It Just Got Easier to Convert Lithium-Ion Battery Voltage to 3.3V with this Efficient Single Inductor Synchronous Buck-Boost Regulator | Analog Devices
2x 3.3V LiFe Battery 3300mAH to Tria TRH25 laser SunKing Pro solar light 26x65mm 694090632243 | eBay
A123 Systems rechargeable Li-Fe battery; 3.3v 2300mAh — Batteries America
Vape Gear Twist Cube 3.3V - 4.8V Adjustable Battery With Preheat Mode & USB Adapter - Display of 12 | Pen Style Batteries | Midwest Distribution
28 A123 System ANR26650M1B LiFePO4 26650 3.3V 2500 mAh Battery LiFe | eBay
9V Battery Step-Down Power Supply – ee-quipment.com