Solar Charging
Users can connect solar panels in series as shown in the figure to recharge the product.
Solar charging cable (MC4-XT60 adapter cable) is supplied separately.
When using an EcoFlow solar panel to charge the product, please follow the instructions that come with the solar panel. Before connecting the solar panel, please ensure that the solar panel’s output voltage is within 60V to avoid product damage.
https://manuals.plus/ecoflow/delta-2-portable-power-station-manual#ixzz7qM2QKIsP