Home / Companion kits

Add-ons that make a system last longer

Companion products that actually earn their keep

These are the parts that make one system last longer or start a hard motor. Prices below are manufacturer or typical Amazon snapshots, dated beside each product where we have a check date (the DELTA 3 Series extra price is an older undated snapshot), and they will move. How-to pages walk through the same kits in order.

How extras attach How solar actually helps How to feed house circuits SHP3 notes

Four-step companion kit: portable, extra battery, solar panel, then house panel

1. Same-brand extra energy (buy these first)

EcoFlow DELTA 3 Series smart extra battery

DELTA 3 extra battery additional official angle

Manufacturer images · EcoFlow US 1 / 4

Entry extras

DELTA 3 Series extra

1,024 Wh add-on for DELTA 3 / Plus. Host required. Cheapest extra we can date.

Energy: 1,024 Wh
Host: DELTA 3 / DELTA 3 Plus
Standalone: No — extra pack only
Chemistry: LFP · 3,000+ cycles to 80% (page)
Warranty: 5 years (EcoFlow page)
Price snapshot: $389 sale / $499 list

View DELTA 3 extra on EcoFlow How extras attach

Manufacturer images · Anker SOLIX US 1 / 2

F3800 Plus extra

Anker SOLIX BP3800

3.84 kWh. Anker’s FAQ: it does not work alone.

Energy: 3,840 Wh
Host: F3800 Plus — does not run alone
Chemistry: LFP
Price snapshot: $1,799.99 Halloween sale / $1,999.99 list (checked 26 Oct 2026, sale ends 1 Nov 2026)

View BP3800 on Anker Compatibility notes

EcoFlow DELTA Pro Ultra X smart extra battery, front

Ultra X extra battery three-quarter with ports

Manufacturer images · EcoFlow US 1 / 3

6,144 Wh

Ultra X extra battery

Different SKU from DELTA 3 and DELTA Pro 3 extras. Pairs with Ultra / Ultra X inverters.

Energy: 6,144 Wh
Host: DELTA Pro Ultra / Ultra X inverter
Standalone: No — extra pack only
Chemistry: LFP
Warranty: 5 years (EcoFlow page)
Price snapshot: $2,299 add-on / $2,399 alone (us.ecoflow.com, 27 Sep 2026)

View Ultra extra on EcoFlow

EcoFlow DELTA 3 Max Plus smart extra battery

Max Plus extra battery second official angle

Max Plus extra battery third official angle

Manufacturer images · EcoFlow US 1 / 4

2,048 Wh add-on

DELTA 3 Max Plus extra

Pairs with Max Plus and Ultra Plus. Not a DELTA 3 extra and not an Ultra X extra.

Energy: 2,048 Wh
Host: DELTA 3 Max Plus / Ultra Plus
Weight: 16 kg ± 0.4 kg
Chemistry: LFP
Warranty: 5 years (3 + 2 with app registration)
Price snapshot: $859 sale / $1,329 list (EcoFlow US, 1 Oct 2026)

View Max Plus extra on EcoFlow

ECOFLOW

DELTA Pro 3 extra · $1,899 (19 Oct 2026)

Same-family pack as the 4 kW portable. Not an Ultra X extra.

View DP3 extra on EcoFlow

HOST

F3800 Plus if you do not own one yet

The extra pack does not work alone (Anker FAQ).

View F3800 Plus on Anker

Do not mix Anker, EcoFlow, and Bluetti packs. Cross-brand 48 V projects are not a recommendation.

2. Recharge after day one

EcoFlow 400 W folding portable solar panel, official packshot

EcoFlow 400 W panel standing on kickstand

EcoFlow 400 W panel unfolded, four sections

Manufacturer images · EcoFlow US 1 / 4

After-storm recharge

EcoFlow 400 W folding panel

IP68, XT60 in the box. $699 on EcoFlow US (25 Oct 2026). Not landfall power.

Rated power: 400 W
Conversion (mfr.): up to 23%
Weather: IP68
Cable: XT60 included
Kickstand: Adjustable self-supporting
Realistic day: Often 1–2 kWh in sun — fridge offset, not a house
Price snapshot: $699 (EcoFlow US, 25 Oct 2026)

View 400 W panel on EcoFlow Solar how-to

Anker 400 W kits

Often bundled with F3800 Plus on Anker’s site. Same-brand cable, fewer surprises. F3800 Plus solar input is up to 3,200 W.

View solar on Anker

3. Make the house circuits work (electrician)

Not DIY on a main panel

Inlet boxes and interlocks feed building wiring. Hire a licensed electrician. We link categories, not a single “best” SKU, because panel type varies.

EcoFlow home backup transfer switch kit, official packshot

Manufacturer images · EcoFlow US 1 / 1

6-circuit · $399

EcoFlow transfer kit

For DELTA Pro 3 and DELTA 3 Ultra Series. Indoor panels. Licensed electrician. Not SHP3.

Kit: 306A1 (EcoFlow US)
Circuits: 6
Pairs with: DELTA Pro 3 / DELTA 3 Ultra Series
Listing: cULus 1008
Install: Licensed electrician · indoor panels
Warranty: 5 years (page)
Price snapshot: $399 (EcoFlow US, 15 Sep 2026)

View transfer kit on EcoFlow House hookup notes

EcoFlow Smart Home Panel 3 closed official packshot

EcoFlow Smart Home Panel 3 second official angle

EcoFlow Smart Home Panel 3 with door open, 32-circuit interior

Manufacturer images · EcoFlow US 1 / 4

Ultra X automatic house

EcoFlow Smart Home Panel 3

32 circuits, 10-year page warranty, NEMA 3R. EcoFlow FAQ: does not support DELTA Pro 3.

Circuits: 32 independently controlled
Transfer: <20 ms with Ultra X
Grid: 120/240 V split-phase · 120/208 V
Enclosure: NEMA 3R (indoor/outdoor)
Weight: 88.8 lb (EcoFlow)
Compatible: Ultra X — not DELTA Pro 3
Warranty: 10 years (EcoFlow page)
Price snapshot: $3,299 · Ultra X + SHP3 $10,999 (27 Sep 2026)

View Smart Home Panel 3 SHP3 guide

30 A inlet box

Panel-specific. Match your enclosure, not a photo. Pair with a listed interlock or transfer switch — never a dryer outlet.

View inlets on Amazon

Generator interlock kit

Panel-specific. Cheaper than a full transfer switch on many 200 A panels. Still a permit job in most cities.

View interlock kits on Amazon

4. Soft-starts (the well / AC companion)

A $300–$400 soft-start can matter more than jumping from a 6 kW to a 12 kW battery. Micro-Air EasyStart is the name most homeowners are quoted. One Amazon listing for EasyStart Flex 398 was $399 when we looked; confirm the model matches your compressor. Well-pump soft-starts are a different SKU — match voltage and HP.

View soft-starts on Amazon

This page is extras for the systems above — not another list of competing power stations. If a unit cannot be checked against a current manufacturer spec sheet, it does not belong here.

BLUETTI extra capacity

Manufacturer images · BLUETTI US 1 / 2

Pairs only with EP900 / EP800-class

BLUETTI B500 expansion

Same-brand extra energy for the EP900 stack. Confirm live price — Bluetti listings move.

Nominal: 4,960 Wh
Usable: 4,464 Wh (90% DoD)
Chemistry: LFP
IP: IP65
Host: EP900 / EP800-class — does not run alone

View B500 on Bluetti