Capacity: The capacity of the battery should be sufficient to meet the power requirements of the inverter or solar system.
Warranty: Check that the warranties on the battery are no less than 10 years. Warranties on the Battery Management System (BMS) should be no less than 5 years.
Voltage: The voltage of the battery should be compatible with the voltage of the inverter or solar system.
Type: The type of battery should match the size and requirements of the inverter or solar system. Common types of batteries include lead-acid, lithium-ion and the best overall being LiFePO4 (Lithium-ion Phosphate)
Energy density: The energy density of the battery is an important consideration, as higher energy density batteries can be smaller and more efficient.
Cycle life: The number of cycles that the battery is designed to withstand is important as it determines the lifespan of the battery.
Brand reputation: The brand reputation of the manufacturer is important as it can determine the quality and reliability of the battery.
Price: The price of the battery should be reasonable in comparison to similar products of the same size and capacity.