There are two factors that affects battery capacity, ambient temperature and discharge rate. Ambient temperature can affect battery parameters such as voltage, capacity and battery life. Battery discharge current is influenced by the load associated with the battery. The load used needs to be adjusted to the battery capacity that will be used so that the discharge current produced by the battery is in accordance with its rating of use as the discharge flow generated by the battery can affect the battery's capacity. Therefore, research on the effect of environmental temperature and current discharge on lead-acid batteries with a deep-discharge method is required to see the battery capacity at different ambient and discharge temperatures. From the research that have been carried out, the capacity ratio is directly proportional to the ambient temperature and inversely proportional to the battery discharge current. For example, on 30°C test, battery capacity at 2 Ohms, 3 Ohms and 4 Ohms respectively are 57.783, 58.74 and 60.467 Wh. Another example is on 2 Ohm load, battery capacity at 30°C, 40°C and 50°C are 57.783, 58.175 and 58.213 Wh respectively.