A battery is a portable energy source that converts chemical energy to electrical energy. Simply put, batteries contain three basic parts: the electrodes, the electrolyte and a separator. There are always two electrodes in a battery: the cathode is connected to the positive end, while the anode is connected to the negative end. When the battery powers a load, it discharges, and current flows from the cathode to the anode. When the battery charges, current flows from the anode to the cathode.
Electrodes are immersed in an electrolyte, a liquid or gel substance that contains the electrically charged ions that react with the electrodes. This chemical process causes the battery to generate electricity. The separator physically separates the electrodes. Without it, the electrodes would come into contact and be short-circuited, destroying the battery. Batteries provide electricity in the form of direct current (DC), but an inverter can be used to achieve alternating current(AC). The most important parameters of any battery are the following:Nominal cell voltage
- Nominal cell voltage
- Nominal capacity
- Battery type
- Number of cells in the battery string
There are three main types of rechargeable batteries: lead-acid, nickel-cadmium (NiCd) and lithium-ion.
What’s a Good Battery for Solar Energy Systems?
Deep-cycle storage capability is a mandatory feature for batteries in a solar energy system. Lead-acid batteries have this feature, as they can be discharged up to 80 percent of total capacity without any repercussions. Flooded lead-acid batteries are the most commonly used batteries in solar energy systems, as they also have a long lifespan and are cost-effective.