In most UPSs, you don’t use just one cell at a time. They’re normally grouped together serially to form higher voltages, or in parallel to form higher currents. In a serial arrangement, the voltages add up. In a parallel arrangement, the currents add up.
However, batteries are not quite as linear as the two graphics to the right depict. For example, all batteries have a maximum current they can produce; a 500 milliamp-hour battery can’t produce 30,000 milliamps for one second, because there’s no way for its chemical reactions to happen that quickly. It is also important to realize that at higher current levels, batteries can produce a lot of heat, which wastes some of their power.
Like all batteries, UPS batteries are electrochemical devices. A UPS uses a lead-acid storage battery in which the electrodes are grids of lead containing lead oxides that change in composition during charging and discharging, and the electrolyte is dilute sulfuric acid. In other words, they contain components that react with each other to create DC electrical current. These components are:
Electrolyte: The medium that provides the ion transport mechanism between the positive and negative electrodes of a cell, immobilized in VRLA batteries, and in liquid form in flooded-cell batteries
Grid: A perforated or corrugated lead or lead alloy plate used as a conductor and support for the active material
Anode: The terminal where the current flows in
Cathode: The terminal where the current flows out
Valve: (used in VRLA batteries) Used to vent the build-up of gas that goes beyond pre-determined levels
Separator: A device used for the physical separation and electrical isolation of electrodes of opposing polarities
Jar: The container holding the battery components
In Series Connection: Connecting of the positive terminal of a cell/battery to the negative terminal of the next cell/battery increases the voltage of the battery network while keeping the capacity constant. Voltage becomes double, Capacity remains same (ah).
