Expansion battery entity · 2.76 kWh LiFePO4 expansion · Current
BLUETTI B300K Expansion Battery
2,764.8 Wh LiFePO4 expansion battery for BLUETTI's AC-series stations (AC200L, AC200MAX, AC300, AC500), 29.5 kg. Adds capacity to the host and carries a single 12 W USB-A as its only outlet, with no direct AC, solar or car charging of its own. How many chain depends on the host, from 2 up to 6.
brand: BLUETTIcapacity: 2764.8 Whconfidence: highupdated: Aug 15, 2026
This battery only works with the hosts named below. An expansion battery only enlarges a specific host power station. It is not a general-purpose battery and, on its own, usually has no inverter and no outlets at all. Compatibility below is recorded verbatim from the manufacturer and is never inferred from a matching connector, a shared brand or a similar capacity: pairing one with a host it was not built for can damage equipment. Capacity shown is this unit's own, never a combined station-plus-expansion system total.
Manufacturer product image, from BLUETTI.
Shown for identification only; specifications come from the sources listed below.
The BLUETTI B300K is a 2,764.8 Wh LiFePO4 expansion battery (54 Ah at 51.2 V nominal) in a 29.5 kg case, built to enlarge BLUETTI's AC-series power stations. BLUETTI states it integrates with the AC200L, AC200MAX, AC300 and AC500. It has almost no output of its own: a single USB-A port rated 12 W (5 V / 2.4 A), and BLUETTI's own FAQ answers 'No' to solar and car charging on the unit, so it can only be recharged through its host. The number of expansion units per host varies by model: 2 on the AC200L, 2 on the AC200MAX, 4 on the AC300 and 6 on the AC500. Warranty is 3 years base, extended to 4. A serious variant hazard applies here: a separate 'B300K for Apex300' SKU (prefix B300K2-) shares the name, and the bundle product page bleeds that variant's Apex 300 compatibility, a 6,000-cycle figure and a bundled charger accessory's specs into the base record. This record is anchored only on the canonical B300K page and its manual, which describe the AC-series unit rated for 4,000-plus cycles. No cycle count is published here as a DoD-qualified rating because the manufacturer states capacity retention (80%) rather than a depth-of-discharge basis.
Variant note: Canonical B300K expansion battery for the AC-series (AC200L/AC200MAX/AC300/AC500). NOT the 'B300K for Apex300' SKU (prefix B300K2-), which is a different, non-interchangeable product despite the shared name.
Data note: Values anchored ONLY on the canonical BLUETTI B300K expansion-battery page and its manual PDF (2026-08-15). SERIOUS VARIANT HAZARD preserved: a separate 'B300K for Apex300' SKU (prefix B300K2-) shares the B300K name. The /products/b300k bundle page bleeds that variant's Apex 300 compatibility and a 6,000-cycle figure into the base record, and bleeds a bundled Charger 2 accessory's solar input, IP20 rating, 1.59 kg weight and small dimensions into the spec table. None of those belong to this unit: the AC-series B300K is 29.5 kg, 4,000-plus cycles, AC200L/AC200MAX/AC300/AC500 only, no direct charging. maxChainable is null because it varies by host: AC200L 2, AC200MAX 2, AC300 4, AC500 6 (recorded here rather than as a single number that would misrepresent the others). cycleLifeCycles is null by policy: the 4,000-plus figure is quoted to 80% capacity retention, not a depth-of-discharge basis. hasOwnOutlets is true, justified by the single 12 W USB-A port. Storage temperature is not stored as a single range because BLUETTI publishes duration-dependent windows (-20 to 40 C for up to 1 month, -20 to 25 C for up to 6 months); collapsing them to one range would hide the duration dependence. Hero image is a clean BLUETTI 3D render (provenance noted).
Specifications
Host compatibility leads this table because it is what makes an expansion battery meaningful,
and it is recorded verbatim from the manufacturer and never inferred. The capacity shown is this
unit's own rated energy, not a combined host-plus-expansion system total. Any cycle-life figure
carries the depth of discharge it is quoted at, and figures the manufacturer does not publish are
left blank rather than estimated. Exact claims and links are in the
provenance table.
