since it is primarily a battery performance instrument (not a vehicle performance), it can be used in electric boats, buses, motorcycles, any type of hybrid vehicles, or in general in any application (including stationary) where its battery parameters have to be monitored. MMC has released the second generation of EVision. Similar to the first generation, it meant to replace older e-meter type of limited gadget and thus provide many more functions and flexible user configurable display options while getting rid of numerous e-meter shortcomings. EVisionTM not only acts as a “fuel gauge” of an EV or HEV, but also tracks (and logs) about 15 different battery and vehicle performance parameters. Any three parameters can be viewed at once on bright and crisp multicolor LED display – two parameters using digital readout and one – using 25 segments analog bar. User can assign any 3 parameters to any digital or analog readouts where respective unit identifiers are available, creating custom “page” of parameters user desires to view simultaneously. 20 such combinations (pages) are stored in memory and can be recalled by an HMI button, or using optional “favorite page” push buttons. Both HMI and push buttons are mounted remotely. Communication between main controller, HMI and Display modules is implemented via CAN bus. Data transfer between shunt measurement board and main controller is implemented via fiber optic link.

Here is example of randomly applied colors – any feature on a display can have its own individual color per request. You can also order display to match interior of the dash or vehicle by choosing custom color out of matrix of all available colors.

EVisionTM is equipped with vehicle’s stock analog fuel gauge driver allowing using existing fuel gauge on the dash as traction battery SOC monitor. The instrument is powered solely from the traction battery pack via integrated isolated DC-DC converter handling 60VDC…900VDC traction battery voltage span and does not require any other external power source to function. It will also monitor and display status of auxiliary on-board 12V battery, but does not use it as power source. Power consumption is about 3 W in running mode and about 300 mW in sleep mode.

EVisionTM is also equipped with galvanically isolated standard RS232C serial interface suitable for capturing continuously streaming data, configuring unit and updating its firmware. All streaming values are date/time stamped and always outputted (in readable NMEA ASCII format) whether acknowledged/captured or not. Corresponding PC software with GUI is included, but data capturing can be performed using upcoming serial data logger storing data to SD card.

EVisionTM consists of 4 sub-blocks: main controller PCB, HMI PCB (user interface), shunt measurement PCB and external or in-dash multicolor LED display. Included speed sensor is required for computing driving efficiency and show, vehicle speed, distance to empty, odometer and other related functions, but EVision is operational without speed sensor (related parameters will not be computed).

Assembled PCBs are sold without enclosures (to be installed in the battery box, power distribution box and under dash. Optional machined enclosure for the main controller greatly facilitates installation.

Here is the testimonial of the first beta tester John Wayland who installed and evaluated EVisionTM in his White Zombie – first world’s quickest street legal electric drag racing vehicle.

Main specifications are listed below.

Measured and displayed parameters:

Traction battery:

  • Instantaneous traction pack voltage, V
  • Instantaneous driving current in or out, A
  • Instantaneous charging current, A
  • Instantaneous power in or out, kW
  • Running Coulomb capacity Ah
  • Running energy, kWh
  • Running State Of Charge (SOC), %
  • Temperature (highest of 2 zones), °F or °C1
  • Indication of direction of battery current, OUT (drive) or IN (regen or charging)
  • Battery Cycle counter, full cycles
  • Traction battery imbalance detection and measurement
  • TTF (Time to Full) estimation in charging mode
  • Indication of charging status
  • Automatic drive/charge/idle mode detection

Auxiliary 12V battery:

  • Instantaneous voltage (V)


  • Current vehicle speed1
  • Energy consumption, Wh/mile and/or miles/kWh1
  • Odometer and Trip Odometer function1
  • DTE (Distance to empty) estimation1
  • Night time display dimming and HMI illumination
  • Sleep with wake up on ignition or charge
  • No power consumed from onboard auxiliary 12V battery, no such battery is required for full functionality.
  • Power steering pump programmable drive


  • Streaming running data out from the serial port
  • Download and Upload instrument configuration parameters, user preference, battery and vehicle parameters
  • Long retention of internal RTC setup for correct time stamping without power applied (~ 1 week).

External controls:

  • Stock analog fuel gauge drive
  • Charger disconnect timer
  • Power Steering pump control (OEM option only)

1Configurable for using Imperial or Metric units.

Main electrical characteristics:

  Display color   Specified by user at the time of purchase. Standard colors are White,
Yellow, Red, Green Blue, Purple. Any other RGB color – on request, see user’s manual.
  Measured battery current (drive/regen)   +/- 0.1 A…4,000 A (ranges 200, 500, 1000, 2000, 4000 A). Accuracy is 1% of top scale.
  Measured battery current (charging)   – 0.1 A…100 A (ranges 40A, 100 A). Accuracy is 1% of top scale.
  Measured traction battery voltage   60…800 VDC continuous, 900 VDC peak.
  Measured aux. 12V battery voltage   0…16 VDC
  Measured traction battery capacity   0…999 Ah
  Measured traction battery energy storage   0…999 kWh
  Measured traction battery relative SOC   0…100%
  Measured traction battery power   +/- 0…2000 kW
  Measured temperature   -35°C…+99°C
  Full charge cycles counter   0…65535 cycles
  Vehicle speed displayed   0…450 MPH (US),  0…600 km/h (EU)
  Trip odometer max value   999 miles (US),  0…999 km (EU)
  Power supply current (from traction pack)   9 mA @ 350VDC, 30 mA @100 VDC (running mode)

The model selection matrix guide.

External display dimensions  In-dash display front view dimensions External display side view dimensions

Custom color
selection matrix
Main window
GUI screen capture
EVision configuration
screen capture
Display configuration
GUI screen capture

Firmware and documentation downloads (EVision-2):

EVision-2 Set Up software for MS Windows (2.2MB zip file)
EVision-2 Main Controller firmware (SOCM.ENC file, (112kb zipped)
EVision-2 Display Driver firmware (EV_DD.ENC file, 59kb zipped)
EVision-2 user’s manual download (820kb pdf file)
EVision NMEA serial data string fields definition (14 kb pdf file)
RS232 streaming data string example (v3, 10 kb pdf file)
Collection of files – raw captured data, imported into Excel examples, etc. (902 kb pdf file)
CAN frame signals info (41 kb pdf file)
CAN node TX signals info (16 kb pdf file)
CAN node RX signals info (22kb pdf file)
CAN frames info (37kb pdf file)
CAN network info (10 kb pdf file)
ECUs info (10 kb pdf file)

PRICE: current MMC price list.

See user manual
Shunt dependant - see user manual
Fully isolated from traction battery