I’m a farmer planning to build a high‑voltage LiFePO₄ ESS (~120 kWh, ~120S) using EVE MB31 (314 Ah) cells.
The main inverter will be a Deye SUN‑30K‑SG02HP3‑EU‑AM3, used for storing PV energy and running farm loads.
I’m considering a Batrium Watchmon‑based BMS and would like to confirm suitability and real‑world experience.
Questions:
Has anyone successfully used **Batrium with a Deye SUN‑30K / 50K HV inverter?
Are there any known limitations regarding **SOC or charge/discharge limit communication?
Is the balancing capability of Batrium CellMate modules sufficient for large 314 Ah LFP cells in a ~120S configuration?
In the future, I also plan to power a Nissan Leaf (EM57) motor and inverter from the same HV battery to drive an electric feed mixer (separate operating mode, no regeneration).
Any feedback or experience would be greatly appreciated before I commit to hardware.
Hi Johan,
I have a similar setup.
Sunsynk 50kW inverter that was initially paired with 96 280Ah batteries. I have now added another 48 305Ah batteries all controlled by Batrium watchmoncore and 9 cellmate K9’s.
The initial balancing was speeded up by discharging some cells with a 300w wire wound resistor pack and boosting some cells with a 300w power supply.
Even though the cells are different capacities the batrium maintains the top balance really well but obviously the overall capacity is limited by the 280Ah cells.
We have had some reports that the firmware on DEYE inverters is a bit unreliable, the Sunsynk that ken mentions is the same hardware, just different firmware and branding.
Another good option for large HV inverters is the GoodWe ET series.
K9s are perfectly capable of balancing 300 or even 600 Ah cells, but it is important to mount fans on them or point a pedestal fan at them when doing your first balance. This will give much better performance.
Good to hear that Watchmon Core + CellMate K9s are no problem with large cells(your screen looks nice!). That answers my question for the 314Ah MB31 cells. I’ll make sure there is good airflow for the K9s.
About the inverters: Sunsynk is quite hard to get here in the EU, and that also makes it less comparable for me. The concern there is mainly availability and fast replacement if something ever fails, which is important for me. The GoodWe ET series sounds interesting, I wasn’t looking at those yet but I’ll definitely dive deeper into that option.
That said, I’m still trying to understand if Deye is really a no‑go, or more a case of “works fine but firmware needs attention”. I like programming and testing stuff, but the goal is that the bms controls the inverter. Problems when battery is full, but Deye kept charging I’ve heard. I’m running a 48V Deye system also with 314ah cells already and that one has been solid so far, which makes me a bit hesitant to rule Deye out completely for HV.
It is important to note that the Goodwe ET series cannot accept any energy from the backup side at all and will go into an error state (no battery charging from the backup side / using additional inverters or micro-inverters in off-grid mode is not possible). This is the main reason why I would have to switch from my Goodwe GW8k-ET to the Sungrow SH10RT-20.
What I mean by this is: The ET can only charge the battery via the grid connection (other AC-coupled inverters) and its own PV inputs (solar power), but not via the backup output (emergency power network).
In island mode, the backup port of the ET series – as I have read in forums and tested with my GoodWe GW8K-ET – is truly only an output. In off-grid state, the grid is disconnected from the backup port via a relay.
If there is an energy surplus at the backup output, the ET restarts or goes into an error state. I had tried physically bridging the grid side with the backup side back then, which also did not succeed.
With Sungrow and Deye (according to my internet research), the backup port can function as both an input and output, and the battery can be both discharged and charged via the backup AC port.
Hello to all, i have an deye sun 25k sg01hp3 eu am2 25kw (high voltage), now my can connection doesnt work to the watchmon core. is here anyone who connect the same setup and can help with the right parameters. In the batrium is no pylontech HV .
Hi Johan,
Solis S6 30kW hybrid looks like it has similar performance and flexible programing to the Sunsynk.
I have several Solis non-hybrid inverters on site and they are proving to be very reliable.
Not sure if there are any native Solis protocols in the batrium software but if I got the Sunsynk to communicate then I am sure the Solis can too.
Hello James, i did it two times trough the wizzard, there is no tx and no rx. when i use other profiles it show tx and rx on the right side up. but it doesnt count. they do not understand each other. In moment i have physically an solar system but buy diesel for the perkins to run my needs. becouse of the missing CAN communication.
Did you try BYD ESS (Reserved 40) and are you restarting your inverter after running the wizard, and configuring the inverter for a BYD HVS battery? We have other customers that have managed to get it working with that profile:
Hello James, i have the SUN-25K-SG01HP3-EU-AM2 and i tryed the reserved 40 with the 00,01,02 in the deye, with restart all the time. no way. all the time red light. but with 40 is running tx from batrium with 33 run nothing.
i found the mistake, the can bus ground was wrong conected. now i am more educated to mesure the can out. so this will not hapen again. I am very apologize for your time. sorry. Now i have just somtimes an mistake with the communication, will charge today and see if i can fix the problem. In moment i use reserved 33 with 00 in Deye but after i want to try 40 with 02. will keep you informed how its going on.
