I purchased the Ring 2 from Costco just over 6 months ago. Install was fine, charged battery overnight before install. Battery life showed 99%. I recently noticed I was down to 16%, and removed and charged the battery as per instructions. After 8 hrs on the charger, I can not get the battery to read more than 37%. Is this a known issue, as it appears I will need a new battery shortly. Thank you for any help/suggestions.