Defective Daly BMS or user error?

[MullerEnergy-Australia]

I've sold a client 16x 272Ah Lishen batteries and when he asked me what BMS to get, I recommended that he get a 150A Daly Smart BMS.
So now he installed the Lishens, they have a voltage of around 53V, which is pretty good, however we can't get the BMS to work when the inverter is on.

To turn on the BMS, we (I say we, but he's doing everything, I'm just on facetime with him) connected B- and P-. If this is done with the inverter disconnected, the BMS turns on, however it's only showing 48V potential between P+ and P-, so 4-5V lower than between P+ and B-. I'm not sure that's right.

But once the inverter is connected, the BMS trips and P+ to P- drops to around 8V. If B- and P- is then connected, there's a big spark. The inverter a Giant Power 4000WM (the same as an MPP PIP-4048MS and a long list of other rebadged inverters).

Unfortunately the client does not have a resistor to pre-charge the inverter capacitors, as I think this could potentially be the problem.

As it's an off-grid property, he's reliant on the batteries working, so he's currently running it without the BMS, which is working fine (I told him to keep an extremely close eye on the cell voltages).

While I know I'm not really responsible, as I only supplied the cells and not the inverter or the BMS, I did recommend the BMS to him and definitely want to help him fix it. However, I think I'm somewhat out of ideas.

So if any of you know whether it's a simple user error, the inverter caps or perhaps a defective BMS, any help would be very much appreciated!

I got him to check the balance leads twice, just to make sure that wasn't the problem.

Thanks!

List of inverters that are the same as his below:
Axpert MKS 5K
Mecer (rhymes with "spacer") MKS 5K (from Mustek)
Mecer SOL-I-AX-5M, SOL-I-AX-5P and SOL-I-AX-5P64
IPS-4000WM (from Giant Power)
Effekta AX-M 5 kVA
Flinslim MPPT 5kVA
OPTI-Solar SP5000 Brilliant
MAXIC5000-48
Pro Power 48V 4000W Integrated Power System
SP5000-48MPPT80
Proline Energy inverter 5kVA 48V w/MPPT SCC
Inverex MKS 5KVA
SOLARIX PLI 5000-48 (from Steca Electronik GMBH)
Voltex MKS 5KVA
RCT Axpert 5000VA
SolarPower24 Primo MKS 5K-48, Primo MKS(PF1) 5K-48, Primo MKS(PF1) 5K-48H

 

[trevor.the.van]

Double check the balance cables are all connected correctly, perhaps a bad connection and once the current draw happens it thinks a cell has died?

 

[Zwy]

I've sold a client 16x 272Ah Lishen batteries and when he asked me what BMS to get, I recommended that he get a 150A Daly Smart BMS.
So now he installed the Lishens, they have a voltage of around 53V, which is pretty good, however we can't get the BMS to work when the inverter is on.

To turn on the BMS, we (I say we, but he's doing everything, I'm just on facetime with him) connected B- and P-. If this is done with the inverter disconnected, the BMS turns on, however it's only showing 48V potential between P+ and P-, so 4-5V lower than between P+ and B-. I'm not sure that's right.

But once the inverter is connected, the BMS trips and P+ to P- drops to around 8V. If B- and P- is then connected, there's a big spark. The inverter a Giant Power 4000WM (the same as an MPP PIP-4048MS and a long list of other rebadged inverters).

Unfortunately the client does not have a resistor to pre-charge the inverter capacitors, as I think this could potentially be the problem.

As it's an off-grid property, he's reliant on the batteries working, so he's currently running it without the BMS, which is working fine (I told him to keep an extremely close eye on the cell voltages).

While I know I'm not really responsible, as I only supplied the cells and not the inverter or the BMS, I did recommend the BMS to him and definitely want to help him fix it. However, I think I'm somewhat out of ideas.

So if any of you know whether it's a simple user error, the inverter caps or perhaps a defective BMS, any help would be very much appreciated!

I got him to check the balance leads twice, just to make sure that wasn't the problem.

Thanks!

List of inverters that are the same as his below:
Axpert MKS 5K
Mecer (rhymes with "spacer") MKS 5K (from Mustek)
Mecer SOL-I-AX-5M, SOL-I-AX-5P and SOL-I-AX-5P64
IPS-4000WM (from Giant Power)
Effekta AX-M 5 kVA
Flinslim MPPT 5kVA
OPTI-Solar SP5000 Brilliant
MAXIC5000-48
Pro Power 48V 4000W Integrated Power System
SP5000-48MPPT80
Proline Energy inverter 5kVA 48V w/MPPT SCC
Inverex MKS 5KVA
SOLARIX PLI 5000-48 (from Steca Electronik GMBH)
Voltex MKS 5KVA
RCT Axpert 5000VA
SolarPower24 Primo MKS 5K-48, Primo MKS(PF1) 5K-48, Primo MKS(PF1) 5K-48H

Daly 24V 8S Initiation and Software

I'm going to consolidate some of the Daly Smart BMS questions into one thread concerning initialization and parameter setting, some of it I found here in odds and ends, some I discovered on my own. First off, thanks to those who pioneered ahead of me and found ways to get these to work. I...

diysolarforum.com

 

[squowse]

Does the BMS work OK with any other 48V loads? Certainly sounds like the initial draw of the inverter is being mistaken for a short by the BMS. It's a real problem, I wonder if some manufacturers build in a "soft start" to their inverters?

 

[squowse]

I believe a filament bulb can be used instead of a resistor if that's easier to get hold of

 

[Supervstech]

Like he said above, an incandescent light bulb works great as a charge resistor.
Any resistive device will work.
Got a toaster?

 

[Bob B]

Or .... since he has the inverter running by connecting direct to the battery ..... remove load from the inverter and connect a temporary jumper from battery to inverter .... this is to keep the capacitors charged .... then reset the BMS and connect normally thru the BMS .... removed the jumper.

 

[Siji]

Had a similar problem using phocos anygrid inverter and Daly 150amp BMS. The problem was just my failure to tighten just one connection on the battery.. any time I turned on inverter and added load BMS would immediately trip.