Prices are checked against each store and labelled with when. Store links may earn us a commission. Price via Klarna.
It checks today's price at every store, compares the alternatives and answers in about a minute.
The EcoFlow RIVER 3 Plus Smart Extra Battery is a 286Wh LiFePO4 expansion pack that stacks onto the RIVER 3 Plus portable power station to roughly double its runtime. It adds its own USB-C port with USB-PD and up to 140W output, so it can also charge laptops and phones on its own. The only new price listed is $208.99 at Best Buy as of November 7, 2026, with no other new-store prices to compare against.
In stock
Store links may earn us a commission. Price via Klarna.
Lowest price we've seen: $208.99 on Nov 7 at Best Buy. Tracked across 1 store since Nov 7.
Owner feedback on EcoFlow's RIVER expansion batteries is generally positive on build and capacity gains, with the main complaints about cost per watt-hour and the need to buy into the same ecosystem.
