Battery issues

Hi,Purchased the Ring Second Generation last week, after less than 24 hours the battery was at 30% and needing charged. I assumed I hadn't fully charged before installing.Put the unit on to charge on Saturday evening, went out for the night. On Sunday morning the unit was only at 40%. Continued to charge all day - at one point it reached 72% before immediately dropping to 50%. I changed cable and plug incase one was defective and the unit immediately showed XXXX% charge.This morning it's at 50%.Is this indicative of a faulty unit?ThanksScott