I’d like to add some LiFePO4 (LFP) to my 40ft sailing boat’s system, but I need some help in determining the circuit and selecting components. Any advice is much appreciated, particularly diagrams?
I’d like to leave the current lead acid (LA) based system as much as possible the same and add some Winston cells and external BMS. This is an augmentation rather than replacement application. A key requirement is to be able to run all the essential equipment of LA if the LFP goes down and to have the ability to replace capacity in remote locations with readily available LA.
I currently have 420Ah of AGMs. I would like to add 400Ah of LFP. I would like a system that I could add more LFP if required in future.
Charging sources are a 3kW generator, 460watts of PV, shore power and a standard alternator on a 53HP Yanmar. The PV recharges the AGM’s to 100% by midday here in the Med. The PV is four 115W panels in series/parallel through two Smart MPPT 20/100’s.
The loads are a 240VAC water maker and a small AC calorifier which currently only run off shore power or the generator. The windlass (12V/85A) and bow thruster (12V/530A), a 12VDC fridge and a freezer, navigation electronics. 12VDC LED lights and light computer use.
I have a an old 1500VA Mastervolt Dakar Combi inverter/charger which I think we’ll replace… possibly with a 3000VA Victron. Which is the best model?.... pros and cons?
The reasons to add LFP are:
1.to extend the time between PV charges to account for cloudy days and
2. to run an induction hob, a kettle and power tools off the batteries through an inverter and
3. maybe the 240VAC water maker and calorifier.