I’m currently getting quotes for home solar and battery systems. One that seems quite well priced is Duracell’s Dura5 battery. Having to rely on cloud servers is a deal breaker for me, and my Googling has only turned up getting Home Assistant to interface with this battery by doing RESTful stuff with Duracell’s cloud.
However, the spec sheet says that the Dura5 battery has CAN / RS485 communication ports, so is it possible to get Home Assistant to control this kit locally?
For hybrid inverters and batteries, you cannot control the battery, only the inverter.
Batteries talk to inverters, usually over CANbus. You need to connect to the inverter, which is possibly a Dura-i device.
This appears to have the usual CAN and RS485 ports to connect to the battery and to the CT clamp meter. Extra RS485 port may offer Modbus RTU, and if there is indeed Ethernet (optional LAN/WiFi dongle) then Modbus over TCP may also be offered. Like many manufacturers today, monitoring and control is offered over a cloud based app, and other access can be limited.
Actually doing anything with Modbus by direct connection to the inverter requires knowing the correct settings, protocol, and registers, which are often not willingly offered. However, many devices are actually badged products / systems from the mainstream manufacturers, and will use or mimic something like Solis, Deye, Sunsynk, or Growatt. This can mean that, with a bit of tinkering, an existing HA integration for another brand could work. Of course, unless someone else has already taken this step, with a newly introduced and small market device, you may find yourself being the first person to try and connect to this particular model.
If open Modbus communication is offered (RTU or TCP) by the inverter, and if physical connection can be made, and if the register map used is fairly similar to eg Solis, and if the inverter data and control commands are fairly standard, then I would suggest possibly yes with time and effort.
Interestingly, I had an installer quote the other day for Duracell batteries paired with a Solis inverter (because he said the Duracell inverters are crap), so that may be an option. Although that installer also swore blind that there are no products on the market that can do whole home backup, so I question his knowledge a bit!