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EcoFlow DELTA 3 Smart Extra Battery — 1024Wh LFP Expansion

Double Your Storage for Grid-Independent Power

1024Wh LFP storage — Adds a full kWh to your DELTA 3 system
4,000-cycle lifespan — Roughly 10 years of daily use at 80% capacity
Zero-setup stacking — Plug in and stack — no wiring or configuration
App-monitored status — Track charge, time, and hours via EcoFlow app
  • FREE System Design Consultation -- Engineers size your battery bank for your actual consumption
  • FREE Shipping -- Free shipping on all orders

$358.95

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EcoFlow DELTA 3 Series Smart Extra Battery
EcoFlow DELTA 3 Series Smart Extra Battery
$358.95

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In the box

  • EcoFlow DELTA 3 Smart Extra Battery
EcoFlow DELTA 3 Series Smart Extra Battery
EcoFlow DELTA 3 Smart Extra Battery — 1024Wh LFP Expansion
$358.95

Double Your Storage for Grid-Independent Power

Add 1024Wh to your DELTA 3 Plus or DELTA 3 power station and double your storage for grid-independent living. This LFP extra battery delivers 4,000 cycles to 80% capacity — roughly a decade of daily off-grid use — outlasting similar-capacity lithium-ion units by six times. At 1/3 smaller than the DELTA 2 equivalent, it stacks securely on top of your power station to save space. Zero setup: just plug in, then monitor charge status, remaining time, and hours left via the built-in screen or EcoFlow app.

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LFP Battery Chemistry
4,000 Cycle Lifespan
Stackable Compact Design
App & Screen Monitoring
1024 Wh
Added Capacity
4,000
Cycles to 80%
21.1 lbs
Net Weight
LFP Chemistry That Outlasts the Competition

LFP Chemistry That Outlasts the Competition

Most portable power stations use NMC cells that degrade after 500 to 800 cycles — meaning you are replacing the battery in two to three years. The DELTA 3 Smart Extra Battery uses LFP chemistry rated for 4,000 cycles to 80% capacity. That is roughly a decade of daily use. At Off Grid Vault, we vet every battery for real-world cycle life because we have seen too many buyers burn money on chemistry that cannot handle sustained off-grid or backup duty. This is the same cell chemistry used in serious home solar banks — now in a compact, stackable expansion unit.

Plug In, Stack, and Keep Going

Plug In, Stack, and Keep Going

No wiring, no configuration, no guessing whether this battery will talk to your power station. The DELTA 3 Smart Extra Battery connects through a dedicated Extra Battery Port and stacks directly on top of your DELTA 3 Plus or DELTA 3 unit — one-third smaller than the DELTA 2 version it replaces. You get 1024Wh of additional storage instantly. Monitor battery percent, remaining recharge time, and hours left on the built-in screen or through the EcoFlow app. Recharge the whole stack from AC outlets, portable solar panels, or a Smart Generator through the main unit. It is off-grid proven simplicity for anyone who has already committed to building a real power system.

Scale Storage for Real Outage Duration

Scale Storage for Real Outage Duration

A single power station might get you through eight to twelve hours. When the grid drops for three days, you need more than that. Adding a DELTA 3 Smart Extra Battery doubles your DELTA 3 Plus capacity to 2048Wh — enough to keep a refrigerator, lights, and communications running through an extended outage. At 21.1 lbs and 15.7 by 8.0 by 7.8 inches, it fits in an RV, a cabin corner, or a garage backup station. This is field-tested storage expansion for anyone who has calculated their kWh-per-day consumption and knows a single unit will not cover it. Add one, add two — build the bank your actual load demands.

Compatibility Check

This extra battery connects to specific EcoFlow power stations only. Verify your unit before ordering.

  • Your power station is a DELTA 3 Plus, DELTA 3, DELTA 3 (1500), or DELTA 2
  • Your power station has an available Extra Battery Port
  • You have at least 15.7 in × 8.0 in of flat surface for secure stacking

Built for Real-World Scenarios

Expand your energy reserves wherever you need reliable, field-tested backup power.

Home Backup Power
RV & Van Life
Off-Grid Cabins

Full specifications

At a glance

Dimensions
15.7*8.0*7.8in
Warranty
See product page
Full specifications9 data points across 4 categories

Dimensions

Dimensions15.7*8.0*7.8in
Net Weight21.1 lbs

Power & Performance

Capacity1024 Wh
OutputExta Battery Port, 40V-58.4V 48A MAX
InputExtra Battery Port, 40V-58.4V 24A MAX
Cycle Life4000 Cycles to 80%

Materials

Battery ChemistryLFP

Compliance & Warranty

CompatibilityDELTA 3 Plus/ DELTA 3/ DELTA 3 (1500)/ DELTA 2
WarrantySee product page

The Off Grid Vault Promise

Every product we carry is vetted for real-world performance. If it doesn't meet our standards, it doesn't make the cut.

