It depends on the battery. Through trial and error, I discovered that I wasn't gaining much by spending over $100 on a battery. I now look for discounts at the end of the season at big box stores and haven't spent over $50 on a battery in a long time (this goes for everything I have with an engine). With that being said, batteries, like engines, like to be used. For the short amount of time it takes me to pull the battery and keep it out of sub zero temperatures and throw on a $7 float charger, it is a no brainer to pull it for me. Goes in the heated garage on a float charger and my $45 battery lasts me 5-7 years. As I got to know my boat and engine, I could tell when the battery started to lose its life and out it went.