@dschind the battery is a simple single cell 3V Li Ion coin cell with solder tabs. Something like a Panasonic VL2020 or the ML2020 Looks like [https://www.digikey.com/en/products/detail/panasonic---bsg/ML-2020%2FH1CN/416290?utm_adgroup=&utm_source=google&utm_medium=cpc&utm_campaign=PMax%20Shopping_Product_Low%20ROAS%20Categories&utm_term=&utm_content=&utm_id=go_cmp-20243063506_adg-_ad-__dev-c_ext-_prd-416290_sig-Cj0KCQiAyKurBhD5ARIsALamXaGZ-gRwA8SUsJ2cmUtZ0WKPPbvP3Idji1oupwK0t6tWAXWMlMaJrTcaAp3XEALw_wcB&gad_source=1&gclid=Cj0KCQiAyKurBhD5ARIsALamXaGZ-gRwA8SUsJ2cmUtZ0WKPPbvP3Idji1oupwK0t6tWAXWMlMaJrTcaAp3XEALw_wcB|this one]. It is soldered to the battery controller. Yes, you can replace this pretty easily yourself for as long as you have some experience soldering. If you tear the outside wrapping of the battery assembly, simply get some kapton tape to replace that after the battery replacement.