Seplos BMS

Guys, ok so I pulled the 280L apart again and after top balancing the two new cells for a week or so put it back together and added the Neey for a week before I connected it with the Seplos V4 to the inverter yesterday.

It semed ok until I started to dump the access energy at 10pm last night to drop it back to 10% soc before 2am.

By 12am one of the cells in it cell 11 (replacement cell) (bat 2) just fell through through the floor and hence the battery stopped discharging a consequence of this is the soc changes (only one battery now) and hence the discharge current is too large to reach the 2am EV window without importing from the grid.

As I was still awake I just killed the discharge.

Cells this morning SOC @95%.

cell 11 & 12 these are the "new" cells from Fogstar.

The existing cells are EVE (not sure what grade), Fogstar didn't have any of these so I bought a couple of these?

Straight out of the box they were 3.29V and barely made it to 3.31V after a weeks charging with the bench charger.

Couple questions, can you sucessfully mix different manufacturers cells, and should these have balanced out with the Neey by now and be following the rest of the pack?

Should I bare with it or are they just naff cells and try to get some new EVE cells?

Thanks

Hi, yes looks good to me hook it up to the inverter and let it start earning money, out of curiosity how long was long for the top balance and did you connect all the cells in parallel with bus bars and charge at 3.65v 10a?

The alarms will clear once you start using it, give it a couple of charges and discharges with the inverter and see how it goes.

I think cell high is 3.5v and bat high is 55v, most setting on the Seplos can be changed but generally especially with the V4 with the active JK balancer other than the capacity it should work fine.

You do need to blue tooth to the JK balancer and set one parameter on that

https://cdn.shopify.com/s/files/1/1347/0997/files/JK_Balancer_Upgrade_1.pdf?v=1750082480

Thanks graememk, so leave it connected even though it keeps going into standby? I've changed the settings on the Seplos now so its no longer trying to balance.

Ok, so I have set the COVP to 3.55v, I think the charge fet is active once either the Batt over volt recovery or Cell high recovery are reached could be both or either not sure?

Would there be any benefit in pulling the front of it and connecting the bench charger to the offending cells one at a time or is not possible to charge individual cell at same time as charging the pack?

Thanks graememk.

So I've made some changes and can get it to standby/charge every 20mins or so, but looking at it this morning it to me looks like very little is happening, I would have expected the minimum cell to creep up to the max cell?

The Neey is doing what it should taking current from the high cells and adding it to the low cells, but the low cells seem to just be sat there not increasing in voltage at all.

Should I just leave it at it or strip and top balance all the cells?

I've turned the rectifier off now.

What do you suggest?

Thanks graememk, rectifier back on will leave alone.