Lead Acid Batteries Lead acid batteries are among the longest-used and most reliable batteries in existence. They are the cheapest option but you trade cost for battery life and depth of discharge. But for homeowners needing lots of storage for a lower cost, or if you are just making the move to a solar system, lead acid may be a very good option. Saltwater Batteries Saltwater batteries are more expensive than lead acid batteries, but also have a greater lifespan. Unlike lead acid batteries, saltwater batteries are essentially brand new to the market and remain both somewhat untested and harder to come across. Of the three types of batteries, saltwater has the greatest depth of discharge, so you’ll get the most output per charge before needing to recharge. Lithium Batteries Lithium batteries are the most expensive and the longest lasting of the three types of solar batteries. Their depth of discharge is less than that of a saltwater battery, but more than that of a lead acid battery. Comparing all three options, the lithium battery is probably the highest rated, but also the least accessible cost-wise. View our Free Presentation to learn how to bring old batteries back to life again