Almost all portable electronic devices such as cell phones, laptops, and remote-control toys use batteries as their power source. In certain cases, it was found that the battery could be damaged and short-lived. Damage to the battery is caused by using the battery that is less than the maximum. One example that can be taken in this regard is the battery connected to the PLTS system. Battery storage in PLTS can still be developed further so that the battery can work optimally and extend battery life. The case starts with conditioning the battery room temperature and the Depth of Discharge value which will shorten battery life. So to estimate this value we need a method, one of the methods that can be used is the Coulomb Counting method. This method is used to measure the value of the electric charge entering or leaving the battery. From the results obtained, the Coulomb Counting method can calculate the usage time of a 12V 200Ah VRLA battery with an average Depth of Discharge of Battery 1 DoD 39.02% DoD Battery 2 40.25% DoD Battery 3 41.92% DoD Battery 4 40.98% for 30 days. Conditioning is also carried out by maintaining the value of the depth of discharge of the battery so that it can maintain the value of Depth of Dis-charge with an average of each battery respectively 40.00%, 40.73%, 42.88% and 41.09%. From this conditioning, the estimated battery lifetime values were 3.77 years, 3.68 years, 3.45 years, and 3.64 years respectively.