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BLUETTI B300K Expansion Battery, 2764.8Wh LiFePO4 Pack for Power Station AC200L AC300 AC500 AC200MAX, Extra Battery for Home, Emergency, Road Trip

  • Based on 233 reviews
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Availability: In Stock.
Fulfilled by Bluetti

Arrives Tuesday, Mar 31
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Style: ‎BLUETTI B300K for AC300


Features

  • [Backward and Forward Compatibility] - Seamlessly works with past and future BLUETTI power stations featuring an expansion port, including AC200L, AC200MAX, AC300, AC500, and AC200PL. Ready for what's next.
  • [Next-Generation Cells] - Equipped with advanced cells that provide at least 4,000 cycles to 80% capacity, offering a 15% boost in lifespan. Plus, they perform even better at high temperatures.
  • [Next-Gen Design Architecture 2.0] - The B300K expansion battery pack's wireless internal design minimizes failure risk and maximizes space efficiency, resulting in a more compact, portable product.
  • [Built-In USB Charging Port] - It's like having a massive power bank with a USB port, ready for those "just-in-case" moments. Connect it to any compatible BLUETTI power station for added versatility.
  • [What You Get] - BLUETTI B300K expansion battery, P090A battery expansion cable for power station AC200L AC300 AC200MAX and user manual.

Connector Type: usb-a,usb-c


Brand: BLUETTI


Color: Black


Special Feature: electricitygenerator


Voltage: 120 Volts


Manufacturer: ‎BLUETTI


Part Number: ‎4694987031


Item Weight: ‎65 pounds


Product Dimensions: ‎20.47 x 12.6 x 10.31 inches


Item model number: ‎B300K


Batteries: ‎1 Lithium Ion batteries required. (included)


Size: ‎3072Wh


Color: ‎Black


Style: ‎‎BLUETTI B300K for AC300


Material: ‎Metal


Power Source: ‎Solar Powered


Voltage: ‎120 Volts


Wattage: ‎2764.8 Watt-hours


Horsepower: ‎0.13


Maximum Power: ‎100 Watts


Item Package Quantity: ‎1


Special Features: ‎electricitygenerator


Included Components: ‎B300K battery, P090A battery expansion cable


Batteries Included?: ‎Yes


Batteries Required?: ‎No


Battery Cell Type: ‎Lithium


Warranty Description: ‎4-year Warranty


Date First Available: February 20, 2022


Frequently asked questions

If you place your order now, the estimated arrival date for this product is: Tuesday, Mar 31

This item is non-returnable:

Non-returnable. Transportation of this item is subject to hazardous materials regulation

View our full returns policy here.

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Leasing options through Acima may also be available during checkout.

Learn more about financing & leasing here.

Top Amazon Reviews


  • Great value, reliability, and lifespan
Style: ‎BLUETTI B500K for AC300/AC200L
My Review of the BLUETTI B500K Expansion Battery. The BLUETTI B500K is a solidly built, no-frills 5,120Wh (5.12 kWh) LiFePO4 expansion battery—well-made and reliable. I’ve found BLUETTI consistently outperforms more hyped brands in the portable power space. I’ve owned an AC300 for nearly 5 years, and their customer support has been exceptional—friendly, knowledgeable (the reps often seem like engineers), and quick to resolve issues. BLUETTI’s edge comes from using LiFePO4 cells: over 4,000 cycles to 80% capacity means 10+ years of daily use, with better safety (no thermal runaway risk) than standard lithium-ion alternatives. At (promo price, it delivers excellent value at about $380 per kWh with the promo pricing that comes up often, it’s competitive-with EcoFlow or Anker options, especially factoring in longer life and broad compatibility (AC300, AC200L/MAX, AC500, Apex 300). Stack up to six per unit for massive scaling (up to 100 kWh systems). The hardware stays straightforward, but the BLUETTI app adds real utility: real-time SOC, power input/output, historical charts for solar generation vs. usage, and trends over time. This helps optimize—avoid wasting excess solar when batteries fill, adjust loads to maintain healthy charge levels, or prep better for outages by tracking patterns. It connects via Bluetooth or WiFi/cloud and has improved significantly. Not the lightest (~99 lbs) for moving, but perfect for stationary home backup or off-grid setups tied to my AC300—it doubles capacity seamlessly and powers essentials for days. If you’re in the BLUETTI ecosystem or building expandable storage, the B500K is a smart, cost-effective upgrade. BLUETTI keeps delivering where it matters ... show more
Reviewed in the United States on January 27, 2026 by David

