Hello All,
What charging precedence strategy are you using with your REC-BMS-controlled-Victron-Energy-LiFePO4 marine battery system?
I have Multiplus-IIs, Wakespeed WS-500, MPPT solar charge controllers, battery chargers all connected to the Cerbo-GX. My charging will be through the main engine alternator, shore power connection, and the solar charge controllers. The strategy needs to accmodate dock-side charging, at anchor and underway with the main engine until I raise the sails, at which point I will either rely only on the 1100 watts of solar, or the generator (as needed). I think that VE has the ability to prioritize charging, but do not know how well it woks. I plan on looking into it today.
What technique are you using to program your system to use the cheapest charging sources?
If there is an existing thread, I have not found it.
Thanks!
Bill,
I've been living with a similar setup for several years but have no Wakespeed. I've found the Victron, without any "precedence" programming, does the right thing. If solar is putting 2000 watts of power into the batteries and I start the generator, I do see a dip in solar output, but not much.
The biggest observable problem is battery management while on the dock. The system, by default, keeps the batteries fully charged. When any electrical load is turned on, the demand is passed right through to the shore power input rather than using the battery. I would rather have my solar panels carry the bulk of the charging. Additionally, I don't want my lithium batteries sitting there fully charged.
I posted a question on the ABMS forum asking if anyone had a solution to this "shore power" issue. I also posted on the Victron Community forum. Recieving no input, I devised a scheme using the "large image" capabilities in the Victron Cerbo. The large image provides Node-Red and Signal-K - which open up a whole world of custom programming capabilities for a propeller-head like me. I wrote a Node-Red scheme that puts the Multiplus units into Inverter-only mode when battery SOC is over 70%. When charge falls below 50%, they are placed in "On" mode - allowing them to charge up from shore power to 70%. In practice, this keeps my batteries at a healthy charge level and it allows solar to do the bulk of the work. I only use shore power when it's cloudy for several days. I turn this on and off using a pushbutton on my breaker panel.
I've been using this sheme for about 2 years and it works great. Lately, I've been seeing another, easier way to achieve this functionality. Others have used the generator start capability of the Cerbo to trigger an "ignore AC" feature on the Multiplus. This would require wiring a digital output from the Cerbo to the Multiplus I believe. Here's a video describing the method: https://youtu.be/4ZsGHi8nKGc?si=GtodlxzfTTHhGZOa.
