DALY BMS Help

[Johnny_C]

I have a 24V 500AH battery pack constructed of 8 LIFEPO4 cells connected in series with copper buss bars. I am also using a 300AMP DALY BMS with the pack. My inverter is a Victron Quattro 24/5000/120. My issue is when I run a high AC load, really anything over 500watts, the Inverter shuts off with a "Low Voltage" error code. I worked with Victron to make sure all my inverter settings are correct so the only thing left is the battery pack and BMS. Using a heat gun to test, when I turn it, on my 12V LED light strip in the electronics compartment dims but one the Inverter shuts off the light comes back on to full brightness. I am also using a Victron Orion DC-DC converter for my 12V distribution. The Victron Smart Shunt is reading the battery pack at 28.5V's when I start the test. Using a volt meter, the Inverters input does drop to ~ 24V's when the heat gun is turned on. Low voltage cutoff on the Inverter is set for 18.6V per Victron's recommendation. Is my issue with the BMS or the battery pack? What is the best way to test without buying another BMS?

 

[Higher_wire]

Connect the load directly to the B- wire in the Daly and test. Also check that your balance leads are wired correctly, and that bus bars are tight Against battery electrodes.

 

[Johnny_C]

Verified all connections were tight so I bypassed the DALY BMS with a cable and the battery pack supported an AC Load of 1500 Watts without issue. I had an old 200Amp DALY that is connected to the battery pack and it too supported the 1500 Watt AC load. The end result is a BAD DALY 250Amp with FAN BMS. The down side of the 200Amp DALY that is working is there is no Bluetooth monitoring available. I guess I just have to hope it is doing its job.

 

[Johnny_C]

Not very happy with DALY, any recommendations on a replacement? I went with a 250Amp because my Victron Quattro can support 5000Watts. I really doubt if I use 5000 Watts but the potential is there. Adding 10% for inverter inefficiencies and would be ~ 230Amps (5000W/24V+10%=229A).

 

[MisterSandals]

Not very happy with DALY,

That’s how quite a few folks feel too.

I think the JBD, Overkill and JK BMS users are equally content with how they work. A definite step up to solid performers IMHO.

 

[webyoo]

Verified all connections were tight so I bypassed the DALY BMS with a cable and the battery pack supported an AC Load of 1500 Watts without issue. I had an old 200Amp DALY that is connected to the battery pack and it too supported the 1500 Watt AC load. The end result is a BAD DALY 250Amp with FAN BMS. The down side of the 200Amp DALY that is working is there is no Bluetooth monitoring available. I guess I just have to hope it is doing its job.

Thanks for that suggestion Higher_wire I have just bypassed my Daly 8s 250w confirming the system works fine without the Daly BMS.