BLUETTI B300K Expansion Battery | 2764.8Wh
Overview
The BLUETTI B300K is a 2764.8Wh LiFePO4 expansion battery that adds capacity to a compatible BLUETTI power station. It suits home backup, off-grid setups, motorhomes, and extended NZ outages. The B300K is the current-generation replacement for the discontinued B300, and it can still be stacked alongside existing B300 and B300S batteries, so an older system can grow without starting again.
The B300K pairs with the BLUETTI Apex 300, AC300, AC500, AC200MAX and AC200L. The Apex 300 alone accepts up to six batteries, taking total system capacity to 19353.6Wh. The included P090A cable fits the AC300, AC200MAX and AC200L. The Apex 300 and the AC500 each connect with a different cable, sold separately (details in the compatibility section below). The B300K recharges through its host station, reaching 80% in around 45 minutes on an AC300 or AC500. It is not a standalone power station and has no AC output of its own. The built-in USB-A port charges phones and small devices directly. Please confirm compatibility with us before purchasing.
BLUETTI B300K Specs:
- Capacity: 2764.8Wh (51.2V, 54Ah)
- Battery Type: LiFePO4 (Lithium Iron Phosphate)
- Life Cycles: 4000+ cycles to 80% original capacity
- Expansion Ports: 2 x Expansion Port, 58.4VDC Max., 90A Max.
- USB-A Port: 12W Max., 5V / 2.4A
- Charging Current: 60A Max.
- Discharging Current: 70A Max.
- Weight: 29.5kg
- Dimensions (L x W x D): 525 x 327 x 209mm
- Charging Temperature: 0°C to 40°C
- Discharging Temperature: -20°C to 40°C
- Storage Temperature: up to 1 month: -20°C to 40°C; up to 6 months: -20°C to 25°C
- Working Humidity: 5% to 95%RH
What's in the Box?
- 1 x BLUETTI B300K Expansion Battery
- 1 x Battery Expansion Cable (P090A)
- 1 x User Manual
- Download the BLUETTI B300K user manual (PDF)
- Warranty: 4-year warranty
Note: The B300K is an expansion battery, not a standalone power station. A compatible BLUETTI power station (sold separately) is required for AC output and for recharging the battery.
Power Expansion for Every Situation
The B300K adapts to your setup, whether you are backing up the house through an outage or powering an off-grid weekend. Stack multiple B300K batteries on one host, or mix and match with existing B300 and B300S batteries, and scale the system to the capacity you actually need rather than replacing what you already own.
Compatible Across the BLUETTI Range
The B300K integrates with the AC300 (up to 4 batteries for 11059.2Wh of added capacity), the AC500 (up to 6 batteries, 16588.8Wh added), and the AC200MAX and AC200L (up to 2 batteries each, 5529.6Wh added). It also pairs with the current BLUETTI Apex 300, which accepts up to six B300K for 19353.6Wh of total system capacity (including the Apex 300's own 2764.8Wh battery).
The included P090A cable fits the AC300, AC200MAX and AC200L. The Apex 300 requires a P090D cable and the AC500 a P090D to P150D cable; both are sold separately.
LiFePO4 Cells Built to Last
The B300K uses square LiFePO4 cells rated for 4000+ charge cycles to 80% of original capacity, managed by BLUETTI's AI-BMS battery management system. An aluminium casing and an efficient cooling fan protect the pack, so the battery keeps working through years of regular charging and discharging.
80% Charged in 45 Minutes
Paired with an AC300 or AC500, the B300K recharges to 80% in around 45 minutes, so a short window of mains power or generator time puts most of the capacity back before the next outage or the next leg of the trip.
Charge rate is managed by the host power station and slows outside the 0°C to 40°C charging temperature range.
USB-A Port for Direct Charging
A built-in 12W USB-A port lets the B300K top up phones, tablets, and small devices on its own, handy in a tent or during an outage when the host station is busy elsewhere. For anything bigger, the B300K feeds its capacity through a connected BLUETTI power station.
Pairs Well With
The B300K is built to expand a BLUETTI power station system. For a current-generation setup it pairs with the BLUETTI Apex 300, which accepts up to six B300K batteries for whole-home backup, and it also expands the AC300, AC500, AC200MAX and AC200L. If you want more capacity from each battery, the BLUETTI B500K Expansion Battery is an alternative for the same hosts, adding 5120Wh per unit rather than 2764.8Wh. If you are unsure which host or cable your setup needs, please confirm compatibility with us before purchasing.
Frequently Asked Questions
Does the B300K work with the BLUETTI Apex 300?
Yes. The Apex 300 accepts up to six B300K expansion batteries, taking the total system capacity to 19353.6Wh, enough for extended whole-home backup or serious off-grid use. Note that the Apex 300 connects with a P090D cable, which is sold separately.
Which other BLUETTI power stations is the B300K compatible with?
The B300K works with the AC300 (up to 4 batteries), AC500 (up to 6 batteries), AC200MAX (up to 2), and AC200L (up to 2). The included P090A cable covers the AC300, AC200MAX and AC200L. Connecting to the AC500 requires a P090D to P150D cable, which is sold separately. If you are unsure about your model, contact us before ordering.
Can the B300K power appliances on its own?
No. The B300K has no AC output of its own, so it cannot run appliances as a standalone unit. It does have a 12W USB-A port for charging phones and small devices directly; everything else runs through the connected host power station.
Can I mix the B300K with my older B300 or B300S batteries?
Yes. The B300K can be stacked alongside existing B300 and B300S batteries on a compatible host, so you can add capacity to an older system without replacing the batteries you already own. One exception: on the Apex 300, BLUETTI recommends against mixing battery models, so keep an Apex setup to B300K units only.
Is the B300K a replacement for the B300?
Yes. The B300K is the current-generation successor to the discontinued B300, with the same 2764.8Wh LiFePO4 capacity class. Existing B300 owners can keep using their batteries and add B300K units alongside them.
How fast does the B300K recharge?
Connected to an AC300 or AC500, the B300K recharges to 80% in around 45 minutes. Charging is managed by the host power station, and the rate reduces outside the 0°C to 40°C charging temperature range.
How long will the battery last?
The LiFePO4 cells are rated for 4000+ charge cycles before capacity drops to 80% of new. At one full cycle per day, that works out to more than a decade of use. The pack itself is backed by a 4-year warranty.