Amazon.com: Car Battery Jump Starter - 1800 Amp 12V 24V Heavy Duty Jump Box, Works with Truck Tractor Excavator Automotive Engine Starter Battery Charger Booster Jumper Box with USB/DC Power Unit :
NOCO - 6250A Lithium Jump Starter - GB500+
Dave's Bus Conversion - 12V on 24V converters - 24V to 12V conversion
FreeEnergy 12V/24V DC Permanent Magnet Motor PMA for Wind Turbine Generator 350W | eBay
12V to 24V 100A 2400W DC DC Step Up Converter Voltage Regulator – Daygreen
UCTRONICS DC 6V 9V 12V 24V to DC 5V 5A Buck Converter Module, 9-36V Step Down to USB 5V Transformer Dual Output Voltage Regulator Board [2 Pack]
What Is a 12V to 24V Converter? | Battle Born Batteries
12V vs 24V: What's The Difference In Battery Systems?