I bought two of these in March of 2014. Totally maintenance free. Check terminals periodically for tightness and for any corrosion. I have a 3 bank charger that stays plugged in year round while the boat is parked. No more checking water levels. This is the same price I paid a year ago. They were packaged really well and arrived with no damage. Only time will tell if it was a good investment but so far so good.