Off peak grid tied storage with ac coupled inverter

MisterB1959 said:

@Gareth79


Is the Seplos BMS the only BMS that will work with the Sofar inverter and home made battery bank, or has anyone else used a different bms with success?

i assume the Seplos BMS is used by pylontech batteries, so it's easier to configure?

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CrossStreet said:

I bought a 200a 16s Seplos, which I am planning to connect to the 8kW Deye inverter. Reading this forum this should be possible (and there is a diagram in one post).

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Gareth79 said:

So an update - the system is mostly set up and working ok!

The Seplos BMS is working well. The only real issue I had was that my sytem is set up in 2x packs and the link cable between them was too long, and causing a higher voltage on the first cell of the second pack. I rewired the pack (flipped the busbars) so that the cells linked at at the front, and switched the 25mm cable for 50mm, and now it works perfectly.

The ME3000SP is very good too, the KEY thing when setting one up is to "freeze" the CT direction. I didn't with mine, and it all worked ok when the solar exported it detected it as a load and tried to export to match it!

I am using Home Assistant and have the Seplos BMS linked in using ESPHome. The ME3000SP didn't have any ESPHome integration but I am writing a Modbus configuration to monitor and control it (currently a WIP). There is an MQTT bridge for it, but I try and use ESPHome wherever possible. Then it will be possible to directly control the charging/discharging from Home Assistant, eg. as a timer, and also shut it off before a full charge based on solar predictions for the following day.

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cajocars said:

I'm doing a very similar project to yours (I'm on Octopus Go) and I've just bought 16x EVE 280Ah cells and a JBD bms; I just need to buy the inverter (or AC charger) and I was thinking about the Sofar ME3000SP; am I right it can work even without communicating with the BMS (mine doesn't have an RS485 port)? And what do you need to do to communicate/control it with Home Assistant?

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Gareth79 said:

The M3000SP can be used without a BMS, but I believe you need to run it in lead-acid mode and manually set the various parameters, there are guides online. This is a very inferior setup to having a BMS with CAN/RS485 though, and others have mentioned that it's a bit of a pain to manage. With the Seplos you just plug it in and the inverter defers almost all control to the BMS, there's nothing to configure except the work mode (eg. when you want to charge, what maximum power and to what SOC %). I bought a Daly and then sold it on when I realised it wouldn't be great.

For HA sofar2mqtt is what most people use I think. I am still working on my ESPHome configuration, I haven't hurried because right now with winter sun there's no need to shut off charging early!

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cajocars said:

I’ve ordered the ME3000SP
So if I run it in lead-acid mode, would it estimate SOC based on pure voltage?

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