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:
Zeus Firmware v1.22
This version is the same as 1.21. The version number had to be bumped one to re-sync with the new app release that was done at the same time.
Zeus Firmware v1.21
- Lithionics Battery Aggregation Support
The latest firmware introduces battery aggregation support for Lithionics batteries connected via CAN network, enabling safe and efficient charging of up to 9 batteries simultaneously. The Zeus Regulator’s algorithm cycles through data from each battery to determine optimal charging parameters, including Target Voltage, Target Current, Reference Temperature, and Target State of Charge (SoC). This update provides users with an efficient solution for managing multiple batteries in parallel, ensuring safe operation by avoiding battery overcharging, overloading, or overheating.
- Battery Integrations for Expion360, Renogy, EcoFlow, and Epoch
Arco Zeus introduces additional battery follower modes for Expion360, Renogy, EcoFlow, and Epoch lithium batteries. This update allows users to receive battery data and charging control parameters directly from their supported batteries via CAN bus communication.
- Integration with Firefly 2.0
The firmware was updated to support Firefly 2.0 OS.
- Refined ‘Tachometer Required’ Functionality in Follower Modes
The latest firmware update refines the ‘Tachometer Required’ feature in follower modes. Charging is now automatically halted if Zeus lacks RPM data while the ‘Tach Required’ setting is enabled in the Zeus app. However, charging can proceed without tachometer/RPM input as long as the ‘Tach Required’ option is toggled off, offering users greater flexibility and control.
- Intelligent Charging Parameter Selection in Follower Modes
Zeus now compares charging parameters (e.g., absorption target voltage and maximum allowed current) received from supported smart batteries in follower mode with the user settings in the Arco Zeus app. It automatically chooses the safest charging option (lowest value). Users can choose to set their own parameters for greater control or rely entirely on the battery’s BMS to handle charging, offering flexibility to suit any preference.
Zeus Firmware v1.20
This version brings DVCC Compatibility to the Victron Follower sync mode.
Victron Follower
Integrates with Victron’s DVCC charge protocol. An alternator shunt is REQUIRED for this mode to function properly, as a charge input device must be able to measure their input into the system.
To setup and configure your regulator, follow these steps:
- Enable and configure the alternator shunt in your Zeus App.
- Set the ‘sync mode’ to Victron Follower.
- Set the ‘Max Charge Current’ (Settings -> Battery) to the maximum current you want your alternator to contribute to charging.
We use the Battery’s ‘Max Charge Current’ setting as the limit for what the Zeus Regulator will allow DVCC to ask for, and what we will control the alternator to output. If you set your Max Charge Current to 100 amps, we notify the GX Device that we can contribute UP TO 100 amps to charging. If a higher amount is requested, we will let the GX device know that is out of range and that our max is 100 amps. You can only increase or decrease the charge current by changing this value in the Zeus app.
Zeus Firmware v1.19
Used as a Beta version for DVCC Testing and Implementation.
Zeus Firmware v1.18
This version brings updates to the Victron Follower sync mode, as well as having the foundation for DVCC Integration.
Victron Follower
This sync mode formerly listened to Victron messages for any errors or flags which were indicative of a “don’t charge” state. If or when such a message was seen, Zeus would stop charging. All of the Charge Profile parameters came from the ARCO App and were set by the user.
In this new implementation, Zeus will follow the charge parameters (Max Charge Current and Absorption Target Voltage) and state (Bulk, Absorption, Float) as set by the Lynx BMS over the CAN-Bus. If these values are set in the ARCO App and then saved to Zeus, they will be immediately overwritten by what the Lynx BMS is wanting for the batteries. For changes to the charge parameters (charge current and voltage), you will want to set these on the Lynx BMS. All other parameters inside the ARCO App are still adhered to (min and max temperatures and voltages, rpm curve, etc.).
Here are examples of before and after settings from a 12v Victron Follower setup with one Lynx 500 BMS, and 12v 100aH Victron Smart LiFePo4 Battery. The desired charge voltage and current from the Lynx 500 BMS have been updated and are shown in the ARCO App.
Connection diagram:
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.
*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.
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.
