How is the solar energy storage battery calibrated? In solar lamps, we generally use ternary lithium batteries or lithium iron phosphate batteries. The average output voltage of the ternary lithium battery is 3.7 volts, and the average output voltage of the lithium iron phosphate battery is 3.2 volts. In general, the energy density of ternary lithium batteries is greater, but the price will be higher. In the case that we have to limit the weight of the lamp or the size of the lamp, we will use ternary lithium batteries, in other cases, we generally use lithium iron phosphate batteries. So how do we understand the nominal capacity of a battery? Suppose you have a lithium iron sulfate battery with a nominal 30 AH (Amp X Hour). Calculated at 3.2 volts of operating Voltage, Ideally, the amount of energy of the battery is 96WH(Watt X Hour). In fact, as the working Voltage of the LED chip is about 3.0V, and for the protection of the battery, we generally leave 5% of the energy never to be running up. So the amount of energy that this battery can be used is about 85 WH. For example, SEKURO Solar Street light SKEP303-300, the Max working wattage is 30W, so it will run out of 85WH in its 30AH battery within three hours. So how to make sure that SKEP303-300 can keep working continually for 14hours? Thanks to the intelligent solar light controller, it will detect the percentage of the energy stored in the battery when it start to work. In the sunny day, usually the battery will be charged to full during the daytime, work with the automatic program, the controller direct the output of the battery in smart way. In the first hour, the output will be 100%-75%, then second hour, 75%-50%, then in the third hour, dropping from 50% to 15% and keep working at about 15% all over the night. Once in the rainy day, the controller limit the output even start from 15% to make sure the light is able to work all over the night.