Paralleling Lynx Smart BMSes and MPPT

Paralleling Lynx Smart BMSes: two Lynx Smart BMS 1000 and two SmartSolar MPPT 150-70-Tr VE Can.

A) If you connect the 4 components to a single VE.Can port of CERBO GX, the two MPPTs are probably seen together, but if one of the BMS stops, the VE.Can BUS is probably interrupted and both MPPTs disappear. RIGHT OR WRONG ???

B) If you connect a BMS and an MPPT to a VE.Can port of CERBO GX and the other BMS plus MPPT pair to the other VE.Can port of CERBO GX, if one of the two BMS stops, the other continues to function, keeping the corresponding MTTP in operation. RIGHT OR WRONG ???

It is not clear, in case (B), if when all four components are working, the MPPTs are seen as a single object. WHAT HAPPENS ???

thanks a lot.

I forwarded my question to technical support. Probably since I am in DIY I will not receive an answer from anyone. The question was about “Paralleling Lynx Smart BMSes: two Lynx Smart BMS 1000 and two SmartSolar MPPT 150-70-Tr VE Can” and related to the use of one or two CERBO CAN ports in this configuration. Can I change from DIY to something else? Thanks.

— Moved to Q&A by Guy ----

Hi @ERU,

VE.Can is a bus topology network; the two VE.Can ports are connected internally, and passively, and don’t require the device itself to be working for the VE.Can network to continue “through” their VE.Can ports.

If the single daisy chained VE.Can cable itself is interrupted or damaged, then the network is affected though. So the answer really depends on the specific type of fault.

Using one port or the other doesn’t make much difference.

The VE.Can network is designed to be very failsafe redundant when there is parallel Lynx Smart BMS connected. This is its main feature!

When the system detects 2 Lynx Smart BMS in parallel, it creates a third ‘virtual’ BMS that takes the values and control signals of the 2, and then uses the virtual BMS as the primary master to control the other devices.

If one of the 2 Lynx Smart BMS fails, then the system falls back to the single remaining one without interruption and controls what it can. Depending on the nature of the failure, this might mean seamless continuity of the VE.Can network through the failed BMS (it failed internally), or not (if the network cable is broken off or physically disconnected).

If the network cable is interrupted, then the network segments will do their best to persist. So you might find some advantage to pairing an MPPT with a Lynx BMS on one side of the VE.Can Bus, and another MPPT with Lynx BMS on the other side, with the GX device in the middle.

As for the MPPTs being seen as a single object, that isn’t really how it works either. Some values from multiple MPPTs are collated together, such as solar production so there is a single figure on the GX touch display. But the MPPTs still retain their individual identity on the GX with their individual solar production readings, firmware versions, serial numbers, etc and all that is still visible on both the GX device and the VRM Portal regardless of how many are connected together, or how they are positioned on the VE.Can bus.

Hi GUY,
Really complete and exhaustive answer that clarifies all my doubts on the two questions I asked. Furthermore, the description of the “Virtual BMS” that ALSO acquires the control signals of the two BMS explains the statement in the manuals that it is sufficient to send them “physically” to one of the two BMS … a statement that until now I had accepted as a “mystery of faith”.
THANK YOU, THANK YOU, THANK YOU.
When will we have a nice tutorial on the subject of multiple BMS and devices that can be connected to them?

This topic was automatically closed 14 days after the last reply. New replies are no longer allowed.