Host compatibility
Attribute
Value
Official compatibility statement
Effortlessly integrates with BLUETTI AC200L, AC200MAX, AC300, and AC500 power stations
Host models named by the manufacturer
AC200L, AC200MAX, AC300, AC500
Expansion units the host supports
Not stated
Capacity (this unit only)
Attribute
Value
Rated energy
2,764.8 Wh
Rated capacity
54 Ah
Nominal voltage
51.2 V
Chemistry
LiFePO4 (lithium iron phosphate)
Integration
Attribute
Value
Outlets on the expansion unit itself
One USB-A, 12 W max (5 V / 2.4 A). This is the unit's only output port; it has no AC outlets.
Direct charging inputs
None direct: the B300K charges only through its host station. BLUETTI's FAQ explicitly answers 'No' to solar and car charging on the unit itself.
Cycle life
Attribute
Value
Rated cycle life
No cycle-life figure published
Cycle-life test conditions
BLUETTI rates the canonical AC-series B300K at 4,000-plus cycles to 80% of original capacity. That is a capacity-retention figure, not a depth-of-discharge basis, so no DoD-qualified cycle count is stored. A 6,000-cycle figure appears only on the bundle page and belongs to the separate B300K-for-Apex300 variant (see notes).
Temperature
Attribute
Value
Charge temperature range
0 °C to 40 °C (32 °F to 104 °F)
Discharge temperature range
-20 °C to 40 °C (-4 °F to 104 °F)
Physical
Attribute
Value
Weight
29.5 kg (65.0 lb)
Dimensions (L × W × H)
525 × 327 × 209 mm
Model & availability
Attribute
Value
Warranty
3 years
Release status
Current
Market region
US
Use cases
Enlarging a BLUETTI AC200L, AC200MAX, AC300 or AC500 for longer outage or off-grid runtime
AC500 or AC300 systems that need several stacked batteries for whole-day or multi-day backup
Strengths and weaknesses
Strengths
Large 2,764.8 Wh LiFePO4 capacity in a single stackable unit
Broadest host coverage here: four named AC-series stations
Chemistry, capacity, weight and dimensions all published, with a manual PDF as a source
A small 12 W USB-A trickle port for phones even when detached from a host
Weaknesses
No AC output and no direct solar, car or AC charging: it must be recharged through a host
How many units chain depends entirely on the host station (2 to 6)
Name collides with a separate 'B300K for Apex300' SKU whose specs bleed onto the shared bundle page
29.5 kg: a heavy single-unit lift
Where to buy
Retail offers — a commerce layer, not a source for any specification on this page.
No current price is tracked for this product; check the merchant for pricing.
Core specifications come from official manufacturer sources only, with the exact claim text
preserved per field. Spec sheets and manuals outrank marketing copy. See the
methodology for the full policy.
Official manual (PDF) — 54 Ah x 51.2 V = 2764.8 Wh, exactly matching the stated capacity.
high
weightKg
29.5
—
Official manual (PDF) — Published weight 29.5 kg; sourced via research handoff (2026-08-15). This is the AC-series unit, not the 1.59 kg accessory whose weight bleeds onto the bundle page.
high
dimensionsMm
[525,327,209]
—
Official manual (PDF) — 525 x 327 x 209 mm; sourced via research handoff (2026-08-15).
high
officialCompatibilityStatement
Effortlessly integrates with BLUETTI AC200L, AC200MAX, AC300, and AC500 power stations
Effortlessly integrates with BLUETTI AC200L, AC200MAX, AC300, and AC500 power stations
Official product page — Four named AC-series hosts. Anchored on the canonical page, not the bundle page that adds Apex 300.
high
compatibleHostModels
["AC200L","AC200MAX","AC300","AC500"]
AC200L, AC200MAX, AC300, and AC500
Official product page — Chain limits per host: AC200L 2, AC200MAX 2, AC300 4, AC500 6.
