Over the past month I have been doing live test runs of the revised Alternator Regulator in 'stand alone' mode; where is senses voltage locally and acts accordingly. During this time I was working on the CAN protocol to allow communications between a battery monitor and the regulator. After several hardware simulations, and a few short live trials, today I made a longer (2hr) trial run of the new CAN enabled Alternator Regular working in sync with a battery monitor via the CAN bus. Initial results look very promising!
For this latest run I disconnected the battery voltage and current sensing wires from the battery and placed them instead on the alternator. Then using a mocked up Battery Monitor (Arduino Due with an INA226 grafted in) I was able remotely relay the battery voltage and current back to the regulator via the CAN bus. to keep battery voltage typically within 5-10mV of its goal (max 20mV). And this is all while there was a 400mV different between the Alternator output and the battery due to voltage drop in the heavy DC cables.
Over the summer I will make more trial runs, and will be releasing the new hardware this winter. There is more to come, but for now here are some of the capabilities enabled by the CAN feature:
- Remote battery voltage instrumentation: No need to run separate wires to the battery, all communications occurs over the CAN bus.
- NMEA-2000 type status reporting on Alternator output, as well as Battery status.
- Coordination between several charging sources using standard RV-C protocol.
- Fall-back safety modes in regulator in case of CAN bus failure.
And as foreshadow, if there is enough interest in this design I might look into having a batch of them professionally assembled. No more hand soldering!