The cost of a battery for storing solar energy varies depending on several factors, such as the battery's capacity, brand, technology, and the specific requirements of the system. In general, the cost of batteries has decreased in recent years, but it's important to consider the following aspects:

1. Battery capacity: Batteries are typically priced based on their storage capacity, expressed in kilowatt-hours (kWh). The larger the capacity, the more expensive the battery.

2. Type of battery technology: There are different types of battery technologies available, such as lithium-ion, lead-acid, etc. Lithium-ion batteries are generally more expensive, but they offer higher energy density and longer lifespan.

3. Brand and quality: Well-known brands with a good reputation can be more expensive, but they often offer better performance and reliability. The quality of the battery is an important factor in price determination.

4. Installation costs: In addition to the cost of the battery itself, you also need to consider installation costs. This includes the cost of the installer, wiring, and any adjustments to the solar energy system.

5. Subsidies and discounts: In some regions, there may be subsidies or discounts available that reduce the final cost of the battery.

To obtain specific price information, I recommend contacting solar energy system suppliers or installers. They can provide you with detailed quotes based on your specific needs and situation.