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Deye inverter seplos 11kwh DIY battery capacity first run

Chris_S

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Feb 28, 2023
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South Africa
Getting ready to calibrate the capacity on a 200A seplos BMS.
How am I going to set my inverter to reach bms cutoff?
Do I set shutdown on the inverter to 0%?
 
Is this LifePO4 batteries? Then set them to 15-20% or try 3.13-3.15V per cell as your cutoff if using volts.
I am using 3.13V per cell myself atm.
 
just to be sure, first is only full charge till cutoff ( make sure your cells are top balanced before doing this !)

then a full discharge only till cut off
 
just to be sure, first is only full charge till cutoff ( make sure your cells are top balanced before doing this !)

then a full discharge only till cut off
I'm going to do it in this order.
1. Top balance to 3.65
2. Assemble battery and bms connect up to inverter(no CAN cable at first.
3. Set inverter to agm and charge to 58.5 so bms cuts off at 3.65b.
4. Turn off PV and utility and discharge to 38.8 so bms cuts off at 2.5v
5. Charge up pack a little. Connect CAN cable and change battery settings to lithium with appropriate normal operating voltage ranges.
 
I'm going to do it in this order.
1. Top balance to 3.65
2. Assemble battery and bms connect up to inverter(no CAN cable at first.
3. Set inverter to agm and charge to 58.5 so bms cuts off at 3.65b.
4. Turn off PV and utility and discharge to 38.8 so bms cuts off at 2.5v
5. Charge up pack a little. Connect CAN cable and change battery settings to lithium with appropriate normal operating voltage ranges.
thats how i do it :)

possible difference to how i do it :
i put my cells in the enclosure, fixated

charge up my cells untill first cut off by bms
individually charge them to 3.65.
let them rest for 4 hours
start discharge

top balancing them as one big parallel battery simly takes too long
 
thats how i do it :)

possible difference to how i do it :
i put my cells in the enclosure, fixated

charge up my cells untill first cut off by bms
individually charge them to 3.65.
let them rest for 4 hours
start discharge

top balancing them as one big parallel battery simly takes too long
Hi. Seplos instructions say a full discharge at 0.5C for first run. Is 0.5C really that critical?

Also do you know the torque for the cable screws on the bms?

Thanks
 
Hi. Seplos instructions say a full discharge at 0.5C for first run. Is 0.5C really that critical?

Also do you know the torque for the cable screws on the bms?

Thanks
i try and stick to what they recommend, eventhough that is one long cycle to wait for while looking at that pretty battery

from the top of my head 6nm, but they released a build video stating the exact torques on yt
 
i try and stick to what they recommend, eventhough that is one long cycle to wait for while looking at that pretty battery

from the top of my head 6nm, but they released a build video stating the exact torques on yt
So 0.5C on a 230Ah pack will be 115A discharge? How many Watts is that on 220V?
 
depends on the losses in your system, but 100 amps on the 48v bus in my case eq about 5200 w..
btw if in europe, you're on 230v ;)
 
Another question. ?
Its fine to touch on a 50V DC system with bare hands right? Want to feel all the terminals for heat.
well, voltage can always kill you depending on circumstances..
if you make sure you dont complete the electrical circuit you should be fine, but anything over 24v ( or was it 12v ? ) has the potential to kill you, just keep that in mind

" great power , comes with great responsibility"
 
Last edited:
well, voltage can always kill you depending on circumstances..
if you make sure you dont complete the electrical circuit you should be fine, but anything over 24v ( or was it 12v ? ) has the potential to kill you, just keep that in mind

" great power , comes with great responsibility"
Hi can assist. I can't get communication via CAN from seplos BMS (no dips on) to sunsynk/deye 8kw inverter. I did the cable pins like you said before. Inverter is on lithium mode and CAN selected.
 
Hi can assist. I can't get communication via CAN from seplos BMS (no dips on) to sunsynk/deye 8kw inverter. I did the cable pins like you said before. Inverter is on lithium mode and CAN selected.
could you verify auto address and pooling is turned off in the bms ?

and verify you inserted the correct cable end in the bms and inverter ( if you used a premade cable and crimped and rj45 on there with 4-5-6 in there, that crimped connector should be in the Deye)
 
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