The horror stories I've heard were the cheapies before the microprocessor controlled ones came out. I've got two schumachers right now at least 4 years old work perfectly. My brother is a believer, after purchasing his fourth sea doo, the dealer told him to use a battery tender. "It'll make your battery last longer" His comment "So why wasn't I told this for my first three 'doos?" Now mine won't charge a low battery, battery must have a good state of charge BEFORE hooking up the tender!
