Gambit

I installed the latest versions for my batteries from the zip file on https://www.jendustries.co.za/sun-batt-lv and everything is running fine with my newest battery I added. I'm not sure if those are the absolute latest. I guess you could try mailing Herholdts and asking them. I think they are the local importers.

Hi @MarkRudling I was also having issues with an old usb to rs232 cable I had lying around. It was a bit pricey, but I bought this cable https://solar-assistant.io/shop/products/rs232_self and crimped the RJ45 on and it worked first time on all 3 of my Sunsynk batteries.

@WannabeSolarSparky Thanks for the advice. I managed to get all the BMS metrics from my 3 x Sunsynk 5.32 (SUN-BATT-5.32) batteries using a RS-485 transceiver on an ESP32 with ESPHome, but it turned out to be a bit of a mission to create the frankenstein RS485 cable to link all 3 batteries and the Sunsynk inverter. Unfortunately, you can't get the BMS metrics directly from the master battery like you can over RS232 (or I didn't find an easy way to do that) and instead have to setup an RS485 bus between all the batteries to connect to query each battery BMS directly. What makes it tricky with the Sunsynk batteries is that they use RJ45 sockets, which also share the CAN bus so I had to crimp a weird cable with 5 x RJ45 plugs and split off the CAN connection to the Inverter. Super happy it all worked first time but I'm wondering if there was an easier way to cable it all up. I now have a single ESP32 microcontroller powered by the inverter's 12V rail pulling metrics from 3 batteries and 1 inverter and pushing to Home Assistant.

I take my old batteries to my local Battery Centre and they give me cash for them.

I used the method discribed in the support pdf here https://support.sunsynk.com/support/solutions/articles/103000295813-how-to-request-a-firmware-upgrade-customers- . My inverter was upgraded about an hour afterwards.

Thanks for the advice. This was something I was thinking about doing, especially with a battery that hasn't been charged in such a long time. Was also thinking of dropping the charge amps down to 10amps to not stress it out.

Thanks @Virwat . That is good news, I hope the one I bought also has a similar SOC when I start it up.

I am a little worried, it is a long time since it has been charged. Going to install it on Friday. Hopefully it is fine and I don't have to send it back.

I was also curious about this and asked the AI. It looks like it was intended for people who have very strict meters that don't tolerate any export. The TLDR of the lengthy response was:

@slipx The battery was delivered today. Looks like it was manufactured 1 March 2023. So old stock :(

Thanks so much. I found this one a while back, but it is for the RS485 Modbus interface. Even though the Sunsynk batteries have RS485 ports, I was under the impression that the BMS metrics were only available over the RS232 interface on these batteries. I see there is a GitHub issue with more information on this, so I will have another look at this.

Thanks. Was also looking to go this route but was hoping to find an esphome external component. Was also contemplating writing my own.

@slipx what method/integration are you using to get the Sunsynk BMS cell metrics into HA?

Upgraded my 8 kW Sunsynk inverter firmware yesterday. Latest version is M 6.0.2.7 / S 0.7.1.7 / C E.4.3.D

AFAIK the Sunsynk batteries 5.32 batteries are rated 1C. I am also running an 8KW Sunsynk inverter with 2 x 5.32 KW Sunsynk batteries and the LiBMS menu shows 200A current limit which I think it gets from the battery BMS. 100A per battery