Innovative technology with no internal battery so no need to wait hours for the unit to charge before use. Simple and safe to use with no long term battery storage issues. Can be fully energised in approximately 2 minutes. If the vehicle battery is faulty or is holding less than 5 volts the E/START800 can be pre-charged via another vehicle's battery, the supplied Micro USB charging cable or the 12V accessory lead. Compact and lightweight for easy handling and storage, yet still delivers the same result as heavy, bulky, lead acid battery equivalents. Ideal for the professional mechanic and DIY users.