Charged Reviews
EcoFlow DELTA Pro 3 Smart Extra Battery: Product photo published by EcoFlow on its product page for "EcoFlow DELTA Pro 3 Smart Extra Battery".
Photo 1 of 1. 1 photo · Image from us.ecoflow.com
Photo sources

Manufacturer and seller images. Configuration examples may include additional equipment.

Image source: Product photo published by EcoFlow on its product page for "EcoFlow DELTA Pro 3 Smart Extra Battery".

EcoFlow DELTA Pro 3 Smart Extra Battery

By EcoFlowSKU not documented

Expansion batteryPortable expansion51.2 V80 Ah
Evidence score4/100Missing details
No reviews · Write the first
Write a review
from$1,899$464 / kWh
Price unchanged · 12 checks since Oct 27
$1,899 ($464/kWh) at ShopSolarView all sellers

Paid link · price checked

SaveReport an errorWrite a reviewQuick reference sheet
Basic specs4.1 kWh*Discharge100 ACharge80 A max.$ / rated kWh$463.62*WarrantyUnknownSee termsLifetime productionNot publishedSize43.98 L*W: 295 × H: 691.8 × L: 215.5 mm33 kg72.75 lb0.09 kWh/L*CertificatesNone on fileEvidence missing

Key specs

Units
Chemistry
LFP (LiFePO4)
Official user manual
Sources

Printed as "Cell Chemistry LFP (LiFePO4)" in the EcoFlow DELTA Pro 3 Smart Extra Battery user manual (Model EFD521-EB), Specifications, captured on September 26, 2026.

Official user manual: EcoFlow DELTA Pro 3 Smart Extra Battery_User Manual Checked · Earlier document

Location: Specifications

Documented

Nominal energy
4.1 kWh
Converted: 4096 Wh / 1000 = 4.096 kWh
Official user manual
Sources

Converted: 4096 Wh / 1000 = 4.096 kWh

Printed as "Capacity 80Ah 4096Wh" in the EcoFlow DELTA Pro 3 Smart Extra Battery user manual (Model EFD521-EB), Specifications, captured on September 26, 2026.

Official user manual: EcoFlow DELTA Pro 3 Smart Extra Battery_User Manual Checked · Earlier document

Location: Specifications

Converted

Nominal voltage
51.2 V
Official user manual
Sources

Printed as "Nominal Voltage 51.2V⎓" in the EcoFlow DELTA Pro 3 Smart Extra Battery user manual (Model EFD521-EB), Specifications, captured on September 26, 2026.

Official user manual: EcoFlow DELTA Pro 3 Smart Extra Battery_User Manual Checked · Earlier document

Location: Specifications

Documented

Rated capacity
80 Ah
Official user manual
Sources

Printed as "Capacity 80Ah 4096Wh" in the EcoFlow DELTA Pro 3 Smart Extra Battery user manual (Model EFD521-EB), Specifications, captured on September 26, 2026.

Official user manual: EcoFlow DELTA Pro 3 Smart Extra Battery_User Manual Checked · Earlier document

Location: Specifications

Documented

Continuous discharge current
100 A
Official user manual
Sources

Printed as "EcoFlow Proprietary Port 40V-58.4V⎓100A continues" in the EcoFlow DELTA Pro 3 Smart Extra Battery_User Manual (page 10, Technical Specifications, Output). Extra Battery Port output rating (printed as continuous).

Official user manual: EcoFlow DELTA Pro 3 Smart Extra Battery_User Manual Checked · Earlier document

Location: PDF page 10, Technical Specifications, Output

Documented

Maximum charge current
80 A
Official user manual
Sources

Printed as "EcoFlow Proprietary Port 40V-58.4V⎓80A Max" in the EcoFlow DELTA Pro 3 Smart Extra Battery_User Manual (page 10, Technical Specifications, Input). Extra Battery Port input rating.

Official user manual: EcoFlow DELTA Pro 3 Smart Extra Battery_User Manual Checked · Earlier document

Location: PDF page 10, Technical Specifications, Input

Documented

Cycle rating
4,000 cycles
80%+ SoH at 0.5C/0.5C, 25°COfficial user manual
Sources

Printed as "The battery maintains 80%+ SoH (State of Health) after 4000 cycles at 0.5C/0.5C at 25°C (77°F)" in the EcoFlow DELTA Pro 3 Smart Extra Battery user manual (Model EFD521-EB), Specifications, captured on September 26, 2026.