30-Day Performance GuaranteeIf it doesn't perform as specified, we make it right — uninstalled, in original packaging.
Free ShippingShips free on all orders, no minimums, no surprise freight charges.
Authorized DealerWarranty claims go through us — not through a faceless ticket queue.
★★★★★
“I added two of these to my DELTA 3 Plus for my cabin in northern Arizona. Went from worrying about a single night of backup to having confidence through a three-day outage. The stacking design is clean — no cables running everywhere. LFP was the deciding factor for me. Ten years of cycle life is real value.”
F
First L.Flagstaff, AZ

DELTA 3 Series Smart Extra Battery

Increase The Capacity Of DELTA 3 Plus/DELTA 3 With An Extra 1024Wh. Double The Capacity To Fit Your Energy Storage Needs, Ideal For Home Backup, RVingOutdoor Adventures, And Everyday Use. With The Compact Design, The DELTA 3 Smart Extra Battery Is1/3 Smaller Than Its
DELTA 2 Counterpart. It Can Also Be Securely Stacked On Top Of The Power Station To
Save Space And Minimize Clutter.

With The LFP Battery Chemistry, The DELTA 3 Smart Extra Battery Has A Lifespan Of 4000 Complete Cycles Until 80% Capacity. You’ll Get Pretty Much 10 Years Of Power, Even If You Use It Every Day. That’s 6x Longer Than Other Power Stations With A Similar Capacity And Output.

There’s No Setup. Just Plug Into Your Power Station For More Energy Storage. Using The EcoFlow App, You Can Charge And Monitor The DELTA 3 Smart ExtralBattery With Ease.

Get All The Same Info About Battery Percent, Remaining Recharge Time, Hours Left, And More On The Built-In Screen. You Can Check The Battery’s Status Right From The EcoFlow App.

Connect The Extra Battery To The Power Station’s Extra Battery Port/And Recharge From AC Outlets, Portable Solar Panels, Or Our Smart Generator.


EcoFlow DELTA 3 Extra Battery Specs

DELTA 3 Extra Battery

  • Dimensions: 15.7*8.0*7.8in
  • Net Weight: 21.1 lbs
  • Capacity: 1024 Wh
  • Output: Exta Battery Port, 40V-58.4V 48A MAX
  • Input: Extra Battery Port, 40V-58.4V 24A MAX
  • Battery Chemistry: LFP
  • Cycle Life: 4000 Cycles to 80%
  • Compatibility: DELTA 3 Plus/ DELTA 3/ DELTA 3 (1500)/ DELTA 2


Your Satisfaction with EcoFlow is Guaranteed:

  • Lowest Price Guarantee
  • Limited 5 Year Warranty

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Frequently Asked Questions

The DELTA 3 Smart Extra Battery works with DELTA 3 Plus, DELTA 3, DELTA 3 (1500), and DELTA 2 power stations. It connects through the dedicated Extra Battery Port — no adapters, no mismatched voltages. If you are running a DELTA 2, you can still expand, but the DELTA 3 form factor is one-third smaller and uses the newer LFP chemistry for longer cycle life. Check your unit model before ordering, or reach out to us and we will confirm compatibility.
The number of extra batteries you can connect depends on your specific DELTA 3 model and its supported expansion limit. Check your power station manual for the exact maximum. At Off Grid Vault, we offer free system design consultation — tell us your daily kWh consumption and your base unit model, and we will calculate exactly how many extra batteries your setup requires. No guesswork, no over-buying.
LFP — lithium iron phosphate — delivers 4,000 cycles to 80% capacity. Standard lithium-ion NMC cells typically manage 500 to 800 cycles before significant degradation. For a backup battery that you cycle daily or weekly, LFP means roughly ten years of usable life versus two to three years from NMC. LFP also runs cooler, has a wider safe operating temperature range, and is less prone to thermal runaway. At Off Grid Vault, we specifically vet for LFP chemistry in expansion batteries because we know our buyers are building systems meant to last, not disposable units.
No. The DELTA 3 Smart Extra Battery recharges through your DELTA 3 or DELTA 3 Plus power station. You charge the main unit from AC outlets, portable solar panels, or a Smart Generator, and the extra battery charges in parallel through the Extra Battery Port connection. The EcoFlow app and built-in screen show charge status for both the main unit and the extra battery so you always know where your storage stands. This integrated approach ensures the charge controller manages both batteries correctly.
At $358.95 for 1024Wh of LFP storage with a 4,000-cycle rating, you are paying roughly $0.35 per Wh across a decade of use. Compare that to replacing a shorter-lived NMC battery two or three times over the same period. For a homesteader or prepper who has already invested in a DELTA 3 system, this is not a speculative purchase — it is a calculated expansion of proven storage. Free shipping is included on every order.
Off Grid Vault offers a 30-day performance guarantee. If the battery does not perform as specified — 1024Wh capacity, proper LFP cycling, clean communication with your DELTA 3 unit — return it uninstalled in original packaging for a full refund. We are an authorized EcoFlow dealer, so any warranty claim after the 30-day window goes through us directly, not through a faceless ticket queue. You are not buying from a generic marketplace — you are buying from a store that stands behind every cell and every spec.
SKU: EFDELTA3P-EB Category: Brand:

The Off Grid Vault Promise

Every product we carry is vetted for real-world performance. If it doesn't meet our standards, it doesn't make the cut.

30-Day Performance Guarantee If it doesn't perform as specified, we make it right — uninstalled, in original packaging.
Free Shipping Ships free on all orders, no minimums, no surprise freight charges.
Authorized Dealer Warranty claims go through us — not through a faceless ticket queue.

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About ecoflow Expansion Batteries

ecoflow is a trusted manufacturer of premium expansion batteries. OffGridVault is an authorized dealer offering the full ecoflow lineup with free delivery, price match guarantee, and expert support.

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