Ben Stein, over at Panbo, has just published a good review of the new Victron NG LiFePO4 batteries and related BMSs, well worth the time to read for most any cruiser who is even faintly interested in lithium batteries.
I won’t try to duplicate the excellent job Ben has done describing what makes this new system from Victron exciting, but rather I’m going to highlight a few things that jumped out at me as probably1 making this a good option for offshore cruising boats, particularly when paired with one or more Lynx Smart BMS NG(s):
Assuming this system proves to work as described by Victron, and we build a system with two paralleled NG BMSes with a NG bank split between them, is the seamanlike system requirement for a lead acid bank in series to power critical loads eliminated?
There can still be good reasons to include at least some lead acid battery capacity in a system with paralleled Victron’s BMSs. One example is including a charging source (such as a Watt & Sea hydro generator) that is not capable of DVCC into an otherwise DVCC-enabled system. One way to accomplish that is to have the non-DVCC charger connected to a separate battery that is in turn connected to the main lithium bank with a DVCC-capable DC-DC charger.
I consider DVCC to be one of the key competitive advantages of going with a Victron lithium battery system, but something that Stein fails to mention is the very limited selection of DVCC-capable components that are also fully ABYC compliant. This is particularly true for chargers, inverters and inverter/chargers. Unless Victron’s certification efforts are ahead of their documentation, the only options for these that satisfy the ABYC’s requirements (e.g. UL 458 for inverters and inverter/chargers) are a small selection of MultiPlus and MultiPlus-II inverter/chargers that include only models with 120VAC output, no more than 3000VA rating, and only 12V or 24V.
Of course, bigger systems can be built using the options to combine multiple inverter/chargers, and 230/240V can be achieved in a couple of different ways, but an insurable, ABYC-compliant, DVCC-capable system that includes an inverter running on 48V batteries does not appear to be possible at this time.
I still really like Victron gear and the parallel redundancy capability of the BMSs in particular, but potential users who want an ABYC-compliant system should be aware that their options are very limited and designing such a system requires careful reading of the ABYC standards and Victron’s documentation and certification statements.