I have one of those key code front door dead bolts. Normal throw away Duracell type batteries were going dead every 4 months or so. I purchased these Panasonic batteries in March last year, I finally put them to use in April 2017 and they are still not dead. By the sound of the deadbolt moving I would say I am about 3-4 weeks away from having to recharge them. I researched rechargeable batteries and these came up as some of the best reviewed.
I purchased 4 of them with a wall charger for $22
https://www.amazon.com/gp/product/B00JHKSL1O/ref=oh_aui_search_detailpage?ie=UTF8&psc=1
Then purchased 4 more for an additional 4 batteries so I can just swap as needed for $20 more.... I know, the charger was only $2. I shoudl have just purchased two of the $22 packages.
https://www.amazon.com/gp/product/B00JHKSL28/ref=oh_aui_search_detailpage?ie=UTF8&psc=1