Originally Posted by Maine Sail
There are very few boats today over 30 feet that can get away with a single 60 pound/100Ah battery, (35 usable Ah's when cruising), and not be replacing it every other year or sooner. People are simply using a lot more power today than they did even 10 years ago..
I'm sure this is true. However one thing in the back of my mind when discussing/reading bank life discussions is - does it matter?
At the end of the day batteries, especially lead acids are actually pretty cheap compared to everything else on a boat. If for space or weight reasons you don't want to add batteries it's not unreasonable in my opinion to decide that you'll just replace them every 2 or 3 years.
Personally I expect to get plenty of life out of my batteries and put a lot of thought into my system. But with $120 of batteries compared to ~4k fixed yearly expenses plus maintenance and discretionary it's not going to matter a lot in the big picture.