The cost of battery storage per kWh ranges from $700 to $1,300 installed for residential systems and $125 to $334 for utility-scale projects as of late 2025. Battery pack prices alone have dropped to a record low of $70-$108/kWh, representing a 93% decline over the past. Lithium Iron Phosphate (LFP) has become the gold standard for stationary storage due to its safety profile and long cycle life. While Nickel Manganese Cobalt (NMC) was once dominant, the lower cost of LFP has helped drive down the overall market price. This article presents clear. In this work we describe the development of cost and performance projections for utility-scale lithium-ion battery systems, with a focus on 4-hour duration systems. The main cost drivers are the type of chemistry, the system size, balance-of-system components, installation, and local permitting. Below are practical ranges to help buyers estimate. In 2025, the typical cost of a commercial lithium battery energy storage system, which includes the battery, battery management system (BMS), inverter (PCS), and installation, is in the following range: $280 - $580 per kWh (installed cost), though of course this will vary from region to region.