Some upgrades and repairs on a sailboat are no-brainers. It’s not difficult know when you need new sails or the paint job and brightwork need attention. But figuring out if a battery upgrade is necessary and how to do it is at times less obvious. Odds are, though, that if the house batteries are more than five years old, you are going to want to think about replacing them. Wet-cell lead acid batteries have a life span of about five years. Some can be coaxed to perform longer, but their performance will degrade over time. If you’ve found that you are constantly charging the batteries or can’t run many of the systems you’d like to for long periods, it may be worth considering a battery upgrade as well.