How is the battery life span estimated as it is dependent on the depth of discharge cycle?

HOMER assumes that the battery dies after a certain amount of energy has cycled through it.  We use the term ‘lifetime throughput’ for that quantity of energy.  If that assumption is true, then it doesn’t matter how many times the battery cycles down to 75% state of charge or 50% state or charge.  All that matters is how many kWh have cycled through the battery.

Please look up ‘battery lifetime throughput’ in the index of the Help file for information on how HOMER calculates that value, and the lifetime of the battery bank.