With the EcoFlow patented X-Stream Technology, the smart inverter enables a fast rechargeability. Even after adding the Extra Battery to RIVER, recharging time from AC wall outlet of the combined unit remains the same, with less than 1 hour to charge from 0%-80%, and fully charged in 1.6 hours from an AC wall outlet. Harness greater capacity Attach the additional battery to RIVER and harness a doubled capacity of 576Wh from 288Wh. To install, use the screwdriver from the module tool kit to secure the additional battery to RIVER. A storage upgrade for less If youâre looking to upgrade RIVER, adding an additional battery gives you double the capacity for less. All the while, RIVERâs BMS monitors your battery to keep it safe. Lightning-fast charging Even with an additional battery, the speed of charging RIVER from a standard plug socket is the same. With 0-80% charge in under 60 minutes and full charge in 1.6 hours, you wonât even notice the additional battery there. This is all thanks to EcoFlowâs X-Stream technology. Power more devices With doubled capacity coupled with RIVERâs X-Boost mode, you can power devices up to 1800W. This should cover you for home appliances and in some cases, power tools.