These are the only PWC batteries I will purchase.  My first one was over three years old and still working strong when I sold my Polaris.  I purchased two used Yamahas and this was the first thing I replaced for them.  What has worked extremely well for me is installing a perko switch and turn that puppy off when you're not using the battery.  It really extends the battery life.  I use on my boat and PWCs; especially in the off season and during the winter in storage.