Kastar Ni-CD Battery 6V 2800mAh Replacement for Streamlight SL20, SL20X, SL20S, SL20XP LED, SL20X-LED, SL-20XP-LED, 20170, 201701, 20175, 15X1701, 20X1701 Flashlights - Batteries And Power Supplies - Amazon.com
Any means to upgrade an old Streamlight SL20? : r/flashlight
Streamlight SL-20X LED Flashlight
Streamlight SL-20X Rechargeable Flashlight with 120V AC Charger and 2 Charging Sleeves - LED and Halogen Bulbs - 200 Lumens - Includes NiCd Battery Pack (20203)