If you want the portable battery powered aspect of the Amazon Tap, but don’t want to give up the always-listening functionality and superior sound of the Amazon Echo, then the Battery Boot may be for you. Battery Boot is a new 3rd-party accessory for the Amazon Echo, which began shipping to customers this week, that simply adds a battery to the bottom of the device. There are three models available, which range between 6 hours of battery life for the least expensive model, to 14 hours of battery life for the top model. Pricing starts at $69.99 for the low end EcoBoot, and climbs to $99.99 for the top tier MegaBoot. The least expensive Battery boot uses the Echo’s standard power cable to charge, while the middle and high end models come with a separate charging cable. With all models, the Echo can be used while the Battery Boot is charging. The Battery Boot is not compatible with the Echo Dot, since that uses a micro USB cable to charge and the Echo uses a round power port.