Seplos CAN BUS RS485 48v 200A 8S-16S BMS

[Mariner62]

It's been running for a few months charging at night up to 100%. That's why I want to check settings to make sure nothing is wrong or incorrect

What has been the lowest SOC over the months you have been running?
Did you previously go down much lower or has this 24% lower limit alarm been a regular thing since commissioning?

As @brum mentioned, you need a proper full charge and top balance to happen.
I would suggest that you run the logging tool in the SEPLOS software and capture the data for the hours it takes to charge up completely, then create some graphs from that to see for sure what is happening.

 

[testtenor]

What has been the lowest SOC over the months you have been running?
Did you previously go down much lower or has this 24% lower limit alarm been a regular thing since commissioning?

As @brum mentioned, you need a proper full charge and top balance to happen.
I would suggest that you run the logging tool in the SEPLOS software and capture the data for the hours it takes to charge up completely, then create some graphs from that to see for sure what is happening.

No it's been down to 15%. This is why I am just flagging it now, as it's a new thing

 

[Mariner62]

No it's been down to 15%. This is why I am just flagging it now, as it's a new thing

Right. It could just be a single rogue cell which is hitting the upper kneepoint early on the charge cycle. Get the data logged and have a look or post the file here.

 

[brum]

I suppose it won't work just by pulling out the cable. The inverter will require a configuration change.

You may try an alternative approach directly to the BMS.

Option 1) Set the Ah capacity of the battery to a high value. Instead of 280Ah to 400Ah. This will prevent the BMS from stating that the batteries are charged at the old level and will lead to charging until the high voltage disconnect alarm pops up. The BMS will calibrate the 100% SOC point. Once the battery goes to low voltage disconnect this will calibrate the 0% SOC.

Option 2) Likely won't work, but you can try to set the SOC level when the battery is at 2.8/3V per cell. Set it to 1% and if you see that value on the display of the BMS you are good to go. It didn't work for me - the specified SOC value in the settings had no effect on the actual SOC that the BMS was calculating.

 

[CrossStreet]

If the BMS cuts off on a SoC threshold, disable that in the checkboxes session of Upload Parameters. I did that.

 

[brum]

More likely if the inverter cuts off on a SOC threshold. The Seplos BMS will cut on voltage levels only as far as I have seen.

 

[testtenor]

More likely if the inverter cuts off on a SOC threshold. The Seplos BMS will cut on voltage levels only as far as I have seen.

So do you think it's worth trying @brums idea and setting it to 300ah+? Tricking both the BMS and the inverter to fully charge?

 

[brum]

Are you asking me if my idea is worth trying? It looks like a simple and cheap approach to trick the system into fully charging the battery.

 

[CrossStreet]

My toggle is simply easier, but the other method should work too.

 

[testtenor]

My toggle is simply easier, but the other method should work too.

Which function is it? I can't see it specifically.

 

[CrossStreet]

I can only check that in the evening, but it was a toggle near the bottom, with "SoC" in the name. Also use BatteryMonitor V2.1.9 just in case.

 

[testtenor]

I can only check that in the evening, but it was a toggle near the bottom, with "SoC" in the name. Also use BatteryMonitor V2.1.9 just in case.

Ah. I'm not sure I can use 2.1.9 let me check. I'm logged in on 2.1.8 at the moment

 

[testtenor]

Yes I can log on 2.1.9

 

[CrossStreet]

Not the very bottom then

 

[testtenor]

Not the very bottom then

Nothing that says SoC. There is a "remaining capacity protection" toggle

 

[CrossStreet]

These toggles. They dont have "SoC" in the name after all.

 

[testtenor]

These toggles. They dont have "SoC" in the name after allView attachment 131704.

Toggle them off?

 

[CrossStreet]

Yes

 

[testtenor]

Yes

Ok. I'll give it a go this evening when the battery is charging

 

[Mariner62]

I would recommend that you don't fiddle around with any of those settings until you've done a real-time recording of the cell data during an attempted charge cycle. Then you can determine exactly why the problem occurs. At the moment I fear you are in the dark clutching at straws.