# Evaluating Effects of Electric Vehicle Chargers on Residential Power Infrastructure
## 1 Introduction
Such distances can be readily accommodated by low-power residential chargers, making home-based charging a practical and efficient solution for most users [11]. However, the installation of high-capacity chargers in individual homes may present significant challenges, primarily due to the limited capacity of existing residential electrical systems [12]. Current electric vehicles can store approximately 18 to 100 kWh of energy, depending on the model and battery configuration. While this energy range is generally sufficient for daily commuting needs, it can impose a substantial electrical load when high-power charging is utilized, particularly in older buildings not originally designed to accommodate such demands. As a result, many residential installations require infrastructure upgrades, which can be both costly and technically complex [13; 14; 15]. The scenario in multi-residential buildings, particularly condomiums, presents unique technical and economic challenges, as well as emerging opportunities. The installation of EV chargers in such settings has been steadily increasing, driven by the rising number of EV owners and the potential value that it adds for property developers and investors [16]. However, retrofitting charging infrastructure in existing apartment complexes is often constrained by financial and structural limitations. Studies have found that the cost of installation, coupled with limited electrical capacities and shared ownership structures, can hinder the widespread deployment of EV chargers in these buildings [17]. From an investor's perspective, installing EV chargers in condominiums is beneficial due to the high concentration of potential users in a single location [18]. Condominiums, which house numerous occupants per building, present a significant opportunity for operational efficiency and return on investment. The convenience of charging facilities can also be a selling point for prospective buyers or tenants, adding value to the property [19]. However, condominiums present significant challenges for the integration of EV chargers due to their shared electrical infrastructure, which requires coordinated management to ensure a balanced load distribution across residential units [20]. Older buildings constructed prior to the rise of electric mobility typically lack the electrical capacity and structural provisions necessary to support EV charging, making retrofitting efforts both technically and financially demanding [21; 22; 23]. Upgrading the electrical infrastructure in these buildings often involves high costs, spatial constraints, and regulatory complexities. Moreover, most existing systems were not designed to accommodate the high and variable loads associated with simultaneous EV charging. This can lead to critical operational issues, such as transformer overloads, voltage drops, increased system wear, and even localized power outages. Although several studies have discussed these constraints conceptually or through simulation, there remains a lack of field-based evidence capturing how such issues manifest under real charging conditions in shared residential environments. In particular, few studies have investigated these challenges through integrated power quality measurements within actual condominium settings, especially in Southeast Asian urban contexts. This gap highlights the need for empirical studies that reflect both the technical and behavioral complexities of EV charger adoption in existing multi-unit buildings. Building on these infrastructure-related concerns, a deeper understanding of how EV charging behavior interacts with residential electrical systems has become increasingly important [24; 25]. Without adequate planning, the integration of EV chargers could compromise the safety, reliability, and operational efficiency of building-wide electrical systems [26; 27].