ARCO Zeus Bluetooth Alternator Regulator Firmware Updates

This page is dedicated to informing users of the latest firmware updates for the ARCO Zeus Bluetooth alternator regulator. Here we will notify users of the latest firmware update as well as what changes those bring. 

The ARCO Zeus app can be downloaded here:
App Store
Google Play Store

Zeus Firmware v1.17

This version brings updates to the Temperature Compensation control algorithm, as well as new functionality for the “Duty Maximum (%)” as it pertains to the RPM Curve. 

Temperature Compensation

Improved functionality and responsiveness of the system to transition into Temperature Control mode.  The transition will occur 10°C before the Max Operating Temp as set for the alternator in the ARCO App, and the output current of the alternator is now secondary to its operating temperature.  The duty percentage (field) will vary to maintain the set temperature, as such a variable but steady output is to be expected from the alternator.  If through these efforts the alternator does not cool and the temperature continues to rise, all charging will be stopped if the Max Absolute Temp is reached (as set in the ARCO App). 

This graph shows an alternator under varying loads with a Max Charge Current of 100A, Max Operating Temperature of 100°C and a Max Absolute Temperature of 110°C.   Once the temperature reaches 90°C you will see the output current of the Alternator decrease as we are not trying to maintain max charging while covering house loads, rather our top priority is to keep the alternator at the desired Max Operating Temperature.

Firmware update temperature chart

*Test Duration is 45 minutes (click chart for full size image)

Scaling of RPM Limits Curve

When previously using the RPM Curve with an alternator that requires less than 100% field, the curve would be cut off at the Duty Maximum (%) set point.  For example, if you had a curve as shown to the right and set the Duty Maximum to 50%, then a straight line (red in image) would be drawn across the curve (*behind the scenes, not actually shown in app) and you would not see above 50% at any point on the curve. 

ARCO Zeus app RPM screenshot

With this update, when you set a Duty Maximum (%) the RPM Curve will be scaled by that factor so that you can utilize the entire RPM Range.  As shown, the engine rpm is at 1550.  If the Duty Maximum were to be set at 100%, then we would see a max duty of around 80% for this given RPM.  With the Duty Maximum set to 25%, every point on the curve is now scaled down to 25% of the value.  With the Duty Maximum changed at set to 25%, we now see at 1550 RPM the alternator is limited to 17% field.  This new feature allows you to use the full range of the chart from 0 to your Max Engine RPM set value with alternators that require less than 100% field.

ARCO Zeus app screenshot rpm