Older converters will limit battery life because they charge slowly and keep charging after the battery bank is full. Batteries that are kept on a charge after they are full will gas too fast and dry up.
Longer battery life can be expected with newer converters that have 3 or 4 stage chargers. These types of converter/chargers will charge with a higher bulk charge when the batteries are low and then change to an absorption mode to top off the battery then go into a float charge to maintain the proper voltage.
Some converters now have another stage that automatically equalizes the cells periodically.
These newer converters allow you to run your gas generator less by charging batteries quicker.
