The EcoFlow DELTA Max Smart extra battery doubles the capacity when connected to a DELTA Max portable power station. This can have the effect of you increasing the batteries capacity from 2016Wh (standard) to 6048Wh (DELTA Max x 2 Smart Extra Batteries). DELTA Max Smart extra battery Capacity: 2016Wh. Features: Battery capacity 2016Wh Doubles the capacity of the EcoFlow DELTA Max Can increase the batteries capacity from 2016Wh to 6048Wh (x2) Silent & zero emissions rechargeable lithium-ion battery Fast charging via mains, 12v car adapter or solar panel (optional) Specifications: Dimensions: H:28.2 x W:46.5 x D:23.6 cm Colour: Black Guarantee:2 years Material: Plastic Casing / Aluminium Chassis Model Number: ECODMEB