Increase your home energy storage capacity with the Yeti Link Expansion Module and Yeti Tank Expansion Battery (sold separately). Yeti Link lets you connect Yeti Tank lead-acid batteries to your Yeti X or Yeti Lithium Power Station to increase your storage capacity at 1.2 kWh intervals. The Yeti Link comes with its own 120W Power Supply for charging from the wall. Usage Note: The Yeti Link Expansion Module and Yeti Lithium MPPT Solar Charging Optimization Module use the same expansion bay therefore they are unable to be used at the same time.