Seplos BMS

220 USD currently on Alibaba with all fees. Not sure if that is currently a good price.

Did you print the legs yourself or buy them somewhere?

Howdy all. I'm having an issue with my (new to me) Seplos bms + 200Ah of LiFePo4 cells (16) + ME3000SP.

Everything is wired correctly afaik.

When I power on the battery and start the BMS, after the BMS has initialised the inverter will flash on briefly and the SOC leds on the BMS will light up. Then it all goes dark, except the flashing led on the BMS. I think this is correct behaviour.

Then when I turn on the mains to the inverter it goes through the startup procedure (Wait 60s...) and eventually it will settle at Check Discharge (or Check Charge if I've excess solar). It never moves past that. The BMS seems to stay in standby (flashing led, no SOC leds).

The inverter came with sw version 2.5 and I've just updated it to 3.06 in case that was the issue, but it made no difference. It's set to Time-of-Use mode.

The fact that everything seems to work for a second or two when I turn on the battery (before I turn on the mains) leads me to think I may have configured something incorrectly, however the only thing I changed in the BMS configuration was battery capacity (from 100 to 200Ah) and SOC (from 50Ah to 198Ah (I top balanced the cells in advance), although for some reason the BMS still says 24.9% SOC).

Anyone come across this before, or any suggestions for things to try?

Yes. So you'll need to add manual parameters, which will lead to it calculating the SOC% itself - which is is useless at doing.

Reach out to Sofar about getting the temperature sensor. I remember you absolutely need it, but I couldn't remember the implications of not having one

No errors or warnings. No red leds. Everything looks fine to me (though I've never seen this setup before). Just BMS in standby, flashing away, and inverter looking like it's going to do something, but just sits there saying Check Discharge with the discharge led flashing. I think it does this as a final step before starting discharging?

Is the 25% soc holding it out? What setting have you in for lower limit. In the settings page you can put in an updated soc value as well

That occurred to me. I have set the inverter to 90% DOD to see if it'd make any difference, but nope

Ok I take it back. For some reason it has started working and is currently discharging.

No surprise there although the ME3000SP has a will of its own too 😂

Had a look at my mate's Seplos this evening and it showed battery as 100% SOC when it was at 53V. That's just wrong. It looks like he is exporting when he shouldn't have to and importing when he shouldn't have to either. Cells are also well out of balance (but weren't top balanced when recently upgraded). Seplos is incapable of even starting to address that

Can't wait to upgrade him to the Sunsynk inverter (from a 4G Solis that can only do 60A) plus JK BMS with active balancing. And then let the inverter do its job based on voltages. Not based on what a cheap and nasty BMS (not just Seplos - pointing the finger at all cheap BMS here) wrongly thinks is the SOC

And don't get me wrong, it is what it is, only a fool would spend €3k on batteries and then another €3k on a decent BMS. We have to make do with cheap ones that will protect the battery alright, but are pretty sh1t at everything else

You should only need to change the capacity

Would anyone be able to put up their parameter/config file? Just to compare to my own. Soooo many variables.

I can see some differences all right, 0.1v of an increase in alarms basically.

couple of weird ones:

<Name>SOC</Name> = 100

I've 75??

<Name>BitGroup5</Name> = 91

I've 9F??

Anyone have any issues with the seplos randomly shutting off itself?