## 1 Introduction
Thus, if the battery chemistry is untampered and a new design is developed, it can achieve more in terms of satisfying vehicle load requirements. Again, the new design has to depend on the cell-to-pack design and battery size for better performance [18]. On the other hand, lithium-ion batteries (LIBs) have a wide attraction in modern automobile technologies such as EVs and PHEVs because of their superior performance, decreasing cost, and recently, as a \"drop-in\" to replace LABs in ICEVs. Nevertheless, LIB's market share remains low in these applications [19]. The current price of these batteries is still high, and it requires a significant reduction for wide adoption [20]. Moreover, these batteries may pose thermal runway and safety concerns if used as an SLI because of the abused operating nature of this application [5]. In addition, LIBs face extreme difficulty in using their energy, especially at a pack level, because active or passive cell balancing becomes crucial. Despite these challenges, the LIBs have a high energy density, high utilisation efficiency, long lifespan, and are friendly to the environment. The developed lithium-ion phosphate batteries (LFPs) have many advantages compared to the conventional LIBs because their material is abundant, safe, weigh less, has high cycling loads, reduced memory effect, has higher power density, and is less costly. They are commercially available and used in many applications such as storage for renewable energy, electric buses, and EVs (e.g. Tesla, Volkswagen, Renault, and Ford) because of their good thermal/cycling stability, safety, and resilience to the environment [7; 12; 18; 21; 22]. Even though they have the best combination of excellent properties for certain vehicle applications, the use of Li-ion batteries in developing and underdeveloped economies for SLI functions remains a challenge because of the lack of established recycling processes and factories. The adoption of various combinations of battery storage systems may increase the chance to clean and less-carbon TVs [23], and without tampering with battery chemistry, the new battery designs may be developed, thus depending on the battery size [18]. Hence, providing cost tradeoff [24] of hybrid different battery technologies requires an excellent power management system to adequately share the power and improve the performance of these batteries in terms of lifespan, power delivery, and storage capacity. Moreover, because generally, during vehicle operation, the unstable power supply may occur and cause unusual operation of these devices, the power management and control could stabilise the power distribution of the energy storage systems, thus managing load demand effectively [25], enhancing battery safety, reliability, and security, respectively. Still, BMSs face different challenges, such as diversity of applications and withstanding unprecedented hazardous events [26]. Therefore, the main purpose of this research paper is to improve LABs' performance in terms of lifespan and storage capacity. Because this study accomplishes its objective without tampering with LAB chemical composition, hence; there is a need for a complex system comprising power electronics for managing power in/out of the combined ESSs rather than a simple system of replacing LAB with Li-ion battery. The proposed solution provides a sound practical value because LABs are easily accessible and less costly in developing and underdeveloped economies. Additionally, this study gives significant theoretical value. Furthermore, a Li-ion battery as a replacement for LAB is not a good solution because currently, it has a higher cost, is not competitive with LABs, has low recycling efficiency, and in terms of safety, high power demand in ICEVs may vary, and it is unknown at this stage as to how they will perform under such circumstances. In the proposed solution, there is no feasible reliability because the system operates effectively over its lifespan during the investigation.