svHope
New Member
- Joined
- Nov 28, 2019
- Messages
- 23
Hello
I am still learning about the 4S REC BMS. My question this time is related to the SOC. I question the accuracy of the process used to determine the SOC. For instance, I charge my small 20 AH 4S pack to about 3.65volts per cell (I must say I am very impressed as to how well the BMS balances the pack). The Charge End parameter is set to 3.68. The SOC meter tops out at 100%. I then load the pack with various loads from 1-9 amps. the SOC drops over time vs the load. At some point the SOC shows 20% or less yet my cell voltages are about 3.18-3.2 volts. I know that there is more capacity left in the pack as I continue to load the pack until the voltage is about 2.9 volts per cell. At that time the SOC shows 1-3% left. As a cross check I am also using a Victron BMV 712 (parameters are set on the 712 for typical LiFePo4) to monitor SOC. When the SOC on the REC shows 20%, the Victron shows around 40% SOC. Can anyone give me some ideas on how to understand this situation?
I am still learning about the 4S REC BMS. My question this time is related to the SOC. I question the accuracy of the process used to determine the SOC. For instance, I charge my small 20 AH 4S pack to about 3.65volts per cell (I must say I am very impressed as to how well the BMS balances the pack). The Charge End parameter is set to 3.68. The SOC meter tops out at 100%. I then load the pack with various loads from 1-9 amps. the SOC drops over time vs the load. At some point the SOC shows 20% or less yet my cell voltages are about 3.18-3.2 volts. I know that there is more capacity left in the pack as I continue to load the pack until the voltage is about 2.9 volts per cell. At that time the SOC shows 1-3% left. As a cross check I am also using a Victron BMV 712 (parameters are set on the 712 for typical LiFePo4) to monitor SOC. When the SOC on the REC shows 20%, the Victron shows around 40% SOC. Can anyone give me some ideas on how to understand this situation?
