Currently I have a Pylontech home battery system connected to a Victron 3-phase ESS with Cerbo GX using the CAN-Bus connection 1. Question: can I connect a second battery with Seplos V3 or V4 to the CAN-bus connection 2 on the Cerbo GX without conflict? Will I see this new system separately in VRM?
No sure how it works using Pylontech, I don’t have experience with this battery. But as comparison, maybe it helps, the JK-BMS have their own connection between multiple batteries and there is only one CAN cable going to the Cerbo. And both batteries are than visible in the Cerbo system. Again, not sure if this helps you on the Pylontech.
Thank you Rene, on CAN-bus 1, I have a string of 4 x Pylontech US5000 units, all of which I can monitor individually. The question was whether I can also connect a string on CAN-bus 2, but now with 4 x Seplos V3 or V4 BMS units. I assume that ports 1 and 2 are internally interconnected within the Cerbo GX (forming one bus).
Venus OS is not yet ready for use with different BMS’es. They’ve just released support for multiple of their own NG BMSés on one Venus device.
I’m sure they’re working on making this possible for mixed brands.
BUT! Pylonthech cases have 15 cells in series, so make sure your boxes with the Seplos BMS are also built with 15 cells, not 16! You will either overcharge your Pylontech, or never fully charge and balance your other box.
Thank you David for the tip!
US5000 is 48V and 100Ah = 4.8 kWh
The Pylontech has a master what is doing the aggregation of its slaves. Pylon slave connections are propieretary why adding a Seplos will not work. Even not if you use any of the LV hubs.
The correct approach to run diffrent BMS is to add own CAN interface for each system. The slaves within one CAN bus of same manufacturer are aggregated by the master. To aggregate diffrent CAN bus systems, you need to install one of the many available open source aggregators.
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Thank you, Janvi, for your reply. However, that will not solve David’s problem regarding the voltage difference between the 15-cell and 16-cell battery combinations. A possible solution might be splitting the system: using a MultiPlus for L1 with the Pylontech batteries, and the other two Multiplus for L2 & L3 with the SEPLOS batteries. This would require two distributors, two Cerbo GX units, and an additional energy meter.
I can skip this extra energy meter by :
- One larger system for L2&L3 with SEPLOS + full DESS
- Keep L1 as a simple ESS system with Pylontech
- This might be more cost-effective than full dual-DESS setup
I have already two distributors, slitting is no problem. Only cost is an aditional Cerbo (Raspberry pi).
15s is a prerequisite for Pylons. Should be supported by Seplos as well. My self made extension chassis are 8+7 cells what you see at the diffrent length of the fireboard covers. In front is a NH00 fuse to connect cell 8+9. Any change to 16s would require to trash all the Pylons.
Thank you, JanVi. Your suggestion to use the DCSystemAggregator for the CAN bus connection, along with a Seplos Smart BMS 200A/250A (CAN+UART+BT) configured for 15 cells, perfectly solves my problem.