EcoFlow DELTA Pro 3 Smart Extra Battery

Name: EcoFlow DELTA Pro 3 Smart Extra Battery
Brand: EcoFlow
Price: 1899 USD
Availability: InStock

4,096 Wh of LiFePO4, for the DELTA Pro 3, DELTA 3, DELTA 3 Plus, DELTA 3 Max Plus and DELTA 3 Ultra Plus. $1,899 at EcoFlow, checked Oct 14, 2026: $0.46 for each watt-hour it adds. With the 2 EcoFlow allows, the DELTA Pro 3 holds 12,288 Wh in all.

Adds

4,096Wh

Price

$1,899

Per Wh added

$0.46

Each watt-hour it adds costs less than the stations' own ($0.68 on the DELTA Pro 3, $0.58 on the DELTA 3, $0.70 on the DELTA 3 Plus, $0.56 on the DELTA 3 Max Plus and $0.52 on the DELTA 3 Ultra 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 Pro 3 Smart Extra Battery on each station
Station	Most per station	With one	With the most	Station and one battery
EcoFlow DELTA Pro 34,096 Wh on its own	2	8,192 Wh	12,288 Wh	$4,698
EcoFlow DELTA 31,024 Wh on its own	–	5,120 Wh	–	$2,498
EcoFlow DELTA 3 Plus1,024 Wh on its own	–	5,120 Wh	–	$2,618
EcoFlow DELTA 3 Max Plus2,048 Wh on its own	2	6,144 Wh	10,240 Wh	$3,048
EcoFlow DELTA 3 Ultra Plus3,072 Wh on its own	2	7,168 Wh	11,264 Wh	$3,498

Specs

EcoFlow DELTA Pro 3 Smart Extra Battery: EcoFlow's figures
Capacity	4,096 Wh
Cells	LiFePO4
Weight	33 kg (72.8 lb)
Cable, in the maker's words	"EcoFlow Extra Battery Cable"

Where these figures come from

EcoFlow product page: "4096Wh" · "33kg" · "Built with state-of-the-art automotive-grade LFP cells for safe and reliable service."
On the DELTA Pro 3: EcoFlow's page, "12kWh (2 × DP3 Extra Battery)"
On the DELTA 3: EcoFlow's page, "Support DELTA 2 EB, DELTA 2 Max EB, DELTA Pro 3 EB, and DELTA 3 EB (Up to 5kWh)"
On the DELTA 3 Plus: EcoFlow's page, "Supports the following Extra Battery models via an Alternator Charger XT150 Output Cable: DELTA 3 Extra Battery, DELTA 2 Extra Battery, DELTA 2 Max Extra Battery, and DELTA Pro 3 Extra Battery."
On the DELTA 3 Max Plus: EcoFlow's page, "Require connecting 1 × DELTA 3 Max Plus + 2 × DELTA Pro 3 Smart Extra Battery"
On the DELTA 3 Ultra Plus: EcoFlow's page, "Require connecting 1*DELTA 3 Ultra Plus (3072Wh) + 2* DELTA Pro 3 Smart Extra Battery with EcoFlow Smart Extra Battery Expansion Adapter."
Price and stock: EcoFlow's US store, checked Oct 14, 2026.