EcoFlow DELTA 3 Series Smart Extra Battery

Name: EcoFlow DELTA 3 Series Smart Extra Battery
Brand: EcoFlow
Price: 389 USD
Availability: InStock

1,024 Wh of LiFePO4, for the DELTA 3, DELTA 3 Plus and DELTA 3 Max Plus. $389 at EcoFlow, checked Oct 14, 2026: $0.38 for each watt-hour it adds.

Adds

1,024Wh

Price

$389

Per Wh added

$0.38

Each watt-hour it adds costs less than the stations' own ($0.58 on the DELTA 3, $0.70 on the DELTA 3 Plus and $0.56 on the DELTA 3 Max Plus), so it is the cheaper way to more stored energy than a second station, which adds outlets and output instead.

From EcoFlow's published figures and our own arithmetic; we have not tested it ourselves.

See it at EcoFlow Extra batteries for every station

Which stations take it

The most one station takes is EcoFlow's figure; a dash where its page gives none. Prices are both makers' prices added up, before cables.

EcoFlow DELTA 3 Series Smart Extra Battery on each station
Station	Most per station	With one	With the most	Station and one battery
EcoFlow DELTA 31,024 Wh on its own	–	2,048 Wh	–	$988
EcoFlow DELTA 3 Plus1,024 Wh on its own	–	2,048 Wh	–	$1,108
EcoFlow DELTA 3 Max Plus2,048 Wh on its own	–	3,072 Wh	–	$1,538

Specs

EcoFlow DELTA 3 Series Smart Extra Battery: EcoFlow's figures
Capacity	1,024 Wh
Cells	LiFePO4
Weight	not published
Cable, in the maker's words	not named on the page

Where these figures come from

EcoFlow product page: "Increase The Capacity Of DELTA 3 Plus/DELTA 3 With An Extra 1024Wh." · "With The LFP Battery Chemistry, The DELTA 3 Smart Extra Battery Has A Lifespan Of"
On the DELTA 3: EcoFlow's page, "Increase The Capacity Of DELTA 3 Plus/DELTA 3 With An Extra 1024Wh."
On the DELTA 3 Plus: EcoFlow's page, "Increase The Capacity Of DELTA 3 Plus/DELTA 3 With An Extra 1024Wh."
On the DELTA 3 Max Plus: EcoFlow's page, "DELTA 3 Max Plus works with: DELTA 3 Max Plus Smart Extra Battery, DELTA Pro 3 Smart Extra Battery, DELTA 3 Smart Extra Battery,"
Price and stock: EcoFlow's US store, checked Oct 14, 2026.