5A DC-DC Step Up Power Module Boost Volt Converter 3-35V to 5V 6V 9V 12V 24V 36V | eBay
Amazon.com: DC-DC Buck Converter Step Down Module, DC 6.5V-60V to 1.25-30V Maximum 10A Adjustable Power Supply Voltage Regulator Module, Voltage Step Down Converter Board : Electronics