Daly BMS Wiring 16s 48v 250a

[Croqezgo]

I have built a 16s pack of Lifep04 batteries and I used my bench power supply to top balance them. All is well with that. However, I am unsure of how to wire the Daly BMS.

I see that the big B- goes to the battery pack negative. I understand the negative and balance wires.

1.) What do I hook the P- wire to? Is it the pack positive or some other place?

2.)Do I place the temperature probe into the pack between some cells?

3.) I have a shunt for a battery meter that goes to the negative battery terminal. Can I connect the B- cable to that? Reference the shunt https://www.amazon.com/QWORK-Battery.../dp/B08MWCYS74

4.) Can I connect my 48v to 12v dc converter to the B- and the Positive battery terminal?

5.) Where do the charger cables connect?

Edit: Or am I overthinking this all? It seems the P- basically just goes back to the shunt like the old battery cable did, then the BMS is just the inbetween brains on the negative side of everything.

Any help is appreciated.

[Pat911]

P-, or sometimes C- is both the charger negative and the cart supply negative. Positive is common so charger and cart positive go to the battery positive.

Temp probe should go between some cells,

The shunt will go either between the battery negative and the B- or P- and charger/loads.

12v reducer is just another load, so it gets connected to battery+ and P- or shunt, depending on where you have the shunt located.

Your thinking is correct, BMS just sits between the battery negative and everything else, B- to battery and P- to everything else.

Cheers
Pat

[Croqezgo]

Awesome! Thank you so much. I had figured that I was overthinking this. Pack is assembled and will test these out soon! These are supposed to be 1C continuous and 3C pulse discharge. If they are, and if the BMS can handle the load, this will be a huge improvement over the LA batteries!

[Pat911]

Which cells are you using? Let us know how you go.

[Croqezgo]

I am using Eve 230ah cells. However, I now have some questions regarding settings in the BMS. There are tons of settings, but I do not know what values to use. Any help is appreciated.

[Pat911]

Chg low temp protect = 0degC
Cell high volt protect = 3.65v
Cell low volt protect = 2.5v
Chg/disChg overcurrent = 230A - You may need to increase disChg as the Daly BMS is limited in its settings. Other BMS’s allow you to set continuous and peak currents with peak current duration times as well - See how you go.
Balanced open start voltage = 3.45v - although this is meaningless as the balance current the Daly provides is useless for a 230Ah battery. It’s less than 30mA from memory.
Balance open diff voltage - 0.02v - see above limitation for start voltage.
SOC set, get the battery fully charged then set it to 100%. This tells the BMS a reference starting SOC.
Sum high/low voltages refer to the battery voltages but we really want to protect at a cell level, not a battery level so ensure they are set sufficiently high/low that they don’t impede performance.
Set your charger voltage to 56.8v (3.55v per cell)

This should get you started safely.

Cheers
Pat.

[Croqezgo]

Pat, you are awesome!

[Croqezgo]

what do you recommend for the SUM values?

[Pat911]

Just set high to 16x3.65 = 58.4v and low to 16x2.5 = 40v although as I already mentioned these limits should never be met as the high/low cell voltage protection should kick in before the pack high/low voltages are ever met.

[Croqezgo]

That is awesome! My charger is a Lester summit II and it has a lifepo4 charger profile. The parameters are:

13.5A Bulk Charge to 56V 3.5VPC.

Is that safe to use on these batteries? When I looked, 3.5V is really a 95% SOC or so. I think Lifepo4 batteries are happy between 90% and 20% SOC never below 20%. Is that correct? I really want to use this charger if possible.