## 5 Conclusions  
The authors understand too little about batteries. S.-S.Y. has been developing Battery Management System (BMS) hardware since 2009, but, as the use cases of batteries have expanded, more questions have arisen; therefore, this study was conducted by organizing the knowledge so far. Batteries can more efficiently use depleted energy, and, even if alternative energy is discovered, efficient operation requires the necessary technology. The authors believe that deeper research into these fundamental technologies will open up a beautiful future for our descendants. The authors conclude that a battery with a relatively small capacity due to gradual damage gradually increases in voltage, and the activity of chemical reactions increases due to a rise in the thermal energy caused by a temperature change, resulting in a rise in the highest voltage, exceeding the protection voltage of the BMS, and causing a battery fire. At this time, the voltage change for the thermal energy of the battery is affected by the SOC-OCV curve, so it is assumed that a larger voltage change occurs for the same energy in the range where the voltage or the SOC is high. In the future, the authors plan to conduct battery fire demonstration experiments according to temperature changes under overvoltage conditions and study the possible solutions.  
Conceptualization, S.-S.Y.; methodology, S.-S.Y.; software, S.-S.Y.; validation, S.-S.Y. and S.-C.K.; formal analysis, S.-S.Y.; investigation, S.-S.Y.; resources, S.-S.Y. and S.-C.K.; data curation, S.-S.Y.; writing--original draft preparation, S.-S.Y. and S.-C.K.; writing--review and editing, S.-S.Y. and S.-C.K.; visualization, S.-S.Y.; supervision, S.-C.K.; project administration, S.-S.Y. and S.-C.K.; funding acquisition S.-C.K. All authors have read and agreed to the published version of the manuscript.  
This research was supported by the Ministry of Science and ICT (MSIT), South Korea, under the Grand Information Technology Research Center support program (IITP-2023-2020-0-01462), supervised by the IITP (Institute for Information & communication Technology Planning & evaluation). This work was supported by a National Research Foundation of Korea (NRF) grant funded by the South Korean government (MSIT) (No. 2022R1A5A8026986).  
Not applicable.  
\begin{table}
\begin{tabular}{c c c} \hline \hline \multicolumn{1}{c}{**Condition**} & \multicolumn{1}{c}{**Max. Volt.**} & \multicolumn{1}{c}{**Max. Aging Progress**} \\ \hline Volt. ref. cell balance with capacity deviation \(\pm\)1\% & 4.213 V (Bat \#3) & 64.15\% (Bat \#3) \\ Volt. ref. cell balance with capacity deviation \(\pm\)2\% & 4.275 V (Bat \#3) & 65.25\% (Bat \#3) \\ Volt. ref. cell balance with capacity deviation \(\pm\)3\% & 4.331 V (Bat \#3) & 66.62\% (Bat \#3) \\ Proposed cell balance with capacity deviation \(\pm\)1\% & 4.167 V (Bat \#3) & 63.63\% (Bat \#3) \\ Proposed cell balance with capacity deviation \(\pm\)2\% & 4.177 V (Bat \#1, \#4) & 63.93\% (Bat \#3) \\ Proposed cell balance with capacity deviation \(\pm\)3\% & 4.211 V (Bat \#2) & 60.62\% (Bat \#3) \\ \hline \hline \end{tabular}
\end{table}
Table 11: Comparison of simulation results of the cell balance method of the existing simple voltage comparison method and the proposed cell balance method.