Installed 7 units in 2018 March, have had 3 fail due to low battery, this is a sealed 10 year battery. First Alert is sending me a replacement. But I am concerned with product quality 3 defects out of 7 is a crazy defect level. I mentioned this to First Alert agent. I am not happy and do not want customers calling me with defect issues. I pushed on product quality. I also sent an email 3 or 4 months ago and received no reply from First Alert. Not sure if the company listens to Canadian customers.