RikusW

Just saw this today, https://www.4-noks.com/shop/elios4you-accessories/power-reducer/?lang=en was considering building something like this, I'm guessing inside is something similar to https://www.researchgate.net/figure/Standard-ac-ac-buck-converter_fig12_224125119

The Growatt manual recommend USE 2 for lithium voltage based setup, equalization needs to be disabled.. The lithium protocol for Pylontech is L52 for the CAN connection, you also need a 120 Ohm terminator on the unused CAN connector on the battery.

The protocol also change immediately when changing the dip switches, no need to power cycle the battery. Something to be aware of if something accidentally bumps the switch and it goes to Victron 250 the inverter might switch off, I haven't tested this, maybe Growatt will autodetect bit rate change, also if the cable is disconnected the inverter will switch off.

The Axpert diagrams come with the user manuals.

PS, I'd also like to know how to connect the comms cable and if any settings needs to be done for the protocol like for example Growatt.

Hi I've set up the settings for a voltage based installation without comms cable for 2x Mecer Axpert mkII in parallel and 3x Pylontech US3000, the electrician didn't set the right settings, voltages/current was too high and batteries started to smell strange, still working now a few years later fortunately. The settings are 5=USE then 1,2,11,12,13,16,26,27,29 needs to be set, refer to the battery and inverter manuals. It might be necessary to add the cable voltage drop to the charging voltage, it might be a few hundred mV. RS485-protocol-pylon-low-voltage-V3.3-20180821.pdfPYLON LFP Battery communication protocol - RS232 V2.8 20161216.pdfCAN-Bus-protocol-PYLON-low-voltage-V1.2-20180408.pdf Regards Rikus

Check setting 14, CSO/SNU/OSO, SNU sounds like what you want ? and then limit the AC charge current.

In User 2 mode voltage based setup it stops charging once the bulk voltage is reached, no constant voltage charge, then restarts charging multiple times throughout the day and once solar output is low enough not to reach the bulk voltage remain charging until the end of the day.

I set the battery protocol to Goodwe and got the following from the CAN bus, this looks like Pylontech in the above document and is slightly different from the Victron 250kbps/500kbps protocol. (listed above from a previous protocol capture) Growatt to protocol L52 is for Pylontech so seems like Goodwe would be the right setting. 0000305 01 02 03 04 05 06 07 08 -- sent from inverter 0000351 22 02 f4 01 e8 03 d6 01 0000355 63 00 64 00 ac 26 0000356 2d 15 00 00 e0 00 0000359 00 00 00 00 -- not in Victron which gives 35a instead 000035c c0 -- not in Victron 000035e 42 6c 75 65 4e 6f 76 61 000035f 00 00 00 05 0000370 42 6c 75 65 4e 6f 76 61 0000211 ff ff ff ff ff ff ff ff

Seems like the Bluenova never reaches 100% SoC but stays at 99%, the inverter then continues charging at around 2A or more spiking up to 240W