Official user manual: EcoFlow DELTA Pro 3 Smart Extra Battery_User Manual Checked · Earlier document

Location: Specifications

Documented

Battery weight
33 kg73 lb converted
Official user manual
Sources

Printed as "Net.Weight Approx. 33 kg (72.75 lb)" in the EcoFlow DELTA Pro 3 Smart Extra Battery user manual (Model EFD521-EB), Specifications, captured on September 26, 2026.

Official user manual: EcoFlow DELTA Pro 3 Smart Extra Battery_User Manual Checked · Earlier document

Location: Specifications

Documented

1 spec not documented yet: usable energyHelp fill in ›

All specs23
Chemistry
LFP (LiFePO4)
Official user manual
Sources

Printed as "Cell Chemistry LFP (LiFePO4)" in the EcoFlow DELTA Pro 3 Smart Extra Battery user manual (Model EFD521-EB), Specifications, captured on September 26, 2026.

Official user manual: EcoFlow DELTA Pro 3 Smart Extra Battery_User Manual Checked · Earlier document

Location: Specifications

Documented

Nominal energy
4.1 kWh
Converted: 4096 Wh / 1000 = 4.096 kWh
Official user manual
Sources

Converted: 4096 Wh / 1000 = 4.096 kWh

Printed as "Capacity 80Ah 4096Wh" in the EcoFlow DELTA Pro 3 Smart Extra Battery user manual (Model EFD521-EB), Specifications, captured on September 26, 2026.

Official user manual: EcoFlow DELTA Pro 3 Smart Extra Battery_User Manual Checked · Earlier document

Location: Specifications

Converted

Usable energy
Not documented
Nominal voltage
51.2 V
Official user manual
Sources

Printed as "Nominal Voltage 51.2V⎓" in the EcoFlow DELTA Pro 3 Smart Extra Battery user manual (Model EFD521-EB), Specifications, captured on September 26, 2026.

Official user manual: EcoFlow DELTA Pro 3 Smart Extra Battery_User Manual Checked · Earlier document

Location: Specifications

Documented

Rated capacity
80 Ah
Official user manual
Sources

Printed as "Capacity 80Ah 4096Wh" in the EcoFlow DELTA Pro 3 Smart Extra Battery user manual (Model EFD521-EB), Specifications, captured on September 26, 2026.

Official user manual: EcoFlow DELTA Pro 3 Smart Extra Battery_User Manual Checked · Earlier document

Location: Specifications

Documented

Continuous discharge current
100 A
Official user manual
Sources

Printed as "EcoFlow Proprietary Port 40V-58.4V⎓100A continues" in the EcoFlow DELTA Pro 3 Smart Extra Battery_User Manual (page 10, Technical Specifications, Output). Extra Battery Port output rating (printed as continuous).

Official user manual: EcoFlow DELTA Pro 3 Smart Extra Battery_User Manual Checked · Earlier document

Location: PDF page 10, Technical Specifications, Output

Documented

Maximum charge current
80 A
Official user manual
Sources

Printed as "EcoFlow Proprietary Port 40V-58.4V⎓80A Max" in the EcoFlow DELTA Pro 3 Smart Extra Battery_User Manual (page 10, Technical Specifications, Input). Extra Battery Port input rating.

Official user manual: EcoFlow DELTA Pro 3 Smart Extra Battery_User Manual Checked · Earlier document

Location: PDF page 10, Technical Specifications, Input

Documented

Cycle rating
4,000 cycles
80%+ SoH at 0.5C/0.5C, 25°COfficial user manual
Sources

Printed as "The battery maintains 80%+ SoH (State of Health) after 4000 cycles at 0.5C/0.5C at 25°C (77°F)" in the EcoFlow DELTA Pro 3 Smart Extra Battery user manual (Model EFD521-EB), Specifications, captured on September 26, 2026.

Official user manual: EcoFlow DELTA Pro 3 Smart Extra Battery_User Manual Checked · Earlier document

Location: Specifications

Documented

Lifetime production

Not published

Published claims and calculations are not independently tested lifetime output.

Published claims and calculations, not independent test results.

Documents

2 on file
  • PDF
    EcoFlow DELTA Pro 3 Smart Extra Battery_User ManualOfficialEcoFlowOfficial user manual
    Source details
    Revision
    Not stated
    Revision date
    Not stated

    Location: Specifications

    Retrieved

    EcoFlow's own user manual PDF. EcoFlow's online manual page https://manuals.ecoflow.com/us/product/delta-pro-3-smart-extra-battery?lang=en_US links this file. Specification values are the manufacturer's.

