Energy storage batteries mainly refer to batteries used in solar power generation equipment, wind power generation equipment, and renewable energy storage. Energy storage batteries primarily store electrical energy. When supplying power, energy storage batteries do not experience the same fluctuations as power batteries; their output is relatively stable, typically characterized by low discharge current and long discharge time. Another requirement for energy storage batteries is a long lifespan, generally around 5 years.
Classification of energy storage batteries
The most common type of energy storage battery is the lead-acid battery (lithium-ion energy storage batteries using lithium iron phosphate as the positive electrode material are being gradually developed). Energy storage batteries are divided into the following three categories:
1. Exhaust-type lead-acid battery for energy storage: A battery with a cover that can replenish liquid and release gas.
2. Valve-regulated lead-acid batteries for energy storage: Each battery is sealed, but each has a valve that allows gas to escape when the internal pressure exceeds a certain value.
3. Gel-electrode lead-acid batteries: Batteries that use gel electrolytes.
Features of energy storage batteries
Lead-acid batteries for energy storage must have the following characteristics:
1. It has a wide operating temperature range, and is generally required to operate normally in a temperature environment of -30 to 60 degrees Celsius.
2. The battery should have good low-temperature performance so that it can be used even in areas with relatively low temperatures.
3. Good capacity consistency, maintaining consistency in both series and parallel battery connections.
4. It has good charging acceptance, and is more receptive to charging in unstable charging environments.
5. Long lifespan reduces maintenance and repair costs, lowering overall system investment.
The charging status of wind and solar energy storage batteries, derived from naturally converted energy, is not entirely controllable. Although controllers exist, the condition of the batteries directly affects charging. Therefore, wind and solar energy storage batteries have an additional uncontrollable factor compared to other batteries, and this factor is particularly problematic. In fact, charge acceptance is a crucial parameter for lead-acid batteries, but it is even more important for energy storage batteries.
The power output of solar panels or wind turbines is generally limited and cannot be very high. Batteries must store this limited energy, which depends on the battery's charging performance. More importantly, the charging acceptance of lead-acid batteries is related to their lifespan; poor charging acceptance directly affects the battery's lifespan.
