Tuesday, January 1, 2013

The Washington D.C. SOC Meter Built-It Project

The parts list is derived from this MyNissanLEAF post and the tentative sources for each part is as follow:


  1. Why would anyone want one of these? Doesn't the Leaf already have a fuel gauge?

  2. The Fuel gauge is notoriously inexact. The official VCM report on the battery is in about 281 to 4 (Dead) with each GID measuring about 80 Wh (0.08kWh) of the battery pack's 22.48 usable capacity. This is at least 20 times more accurate than the standard 12-bar gauge but actually is linear rather than the 12-bar where the top bar represents more than 9% of the total battery capacity. This would allow owners to see what their true loss is after 1 year in D.C. as opposed to not knowing anything until the first bar drops. The F1.09 Firmware of the unit as built, thanks to Gary, would have the following toggled settings available in addition to SOC:

    Mode 1: GID and SOC Data Mode
    V1: GID-Percent: Shows the CAN-bus "GID" value as a percent of 281 (for example, " 81.1").
    V2: GID-Raw: Shows the same "GID" value in its "raw" form (roughly " 0" to " 281").
    V3: Real-SOC: Shows the "Real-SOC" percent with a "C" prefix (roughly "C 0.0" to "C95.0").

    Mode 2: Battery Pack-Output Mode
    V1: Amps-Out (for example, " 27.3"), where negative values are Amps-In (charging).
    V2: Volts (for example, "387.3"), where values are typically between 300 and 400.
    V3: Power-Out in kW (for example, "P24.3"), or Regen and Charging (for example, "C 8.3").

    Mode 3: LEAF Logging System Mode
    V1: Disp "LLS " while logging to give the uP more time (if needed) to process CAN messages.