question

Have you read the manual for the Smart BMS 12-200?

The BMS is designed to limit the charge current from a 12v alternator via the fuse between the alternator input and the device, thus the use of a DC/DC is not needed. I have not used on so have no idea how well it will work with a Euro5 Alternator.

Some example install topologies can be found in the manual here.

have a good read of the manual.

Thank you for the information. This has been a 3 year covid project so one or two manuals have been consumed. As you say the Smart BMS 12-200 will work fine on a standard alternator output. The Euro5 smart alternator will not supply a constant voltage above the Smart BMS 12-200's minimum start charging voltage of >13 V. The smart alternator ECU in the Euro5 engine monitors the lead acid vehicle battery voltage and when believes it is fully charged (circa 12.9 V) drops the alternator output below the BMV's requirement of >13V. By monitoring my currently installed system the smart alternator will supply a maximum of 20A periodically during the first 1/2 hour of driving and will the cut the alternator voltage below the threshold and the lithium charging stops.

Hence the requirement for some form of ensuring a constant charge voltage above 13V from the smart alternator, which is what the Buck-Boost 50 or Orion-Tr Smart DC-DC converters are designed for.

My concern is that I have been told by one supplier that the Smart BMS 12-200 MUST use an isolated Orion-Tr Smart DC-DC whereas another states that this is not necessary and a non-isolated Orion-Tr Smart DC-DC would suffice.

So clarification of this is paramount before the final installation and I would also like to ensure whether the Buck-Boost 50 will work as I cannot currently clarify this has so far I can not find a schematic of any of these combinations. (Nice to clarify 100% if the Buck-Boost 50 will do the job as that is currently on it's way from Europe. I got cold feet prior to it's arrival and wanted to clarify I did not buy the optimum solution)

EDIT: I made a rather glaring mistake and it is not the using positive based Smart BMS 12/200 but the older non-Smart negative based BMS 12/200. (Rookie mistake?? Sorry)

Hello desswood, After nearly one year since you posted your question did you make a choice and if yes which option was yours?

Are you satisfy with your decision if you used it for a while?

Regards