DIY: Ni-Cd To Lithium Battery Conversion By Using 18650 Cells - YouTube
Li-Ion battery 18650 2600 mAh with Micro-USB charging socket - ANSMANN AG
Amazon.com: Tenergy 2200mAh Sub C NiCd Battery for Power Tools, 1.2V Flat Top Rechargeable Sub-C Cell Batteries with Tabs, 15-Pack : Health & Household