ZeroRPM energy modules are a safe and space efficient solution when you want to add lithium power to your vehicle. This module is designed to power lights, radios, computers, inverters and other electronics with your engine off. Energy Modules of the same voltage may be added in parallel to increase the run time of your system. Energy modules contain an on-board battery management system. ZeroRPM energy modules use lightweight *lithium-iron batteries. This chemistry makes ZeroRPM battery technology among the safest on the market. This unit can be charged using 24V power from an alternator, solar panels, or other 24V power source.