CTEK's CS FREE is the world's first multi-functional portable battery charger and smart maintainer with Adaptive Boost technology. You can charge and maintain any 12V lead acid or lithium battery anywhere using a power outlet, solar or leisure battery power. If your battery's dead, CS FREE's revolutionary Adaptive Boost technology will work out the safest and quickest way to power up your battery to get you going within 15 minutes. Use it as a portable charger to top off your battery plugging into a power outlet, or hook it up to a solar panel kit or 12V battery for complete charging freedom anywhere you go. CS FREE also features our revolutionary Adaptive Boost technology so if your vehicle won't start, just connect it up and CS FREE will automatically analize the state of your battery. The CS FREE will work out the safest and quickest way to give the battery the power it needs to start your vehicle within 15 minutes. Unlike most ‘boosters', CS FREE is sensitive and safe, avoiding damage to your battery or vehicle's electronics by only giving it the charge it needs to get you going. CS FREE is also a smart maintainer and hi-tech powerbank to keep your battery and tech powered up so they're always ready to go.