Lifespan of solar batteries depends on the type and individual usage of the batteries. Basically, for lead acid batteries have lifespan of up to 3-7 years depending on the battery brands. Also, the usage of the batteries determines their life span, i.e. lead acid batteries should not be drained above 50% DOD and should be maintained regularly as stated by the manufacturer. If the systems owner violates these, lead acid batteries as a result have lower lifespan.Lithium-ion batteries have longer lifespan of up to 10-15 years depending on the battery brand and usage. These batteries have longer lifespan and more cycles as compared to lead acid batteries.