BlueNova BN52V-100-5.2k-DU CAN dump - Victron 250 dip switch setting - 250kbps 849 0000351 - 22 02 f4 01 e8 03 d6 01 - BmsLimits 0222 - 54.6 V charge voltage 01f4 - 50.0 A charge current max 03e8 - 100.0 A discharge current max 01d6 - 47.0 V discharge voltage min 853 0000355 - 5e 00 64 00 b8 24 - BmsSoc 005e - 94 % SoC 0064 - 100 % SoH 24b8 - 94.00 % SoC 854 0000356 - b6 14 c4 ff d5 00 - Battery status 14b6 - 53.02 V ffc4 - -6.0 A 00d5 - 21.3 C 858 000035a - a8 aa 02 02 20 80 02 02 - BmsAlarm ??? Vector dbc format https://www.csselectronics.com/pages/can-dbc-file-database-intro VAL_TABLE_ AlarmWarningValues 3 "Not Supported" 2 "InActive" 1 "Active" 0 "Not Supported" ; 2 SG_ BMS_Alarm_OverVoltage : 2|2@1+ (1,0) [0|3] "" Vector__XXX 2 SG_ BMS_Alarm_UnderVoltage : 4|2@1+ (1,0) [0|3] "" Vector__XXX 2 SG_ BMS_Alarm_OverTemp : 6|2@1+ (1,0) [0|3] "" Vector__XXX 2 SG_ BMS_Alarm_UnderTemp : 8|2@1+ (1,0) [0|3] "" Vector__XXX 0 SG_ BMS_Alarm_BmsComms : 22|2@1+ (1,0) [0|3] "" Vector__XXX 2 SG_ BMS_Alarm_CellGap : 24|2@1+ (1,0) [0|3] "" Vector__XXX 0 SG_ BMS_Warning_OverVoltage : 34|2@1+ (1,0) [0|3] "" Vector__XXX 2 SG_ BMS_Warning_UnderVoltage : 36|2@1+ (1,0) [0|3] "" Vector__XXX 2 SG_ BMS_Warning_OverTemp : 38|2@1+ (1,0) [0|3] "" Vector__XXX 0 SG_ BMS_Warning_UnderTemp : 40|2@1+ (1,0) [0|3] "" Vector__XXX 2 SG_ BMS_Warning_BmsComms : 54|2@1+ (1,0) [0|3] "" Vector__XXX 2 SG_ BMS_Warning_CellGap : 56|2@1+ (1,0) [0|3] "" Vector__XXX ??? 862 000035e - 42 6c 75 65 4e 6f 76 61 - Manufacturer = BlueNova 863 000035f - 00 00 00 05 ? 880 0000370 - 42 6c 75 65 4e 6f 76 61 - BmsName = BlueNova 888 0000378 - 3a 07 00 00 e7 06 00 00 ? 889 0000379 - 64 00 ? 882 0000372 - ff ff ff ff ff ff ff ff - BmsInfo 883 0000373 - eb 0c f6 0c 26 01 28 01 0ceb 3307 mV * 16 = 52.912 V Low Cell 0cf6 3318 mV * 16 = 53.088 V High Cell 0126 294 - 273 = 21 C Low temp 0128 296 - 273 = 23 C High temp 529 0000211 - ff ff ff ff ff ff ff ff ? 0000351 - 22 02 f4 01 e8 03 d6 01 0000355 - 5e 00 64 00 b8 24 0000356 - b5 14 c3 ff d5 00 --> 53.01 V -6.1 A 21.3 C 000035a - a8 aa 02 02 20 80 02 02 000035e - 42 6c 75 65 4e 6f 76 61 000035f - 00 00 00 05 0000370 - 42 6c 75 65 4e 6f 76 61 0000378 - 3a 07 00 00 e7 06 00 00 0000379 - 64 00 0000372 - ff ff ff ff ff ff ff ff 0000373 - e8 0c f6 0c 26 01 28 01 0000211 - ff ff ff ff ff ff ff ff

https://www.bobali24.de/bobali_files/photovoltaik/estg/pdf/The list of compatibility between battery and Growatt Off-grid Inverter 2020.06 V1.4.pdfThe list of compatibility between battery and Growatt Off-grid Inverter 2020.06 V1.4.pdf

I just managed to get the BMS CAN connection working for Growatt-SPF5000-ES and BN52V-100-5.2k-DU. Now Settings 12,13 and 21 is in SoC % I connected an oscilloscope to the CAN port on the BlueNova and saw the bitrate being 250k then connected a CAN tap I built for work to the port and got a protocol dump which looked very similar to the Pylontech CAN protocol. Guessing the Victron 250 was for the bitrate the Victron 500 setting would be 500k which is what Pylontech runs at. It works after setting the Growatt to protocol L52. Settings: Victron 500 on the battery, protocol L52 on the inverter. (edit: Use Goodwe instead it is more similar to Pylontech, see below) I made 120 Ohm termination plug for the battery's second CAN port, but can be bought for R80 for two. Pinout: CAN-H battery = 7 inverter = 4 CAN-L battery = 8 inverter = 5 Just the two wires no other connections made on the RJ45 plugs

We used https://solar-assistant.io/ and then tuned the battery voltages until it reached 100 SoC, works well enough now without a BMS cable, but I'll try to develop a Pylontech emulator to connect the solar assistant info to the inverter, at least there are some documentation for that protocol. Battery type User 2 Charger source priority Solar first Back to battery voltage 51.0 V (not tuned yet but works) To grid battery voltage 49.0 V (not tuned yet but works) Shutdown battery voltage 46.5 V Battery float charge voltage 55 V There are a 0.4V drop over the cables at 30A , so 55.1V+cable drop of your installation, we have 1m of 35mm2 Battery bulk charge voltage 55 V (previously I used 55.5V, then 55.4V but 55V seems to work just as well since charge is 54.6V) Max charge current 30.0 A Max AC charge current 20.0 A