Pentax D-LI109 Battery (2-Pack) and Dual Charger by Wasabi Power
Amazon.com : Glorich K-AC128 D-AC128 K-AC109 K-AC168 D-DC128 Replacement AC Power Adapter Kit for Pentax K30 K50 K70 K-r K2 K-S1 and K-S2 Digital SLR Cameras,D-Li109 Replacement(but not Compatible with Pentax KP) :
Amazon.com : D-LI109 Battery Charger for Pentax K-R, K-S1, K-S2, K-30, K-50, K-70, K-500 Digital SLR Digital Camera : Electronics
Source D-LI109 lithium battery for Pentax K-50 K-S1 K-30 KS2 K-R KR K500 k-2 DA40XS on m.alibaba.com
HQRP AA Battery Holder-Adapter for Pentax D-BH109 K-r K-30 K-50 K-500
Amazon.com : DSTE Replacement for D-Li109 Battery + DC112 Travel and Car Charger Adapter Compatible Pentax K-R K-30 K-50 K-500 KR K30 K50 K500 K-S1 K-S2 K-70 Camera : Electronics
Amazon.com: Pentax K-50 Digital Camera Battery Charger (110/220v with Car & EU adapters) - Replacement Charger for Pentax Dli-109 Battery - : Electronics
Kastar Battery LCD Quick Charger for Pentax D-Li109 D-BC109 & Pentax K-50 Camera | eBay
DLi109 D-LI109 D-BC109 Battery USB Charger for Pentax K-50 K50 K-30 K30 K-S1 KS1 K-S2 KS2 and K-r Kr DSLR Cameras - AliExpress