I am charging a lithium bank with a SmartSolar 75/15 controller. I have noted the following issues:
1/ The rebulk voltage threshold (float setpoint - rebulk offset) has no configurable detection time, so using a heavy load briefly causes the controller to return to bulk when it should stay in float because the state of charge (SoC) is still high. It would be very useful to be able to configure the "rebulk voltage detection time" so it could be programmed to a few minutes.
2/ The controller restarts a new cycle with bulk each morning, regardless of SoC. It is desirable for lead-acid cells, but NOT for lithium. Make this an option, so the battery can discharge over several days if needed before a new bulk phase is initiated.
Using the "remote on/off" feature to slave the controller to a BMS doesn't fully address these issues, because being able to have the controller in float at a lower voltage allows extending the discharge cycles by using solar energy for loads when available and this can greatly reduce the number of cycles on the battery over time. Ideally, I would like to be able to also force float (or not) from the BMS, but this would likely require hardware alterations.
