Characteristics of Lead-Acid Battery Charging and Discharging Against Residential Load in Tropical Area

Electrical system in remote areas that cannot be connected to national electricity networks can be served by installing solar based off grid system. The battery bank energy storage as an important part of off grid PV system still have challenges in renewable energy systems and hardly depend on weather conditions. This article will focus on the characteristics of lead-acid battery charging and discharging against residential loads. The research methodology used by testing the rooftop PV system for residential load useage which consists of 2 units 200 Ah battery, 1 unit off-grid inverter 1500 VA, 4 solar panels 260 Wp/unit, and vary residential AC load. The PV loading test was conducted to achieve battery average internal resistance as well as state of charge (SOC). The results of battery characteristics testing show that when clear sky during the day, the charging current is sufficient to charge batteries, so even high load such as air conditioner operated, PV generation still capable in serving loads without termination. The system will be interrupted only if the inverter current limit exceed. This battery usage characteristics can be used as a basis for further demand side management of residential load powered by PV system to improve continuity supply.