EVDash for Palm OS
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EVDash for Palm OS

EVDash is a Palm OS application that acts as a set of dash board gauges for electric vehicles. It displays battery pack voltage, amps being drawn from the battery pack, and two different estimates of remaining battery capacity. It works with Xantrex's Link 10, formerly called the E-Meter. Just plug the Palm device into the E-Meter, preferably through an optical isolator to protect the Palm device and start the EVDash program.

The main display shows the battery pack voltage in large digits at the top of the display with the current amps being drawn below it in the same size digits.

An estimate of the state of charge (SOC) is shown by the bars on the right side. The inner or left bar shows the capacity based on battery pack voltage under light load. The voltage drops as the capacity drops. The right or outer bar shows the capacity based on the integrated amps drown over time. The peukert effect is taken into account in the calculation.

The red "Rec" in the center left appears when data is being recorded. The drain at the bottom of the screen is the drain in amp-hours or if in meter mode it shows the drain in amp-hours and in kilowatt-hours.


Release Notes


Options menu

Once EVDash.prc is instaled on the Palm go to the Options menu to configure the software. There are several options dialogs.

SOC Settings... - allows the battery pack to be described to the program.

Record Settings... - used to specify how often samples are taken when recording.

Limit Settings... - the values used to trigger changes in color of the display and for audible alarms.

Input Source... - allows the input for readings to be changed.


SOC Settings

Pack capacity should be entered so that the state of charge (SOC) based on integrated amps over time can be calculated.

The peukert's constant for the battery type should be entered. This allows the effect of heavy loads to be compensated for.

SOC based on battery pack voltage under light loads uses the SOC voltage table.

The maximum amps is used only when generating simulation data.


Record Settings

Samples are recorded every time the difference in amps or volts exceeds a certain margin. That margin can be specified in the Record Settings dialog. Larger values will reduce the number of samples recorded. Smaller values increase the number of samples up to the one sample a second generated by the meter.


Limit Settings

Audio and visual cues can be set to trigger when amp or voltage limits are exceeded. If the check boxes on the audible limits are checked the alarms will be active for the values entered. The amps digits will change when the visual limits are exceeded and display in different colors on a color device or in different patterns on a black and white device.


Input Source

While the primary use of EVDash is to connect to a meter and to gather and display data from the meter, there are other times when alternate input sources are more useful. The two other sources are a simulator that generates random data and a playback source that plays back the current recorded set of data samples. A fourth option allows the input to be disabled so that the display does not change.

If the Simulation or Playback input is selected then an additional option is available to set the time compression. This allows data samples to be change in faster than real time.

Record menu

The Record menu provides access to features related to saving and managing recorded data samples.

New - Erases existing recorded data and resets the drain to zero.

Open... - Opens a saved set of recorded data samples.

Start Recording - Start or stops recrding data.

Save... - Save the current set of recorded samples to a named record set.

Delete... - Deletes a named record set.

Export - Exports the current data samples to a memo pad document in comma delimited format.



A list of the current recorded data sets is displayed in the list. A set can be opened by selected it in the list and clicking the Ok button. The selected set will replace any current recorded data samples.



This option saves the current set of samples to a named record set. A list of the current record sets is displayed in the list. If one of these sets is selected the name of the set is entered on the line below the list. The name entered on the line below the list is the name to be used for the saved set of samples.




Recorded sets of data can be deleted using the Delete dialog. A named record set can be selected and if the Ok button is pressed the record set will be deleted.


View menu

The current set of recorded data can be views in several ways.

List... - A text list of the recorded samples.

Graph... - A graph of the amps and volts over time.

Statistics... - A simple analysis of the samples.

Help... - Help for the application.



The List view shows every recorded data sample as three value, the time the sample was recorded, the volts, and the amps. The time is displayed as minutes and seconds.



The Graph view displays the volts and amps as they change over time. The time is the horizontal axis and the volts and amps share the vertical axis. The scale of the volts and amps adjusts as the range of each changes. The time scale can be set using the pulldown scale item at the bottom of the dialog.



Summary information of the recorded data is displayed in the Statistics view. The meter and calculated columns show results from either the meter directly or calculated values from the recorded data.

The mean peukert amps are the average amps adjusted for the peukert effect. This value is typically higher than the average amps. Aggressive driving with large current draws will cause this value to be higher above the average amps. Slow steady driving will keep the value close to the average amps. This makes the mean peukert amps a good indicator of how efficient the car has been driven.

Release Notes

  • Version 2.0 (9/25/2002)
    • Complete re-work of most of the application.
  • Version 1.1
    • Original application.
Downloads it here