    Archived copies

    Archived copy of a document published by EcoFlow. Copyright retained by the publisher; kept for reference and verification only, no endorsement implied. To ask for its removal, email legal@chargedreviews.com.

    Archived backup Revision not recorded · 1.78 MB

    Archived copy, unaltered, kept as a record of what EcoFlow published. Original address: https://ecoflow-service-us-prod.oss-us-west-1.aliyuncs.com/cms/manual/1736503373228/EcoFlow%20DELTA%20Pro%203%20Smart%20Extra%20Battery_User%20Manual_en_20250110.pdf. Copyright and takedown

    Source first found
    This copy captured
    Archived
    File detailsOriginal source
    Pages
    11
    Embedded creation date
    Embedded modification date

    Embedded dates are file metadata, not independent proof of publication.

    SHA-256: 11d54fa0bd886e83b2f4b243e9f81bfa86090ee6f130e17d3a3ae4cabf3f92c6

    Open
  • WEB
    EcoFlow product page: EcoFlow DELTA Pro 3 Smart Extra BatteryEcoFlowOfficial product page
    Source details
    Revision
    Not stated
    Revision date
    Not stated

    Matched to the catalog record on an exact product-name match; the store publishes no variant SKU for this product.

    Location: Store variant SKU —; product handle delta-pro-3-extra-battery

    Retrieved

    Manufacturer-operated store product page, captured byte for byte with a plain HTTPS GET and a desktop user agent. It establishes what the manufacturer published at this URL on the access date for the exact store variant named in the locator: the specification table, the photo and the documents linked from the page. Marketing text, certification wording and stock state on the page remain manufacturer claims that were not independently verified, and no value on it was applied to any other model.

    Open

Archive and older revisions

Archive and older revisions0

Earlier revisions, archived captures and copies published by someone other than the manufacturer. Every one stays reachable.

Archived documents

EcoFlow DELTA Pro 3 Smart Extra Battery_User Manual

Archived copy of a document published by EcoFlow. Copyright retained by the publisher; kept for reference and verification only, no endorsement implied. To ask for its removal, email legal@chargedreviews.com.

Archived backup Revision not recorded · 1.78 MB

Archived copy, unaltered, kept as a record of what EcoFlow published. Original address: https://ecoflow-service-us-prod.oss-us-west-1.aliyuncs.com/cms/manual/1736503373228/EcoFlow%20DELTA%20Pro%203%20Smart%20Extra%20Battery_User%20Manual_en_20250110.pdf. Copyright and takedown

Source first found
This copy captured
Archived
File detailsOriginal source
Pages
11
Embedded creation date
Embedded modification date

Embedded dates are file metadata, not independent proof of publication.

SHA-256: 11d54fa0bd886e83b2f4b243e9f81bfa86090ee6f130e17d3a3ae4cabf3f92c6

Submit a document

Warranty

No warranty terms on file.

Sellers

Affiliate links below. As an Amazon Associate we earn from qualifying purchases. Affiliate disclosure

Amazon

4.1 (7)not verified

Sold by Amazon.com

Listing SKU B0D149GKCZ

$2,106.32Price as of Nov 10, 2026, 8:50 PM PST, may change
Visit sellerPaid link. As an Amazon Associate we earn from qualifying purchases.

SanTan Solar

No reviews

Listing SKU DELTAPRO3EB

$1,899The seller's link opens a different version than the one we recorded. Check the version on the seller's page.Recorded
Visit sellerPaid link.

ShopSolar

1 review

Listing SKU EFDELTAPRO3EB

$1,899Recorded
Visit sellerPaid link.

Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon.com at the time of purchase will apply to the purchase of this product.

CERTAIN CONTENT THAT APPEARS ON THIS SITE COMES FROM AMAZON. THIS CONTENT IS PROVIDED ‘AS IS’ AND IS SUBJECT TO CHANGE OR REMOVAL AT ANY TIME.

