I have a CP1500AVR from 2013. I think it's had two battery replacements. Still going. I don't trust it to deal with aging batteries well. Just like my CP1000PFCLCD it tends to get very hot with aged batteries. My solution has been having them placed under my desk in a way that I can feel them with a bare foot. Excessive temps let me know it's time to replace. Usually 4-6 years in practice.