Table 2 Test procedure 2 of charge and discharge profile measurement.
From: Charge and discharge profiles of repurposed LiFePO4 batteries based on the UL 1974 standard
Procedure and Step | Action | Key Parameters | Description | As per UL 1974 |
|---|---|---|---|---|
P2S1 | Rest | \({t}_{rest}=1\) minute | Rest for 1 minute, and observing the stability of OCV | N/A |
P2S2 | Charge in CC-CV mode | CC: \({I}_{const}=0.5Ca{p}_{RX}/{\rm{h}}\) CV: \({V}_{thres}=3.5\) V, \({I}_{cut}=0.05Ca{p}_{RX}/{\rm{h}}\) | Full charge at \({C}_{R}=0.5{{\rm{h}}}^{-1}\) | 19.5 |
P2S3 | Rest | \({t}_{rest}=1\) hour | Rest for 1 hour | 19.5 |
P2S4 | Discharge in CC mode | CC: \({I}_{const}=0.2Ca{p}_{RX}/{\rm{h}}\), \({t}_{s}\ge {t}_{1}\) | Two-tier DC load method at \({\rm{SOC}}=85 \% \) and obtaining \({V}_{85,1}\) and \({I}_{85,1}\) | 19.5 |
P2S5 | Discharge in CC mode | CC: \({I}_{const}=1Ca{p}_{RX}/{\rm{h}}\), \({t}_{s}={t}_{2}\) | Two-tier DC load method at \({\rm{SOC}}=85 \% \) and obtaining \({V}_{85,2}\) and \({I}_{85,2}\) | 19.5 |
P2S6 | Discharge in CC mode | CC: \({I}_{const}=0.5Ca{p}_{RX}/{\rm{h}}\) | Discharge to \({\rm{SOC}}=20 \% \) | 19.5 |
P2S7 | Rest | \({t}_{rest}=1\) hour | Rest for 1 hour | 19.5 |
P2S8 | Discharge in CC mode | CC: \({I}_{const}=0.2Ca{p}_{RX}/{\rm{h}}\), \({t}_{s}={t}_{1}\) | Two-tier DC load method at \({\rm{SOC}}=20 \% \) and obtaining \({V}_{20,1}\) and \({I}_{20,1}\) | 19.5 |
P2S9 | Discharge in CC mode | CC: \({I}_{const}=1Ca{p}_{RX}/{\rm{h}}\), \({t}_{s}={t}_{2}\) | Two-tier DC load method at \({\rm{SOC}}=20 \% \) and obtaining \({V}_{20,2}\) and \({I}_{20,2}\) | 19.5 |
P2S10 | Discharge in CC mode | CC: \({I}_{const}=0.5Ca{p}_{RX}/{\rm{h}}\), \({V}_{cut}=2.5\) V | Full discharge at \({C}_{R}=0.5{{\rm{h}}}^{-1}\) | N/A |
P2S11 | Rest | \({t}_{rest}=1\) hour | Rest for 1 hour | N/A |
P2S12 | Charge in CC-CV mode | CC: \({I}_{const}=0.5Ca{p}_{RX}/{\rm{h}}\) CV: \({V}_{thres}=3.5\) V, \({I}_{cut}=0.05Ca{p}_{RX}/{\rm{h}}\) | Full charge at \({C}_{R}=0.5{{\rm{h}}}^{-1}\) and obtaining \(Ca{p}_{C1}\) | 19.7 |
P2S13 | Rest | \({t}_{rest}=1\) hour | Rest for 1 hour | 19.7 |
P2S14 | Discharge in CC mode | \({I}_{const}=0.5Ca{p}_{RX}/{\rm{h}}\), \({V}_{cut}=2.5\) V | Full discharge at \({C}_{R}=0.5{{\rm{h}}}^{-1}\) and obtaining \(Ca{p}_{DN}\) | 19.7 |
P2S15 | Rest | \({t}_{rest}=1\) hour | Rest for 1 hour | 19.7 |
P2S16 | Charge in CC-CV mode | CC: \({I}_{const}=0.5Ca{p}_{RX}/{\rm{h}}\) CV: \({V}_{thres}=3.5\) V, \({I}_{cut}=0.05Ca{p}_{RX}/{\rm{h}}\) | Full charge at \({C}_{R}=0.5{{\rm{h}}}^{-1}\) and obtaining \(Ca{p}_{C2}\) | 19.7 |
P2S17 | Rest | \({t}_{rest}=1\) hour | Rest for 1 hour. | 19.7 |
P2S18 | Discharge in CC mode | \({I}_{const}=1Ca{p}_{RX}/{\rm{h}}\), \({V}_{cut}=2.5\) V | Full discharge at \({C}_{R}=1{{\rm{h}}}^{-1}\) and obtaining \(Ca{p}_{DM}\) | 19.7 |
P2S19 | Rest | \({t}_{rest}=1\) hour | Rest for 1 hour | N/A |
P2S20 | Charge in CC-CV mode | CC: \({I}_{const}=0.5Ca{p}_{RX}/{\rm{h}}\) CV: \({V}_{thres}=3.5\) V, \({I}_{cut}=0.05Ca{p}_{RX}/{\rm{h}}\) | Full charge at \({C}_{R}=0.5{{\rm{h}}}^{-1}\) and obtaining \(Ca{p}_{C3}\) | 19.8 |
P2S21 | Rest | \({t}_{rest}=5\) minutes | Rest for 5 minutes after P2S20 and obtaining \(OC{V}_{5{\rm{m}}}\) | 19.8 |
P2S22 | Rest | \({t}_{rest}=55\) minutes | Rest for 1 hour after P2S20 and obtaining \(OC{V}_{1{\rm{h}}}\) | 19.8 |
P2S23 | Rest | \({t}_{rest}=23\) hours | Rest for 24 hours after P2S20 and obtaining \(OC{V}_{24{\rm{h}}}\) | 19.8 |