Report a seller problem

Price history

Prices we read at ShopSolar and SanTan Solar · 13 readings from to

Chart, listings & data

Since · Listing price (USD)

View listing at SanTan Solar Paid link.
View listing at ShopSolar Paid link.
$1,800$1,900$2,000SanTan Solar: $1,899 · Nov 4, 2026, 4:31 AM PSTShopSolar: $1,899 · Oct 27, 2026ShopSolar: $1,899 · Oct 28, 2026, 1:26 AM PDTShopSolar: $1,899 · Oct 30, 2026, 1:26 AM PDTShopSolar: $1,899 · Nov 1, 2026, 1:07 AM PDTShopSolar: $1,899 · Nov 3, 2026, 1:06 AM PSTShopSolar: $1,899 · Nov 4, 2026, 1:06 AM PSTShopSolar: $1,899 · Nov 5, 2026, 1:06 AM PSTShopSolar: $1,899 · Nov 6, 2026, 1:07 AM PSTShopSolar: $1,899 · Nov 7, 2026, 1:17 AM PSTShopSolar: $1,899 · Nov 8, 2026, 1:16 AM PSTShopSolar: $1,899 · Nov 12, 2026, 1:26 AM PSTOct 26, 2026Nov 12, 2026
ShopSolar$1,899Nov 12, 2026, 1:26 AM PSTLatest check · hover or tap for earlier prices

A break in a line is a gap in our readings: no price is drawn for days we did not read.

Price data
Collected price observations by seller
Checked (UTC)SellerPrice
Oct 27, 2026ShopSolar Paid link.$1,899
Oct 27, 2026, 1:07 AM PDTShopSolar Paid link.$1,899
Oct 28, 2026, 1:26 AM PDTShopSolar Paid link.$1,899
Oct 30, 2026, 1:26 AM PDTShopSolar Paid link.$1,899
Nov 1, 2026, 1:07 AM PDTShopSolar Paid link.$1,899
Nov 3, 2026, 1:06 AM PSTShopSolar Paid link.$1,899
Nov 4, 2026, 1:06 AM PSTShopSolar Paid link.$1,899
Nov 4, 2026, 4:31 AM PSTSanTan Solar Paid link.$1,899
Nov 5, 2026, 1:06 AM PSTShopSolar Paid link.$1,899
Nov 6, 2026, 1:07 AM PSTShopSolar Paid link.$1,899
Nov 7, 2026, 1:17 AM PSTShopSolar Paid link.$1,899
Nov 8, 2026, 1:16 AM PSTShopSolar Paid link.$1,899
Nov 12, 2026, 1:26 AM PSTShopSolar Paid link.$1,899

Owner reviews

No reviews yet

Own one? A verified review needs a receipt and a serial number photo, and counts 19× in the owner rating.

Write a review

Your reviews · Review policy

Evidence score

4/100Missing details20% documented

The Evidence score uses the priorities you choose. It counts published documents, such as certificates and warranty terms, and it compares a documented figure with the best documented figure of the same kind. It does not count owner reviews, and it is not a verdict on product quality or on how many people have reviewed it. A low score can mean little is documented, or that a documented figure is below the best of its kind. Undisclosed data scores 0.

Missing details. This number counts only the evidence recorded so far. The source review for this product is not finished, or the maker has not disclosed enough, so the number can only go up.

Missing for this product: Certificates evidence needed; Warranty term needed; Warranty energy disclosure evidence needed; Cell model disclosure evidence needed.

48 V · Portable expansion · Expansion · Rated capacity

The warranty term and the lifetime energy are each scored against the best documented value for an expansion battery: a value earns its share of that best, times the weight. A documented value always earns points; an undisclosed one earns 0.

Lifetime / capacity4,000 cycles4 / 20

Cycle rating disclosed · 20% weight

Documented cycle rating earns 20% of this criterion. More evidence is needed to compare lifetime MWh per kWh.

20 × 0.2 = 4 points.

Official user manual: EcoFlow DELTA Pro 3 Smart Extra Battery_User Manual Checked · Earlier document

Research pending, 0 points: Certificates, Warranty term, Warranty energy disclosure, Cell model disclosure.

Computed from public specifications and evidence records. Warranty duration is not service quality; certificate evidence points are not a safety rating. Compatibility and installation limits still apply.

How it works Manufacturer? Submit documentation

Certificates

No certificates on file. Certificate guide

Parts and accessories

No sourced accessories or replacement parts listed yet.

Model history

Model identity

Model
EFD521-EB

No historical observations recorded yet.

Community discussions

No discussions linked yet. Search DIY Solar Forum

Recalls / legal notices

No recalls or legal notices on file; this is not a complete recall or court search. All notices · Report a notice

EcoFlow logo
EcoFlowProducts, reviews and history
3.5 (18)

Something wrong that is not one of the values above?

Prices · price basis. * Calculated; estimates labeled. Value needs confirmation; select it for the reason.