MrM1
I'm Here, But I'm Not All There
I am trying to learn my actual State of Charge of my battery bank.
I'm not totally new at all this, but still learning. I'm not sure what I am seeing in my Shunt Percentage vs Cell Voltage of my battery bank.
I have a 24v system with a Schneider SW 4024 Inverter, two Classic 150s SCCs, and a 5200 watt array
Using Busbars for combining from positive and negative and equal cable lengths from each of the 3 batteries I have
- A 2p8s battery of 304ah eve cells / Overkill Solar BMS with an entered Amp Hour of 608
- A 2p8s battery of 230ah eve cells / Overkill Solar BMS with an entered Amp Hour of 460
- A 8s battery of 271ah CATL cells / Overkill Solar BMS with an entered Amp Hour of 271
The Midnite Classic 150 SCC (with Shunt and Whizbang Jr for reading Amp Hours) is entered in as 1,339 Total Amp Hours for the Battery Bank.
Here's the Question:
- The MidNite Solar Shunt And all the BMS's pretty much agree. This morning the system is at 17% SOC.
- The Capacity / Net Charge according to the Midnite Solar shunt is -1011 Ah (which lines up with the total Amp Hours of 1,339Ah if at 17%)
- The SCC is reporting the Total Battery Bank voltage as 25.7v with a total load of 594 watts
- The Array is turned off
BUT ... even with a Load of 594 watts on these batteries,
- My Individual Cell voltage of each of the 40 cells is on average at 3.24v per cell even with a steady 594 watt load
- The Delta between all cells is no more than 0.005v
So ... Wouldn't the Cell Voltage indicate that the SOC is actually higher than what the Shunt is Reporting at 17%?
- Wouldn't the SOC Actually be closer to 35% according to cell voltage?
Is something Calibrated Wrong ?
Do I go with the Shunt or the Cell Voltage Chart?
I guess i could just run the whole thing down until the BMSs started turning off the batteries (LVC set to 2.7 in the BMS). Then I'd see how low the Shunt read. That'd be fun ?
I'm not totally new at all this, but still learning. I'm not sure what I am seeing in my Shunt Percentage vs Cell Voltage of my battery bank.
I have a 24v system with a Schneider SW 4024 Inverter, two Classic 150s SCCs, and a 5200 watt array
Using Busbars for combining from positive and negative and equal cable lengths from each of the 3 batteries I have
- A 2p8s battery of 304ah eve cells / Overkill Solar BMS with an entered Amp Hour of 608
- A 2p8s battery of 230ah eve cells / Overkill Solar BMS with an entered Amp Hour of 460
- A 8s battery of 271ah CATL cells / Overkill Solar BMS with an entered Amp Hour of 271
The Midnite Classic 150 SCC (with Shunt and Whizbang Jr for reading Amp Hours) is entered in as 1,339 Total Amp Hours for the Battery Bank.
Here's the Question:
- The MidNite Solar Shunt And all the BMS's pretty much agree. This morning the system is at 17% SOC.
- The Capacity / Net Charge according to the Midnite Solar shunt is -1011 Ah (which lines up with the total Amp Hours of 1,339Ah if at 17%)
- The SCC is reporting the Total Battery Bank voltage as 25.7v with a total load of 594 watts
- The Array is turned off
BUT ... even with a Load of 594 watts on these batteries,
- My Individual Cell voltage of each of the 40 cells is on average at 3.24v per cell even with a steady 594 watt load
- The Delta between all cells is no more than 0.005v
So ... Wouldn't the Cell Voltage indicate that the SOC is actually higher than what the Shunt is Reporting at 17%?
- Wouldn't the SOC Actually be closer to 35% according to cell voltage?
Is something Calibrated Wrong ?
Do I go with the Shunt or the Cell Voltage Chart?
I guess i could just run the whole thing down until the BMSs started turning off the batteries (LVC set to 2.7 in the BMS). Then I'd see how low the Shunt read. That'd be fun ?
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