The purpose of this research is to look at how two important lead-acid batteries, the 12V/100Ah Sun Test Gel and the 12V/100Ah AGM sealed lead-acid batteries, perform during discharge in photovoltaic (PV)-based systems in Nigeria. In harsh climatic conditions, such as in Nigeria, where temperatures can reach extremely high levels during the dry season when there is plenty of sunlight, battery performance improves. In this work, the discharge properties of two comparable batteries are compared through discharge testing on two distinct batteries. The results of the discharge tests, as well as a comparison of the two batteries, are presented in this paper.