For everyone buying a Ring Video Doorbell 2 from the Costco deal, I found Ring selling the battery for $20 + tax. Shipping is free and you can checkout with Paypal or Amazon. Good deal when compared to normal price of $29 currently at Home Depot or Best Buy. I bought the Doorbell 2 from Costco today and it's very easy to swap it out. Although the wires from your doorbell should trickle charge the original battery, it's always handy to have a spare around especially since these can be charged by micro USB outside of the the camera.