  • Excellent
Style: ‎BLUETTI B300K for AC300
An xtra battery , plug and play right out of the box, plugs in to your portable power station to get xtra power, needed to get you through the night until the Sun comes out again, at $0.43 per Wh is an unbeatable price, almost 2800 Wh , cable is 32 inches long total, each connector is 4 inches and cable is 26 inches long, also update the firmware right away, very portable ... show more
Reviewed in the United States on January 26, 2026 by JD

  • Worth the Money
Style: ‎BLUETTI B300K for AC300/AC200L
I have 6 different Bluetti products and I have not had any problems. They may not be the cheapest but so for they have been the best quality and that makes all the difference. Most times you get what you pay for. I'd rather pay just a little more and not have any problems than try to cheap out on inferior products that have issues. ... show more
Reviewed in the United States on February 26, 2026 by KYLE BANTZ

  • Stop thinking about it and buy!
Style: ‎BLUETTI B300K for AC300
I recently completed a solar setup with 6 ZOUPW 450W panels, the Bluetti AC500, and 3 B300K batteries, and I honestly couldn't be happier. The system has been performing phenomenally — I’m generating over 2.5kW of clean, reliable solar power, which keeps my essential loads running and charges the battery bank with no problem, even on partially cloudy days. The AC500 is the brains and brawn of the operation — it manages solar input effortlessly and distributes power to the batteries and devices with incredible efficiency. With over 9kWh of battery storage thanks to the 3 B300Ks, I’m confident we can run for extended periods completely off-grid if needed. The app interface, monitoring, and expandability make it feel like something straight out of a sci-fi movie. I haven’t even installed the Bluetti sub panel yet, which will allow me to supplement power directly to the house. Once that’s in place, I’ll be able to run high-demand appliances without even noticing we’re on solar. This system has turned my home into a quiet, self-reliant energy hub — no noisy gas generators, no fuel to store, and virtually no maintenance. If you're considering building a home backup or hybrid solar system, this combo is absolutely worth it. It’s powerful, scalable, and ready for any power outage or energy-conscious lifestyle. 10/10 would recommend! ... show more
Reviewed in the United States on June 22, 2025 by Danielle Corsan Danielle Corsan

  • Lots of power!
Style: ‎BLUETTI B300K for AC300
Works great! It is NOT portable unless your hobby is lifting weights. Its heavy! Slap it in a corner, plug it in, use it, and forget about it.
Reviewed in the United States on January 18, 2026 by Bryan

  • Excellent expansion of solar power.
Style: ‎BLUETTI B300K for AC300
The media could not be loaded. Recently bought this Bluetti B300K to exoand my AC200Max. It over doubles the power of the AC200Max. It comes with the cable to connect it. Easy to hook up. The quality of build and materials is great! It charges only through beung plugged into your Bluetti solar generator that you plan to expand the battery power of. Once hooked up, you can charge them with solar panels, plug into an outlet. The B300K comes with only one USB-A type USB input. The power button must be held down for about 3 seconds to turn on. The lights are bright. It has 4 lights to represent the batter power of it. Each representing 20% of the power. And the power button lights up. This battery has a lifecycle of up to 3,500 charges from 0 to 100. After that, the battery will deplete 20%. Meaning you CAN STILL USE IT afte the 3,500 charges. And charge it from 0 to 80% of the battery's power for a long time. The functionality is easy and nice! The B300K weighs around 65lbs. But is easy to move around. The handles are sturdy. You can also see the battery percentage with the Bluetti app. And control several different Bluetti generator models with it. ... show more
Reviewed in the United States on December 31, 2024 by Rezivor Rezivor

  • It is a great battery but does not have a connector port on the left side
Style: ‎BLUETTI B300K for AC300
I bought 2 B300 batteries for my AC200MAX and while the batteries are nice, I can't see them since they face the wall. The B300 battery was made for the AC300 and AC500 which have battery connectors on the right side. The connectors on the AC200MAX are on the left side, and the battery cables are too short to go from the left to the right connectors. So, my batteries have to face the wall. Bluetti, in its lack of thought - does not have a 3-foot "extension cord" to fix the situation (not that I asked but searched the web site). This review only gets 4 stars since the power button is also in (front) back of the B300 so is hard to turn on and I have to press the button (on both) to turn it on. My components are stacked to take up minimal space. The B300 has 4 battery connectors on the right and none on the left. The only way Bluetti gets 5 stars is if they send me the 3-foot extension to make one cord longer or send the full 6-foot battery cable. ... show more
Reviewed in the United States on January 29, 2023 by Michael See

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