Wattstanding
FOSSiBOT FB3840 Expansion Battery - 3840Wh LFP (For FOSSiBOT F3600 Pro) (EUFB3840)

Product image: Fossibot

Expansion battery · Fossibot

FOSSiBOT FB3840 Expansion Battery - 3840Wh LFP (For FOSSiBOT F3600 Pro) (EUFB3840)

Fossibot · 3,840 Wh add-on

The short answer

The FOSSiBOT FB3840 Expansion Battery - 3840Wh LFP (For FOSSiBOT F3600 Pro) (EUFB3840) adds 3,840 Wh of storage. The listing says it is for FOSSiBOT F3600 Pro. Fossibot lists it at $1,499, about $390 per kWh.

Capacity
3,840 Wh
For
FOSSiBOT F3600 Pro
Weight
83.33 lb
Price seen
$1,499

Good fit if

  • You already own the compatible base unit and need longer runtime
  • You prefer adding storage to adding a second station

Look elsewhere if

  • You do not own the compatible base unit
  • You need more output watts — an expansion battery adds energy, not power
$1,499Fossibot listed price (base model) · seen 30 Sep 2026
View at Fossibot

Every link opens the product page for this exact model. We may earn a commission; it never changes what we publish. Disclosure

What it adds

An expansion battery adds watt-hours to a compatible power station without adding output: the base unit's inverter still limits how many watts you can run, but you can run them for longer.

Total capacity with this battery
Base unitBase capacityWith this batteryAC output (unchanged)
FOSSiBOT F3600 Pro Portable Power Station (USF3600-Pro)3,840 Wh7,680 Wh3,600 W
Wattstanding calculationWattstanding calculation — total capacity = base capacity + expansion capacity. Output watts stay at the base unit's rating.

Fit check before you buy

An expansion battery only works with the units its maker lists.

✓ Required? Check firsti Good to know
  • ✓Compatible base unitFOSSiBOT F3600 Pro
  • ?Connection cableSome expansion batteries need a specific cable or adapter that may be sold separately.
  • iWeight83.33 lb as stated.

Specifications

Each figure is labelled with where it comes from. Numbered references link to the source list below.

Manufacturer storeRetailer listingWattstanding calculationNot verified

Published specifications

Battery capacity3,840 Wh[S1]Manufacturer store
Listed for use withFOSSiBOT F3600 Pro[S1]Manufacturer store
Cycle life6,500 cycles[S1]Manufacturer store
Weight83.33 lb[S1]Manufacturer store
Warranty2+3 Years[S1]Manufacturer store

Wattstanding calculations

Price per kWh$390Wattstanding calculation

Limitations to weigh

  • Specifications are the maker's or seller's; Wattstanding has not tested this product.
  • Compatibility is the seller's statement; confirm it for your exact base unit and version.
  • Prices change; confirm the price and what is included.

Alternatives worth comparing

Jackery Battery Pack 3600 Plus3,584 Wh; $150 less
Anker SOLIX BP3800 Expansion Battery (A1790111-85)3,840 Wh; $301 more
EcoFlow DELTA Pro 3 Smart Extra Battery4,096 Wh; $315 more
Dabbsson DBS3000B Expandable Battery3,000 Wh; $100 less

Where to buy

Our link opens this exact product page. Prices and stock change; check before you order.

$1,499Fossibot listed price (base model) · seen 30 Sep 2026
View at Fossibot

Every link opens the product page for this exact model. We may earn a commission; it never changes what we publish. Disclosure

Questions buyers ask

Will the FOSSiBOT FB3840 Expansion Battery - 3840Wh LFP (For FOSSiBOT F3600 Pro) (EUFB3840) work with my power station?
The listing says it is for FOSSiBOT F3600 Pro. Confirm your exact model and version with the seller.
Where can I buy the FOSSiBOT FB3840 Expansion Battery - 3840Wh LFP (For FOSSiBOT F3600 Pro) (EUFB3840)?
1 seller list it: Fossibot.

Sources and verification

  1. Fossibot — FOSSiBOT FB3840 Expansion Battery - 3840Wh LFP (For FOSSiBOT F3600 Pro) — product page and specifications Retrieved 30 Sep 2026

Wattstanding has not tested this product hands-on. This reference is compiled from the sources above; our calculations are labelled and show their working. Electrical work belongs to a licensed electrician. Last verified 30 Sep 2026. How we work