The BLUETTI B300K2 Adds 2,764.8Wh of LiFePO4 Storage to Your Apex 300
The BLUETTI B300K2 Expansion Battery is the B300K configured for the Apex 300 power station. It adds 2,764.8Wh of LiFePO4 capacity with each pack and ships with the CA90 battery connection cable used to stack it with the Apex 300. B300K2 is BLUETTI's part number for this Apex 300 version of the B300K.
Start with one battery for longer backup and add more as your needs grow. A single Apex 300 supports up to six B300K batteries for 19,353.6Wh, and parallel Apex 300 systems scale much further. The B300K2 also has its own USB-A port, so it can charge a phone or run a small fan on its own.
BLUETTI B300K2 Features
2,764.8Wh Per Battery
Each pack stores 2,764.8Wh (51.2V, 54Ah), matching the Apex 300's built-in capacity. One B300K2 doubles an Apex 300 to 5,529.6Wh. BLUETTI estimates a 100W load would run about 22 hours on one battery.
Automotive-Grade LiFePO4 Cells
Square LiFePO4 cells, an AI battery management system and an aluminum casing provide long life and stable, safe operation. The battery reserves a small amount of energy to prevent over-discharge and protect its lifespan.
Stack and Mix With Other Batteries
The Apex 300 can mix B300K, B300 and B300S batteries up to six packs per unit. With a B300K connected, the Apex 300 and battery update their firmware together in one step.
Fast Charging Through the Power Station
The B300K2 charges through the connected power station at up to 60A. Paired with an Apex 300 on Turbo charging, the system recharges quickly from a wall outlet, generator or solar.
Standalone USB-A Power
A 12W USB-A port lets you charge a phone, tablet or small fan directly from the battery, even when it is not connected to a power station.
Monitored in the BLUETTI App
When connected to your power station, each battery's status appears in the BLUETTI app, so you can track charge levels and battery health.
Real-World Applications
Longer home backup. Extend how long your Apex 300 can run a refrigerator, furnace fan, lights and medical devices during an outage.
RV and off-grid living. Store more solar energy for nights and cloudy days.
Time-of-use savings. More stored energy lets you shift more of your home's usage away from peak-rate hours.
How It Compares to Common Alternatives
Versus the B500K. The B500K stores 5,120Wh in one 99.21 lb pack. The B300K2 stores 2,764.8Wh at 65.04 lbs, which is easier to lift and lets you add capacity in smaller steps.
Versus a second power station. An expansion battery adds capacity at a lower cost per watt-hour. Choose a second Apex 300 with a Hub A1 only if you also need more output power.
Is the B300K2 the Right Fit
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Power station. This version ships with the CA90 cable for the Apex 300. BLUETTI lists it as compatible with the AC200L, AC200MAX, AC300, AC500 and Apex 300; the AC500 needs BLUETTI's P090D to P150D cable, sold separately.
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Charging. The B300K2 cannot be charged directly from solar or a car outlet. It charges through the connected power station.
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UPS. It does not work as a standalone UPS or power bank.
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Environment. It is not waterproof. Charge between 32°F and 104°F.
This may be a good fit if
- You own an Apex 300 and want more runtime
- You want to add capacity in 2.7kWh steps
- You want long-life LiFePO4 storage
Common Questions
How Many Batteries Can I Connect to an Apex 300?
Up to six per Apex 300. With six B300K batteries, one Apex 300 reaches 19,353.6Wh.
Can I Use It in Freezing Weather?
It can discharge from -4°F to 104°F, but it should only be charged from 32°F to 104°F.
What If the Battery Runs Completely Empty?
Recharge it before it drops to 1%. If it has been fully discharged, place it somewhere at least 50°F for 12 hours before recharging.
What's Included
- 1 x BLUETTI B300K2 Expansion Battery
- 1 x Battery Connection Cable (CA90)
- 1 x User Manual
More Capacity for Your Apex 300
The BLUETTI B300K2 is a simple way to extend your Apex 300's runtime for home backup, RV trips and off-grid living. At Outbound Power, we can help you decide how many batteries your system needs. If you have questions, our team is happy to help.
BLUETTI B300K2 Battery Specifications
|
| Model |
BLUETTI B300K2 (B300K for Apex 300) |
| Battery |
| Capacity |
2,764.8Wh (51.2V, 54Ah) |
| Chemistry |
LiFePO4 (Lithium Iron Phosphate) |
| Cycle Life |
4,000+ cycles to 80% capacity |
| Output |
| USB-A Port |
12W Max., 5V/2.4A |
| General |
| Charging Current |
60A Max. (may decrease outside specified temperatures) |
| Discharging Current |
70A Max. |
| Expansion Ports |
2 x, 58.4V DC Max., 90A Max. |
| Weight |
65.04 lbs (29.5 kg) |
| Dimensions (L x W x H) |
20.67 x 12.87 x 8.23 in (52.5 x 32.7 x 20.9 cm) |
| Charging Temperature |
32°F to 104°F (0°C to 40°C) |
| Discharging Temperature |
-4°F to 104°F (-20°C to 40°C) |
| Storage Temperature |
-4°F to 104°F up to 1 month; -4°F to 77°F up to 6 months |
| Working Humidity |
5% to 95% RH |
| Compatibility |
AC200L, AC200MAX, AC300, AC500, Apex 300 |
| Warranty |
3 + 1 Years (extra year with registration) |
BLUETTI B300K2 Battery Manual