BLUETTI B500K Expansion Battery, 5,120Wh LiFePO4 for Apex 300

Some backup setups need more stored energy in the power system already in place, rather than another standalone unit. The BLUETTI B500K is an expansion battery for adding capacity to compatible BLUETTI power stations, with 5,120Wh in each pack and LiFePO4 battery chemistry.

This version includes the CA90 connection cable for the Apex 300. Add one pack to extend the energy available for home backup, emergency readiness, or off-grid use, then scale the setup with additional B500K batteries as your needs grow.

Everyday use

For a home backup setup, the B500K adds stored capacity to an Apex 300 system for supporting connected devices during an outage. At a campsite, in an RV, or at an off-grid location, it serves the same role: expanding the energy reserve in a compatible power station rather than operating as a standalone power station. The battery’s 5,120Wh capacity gives you a clear basis for planning which devices and activities the larger system will support.

Charging follows the input options of its host power station, including AC, solar, vehicle, or generator charging. Compatible accessories can also charge the B500K independently, including BLUETTI SolarX 4K and the Alternator Charger. The CA90 cable included with this version is compatible with the Apex 300, making this configuration suited to expanding that system.

Benefits

Capacity can grow with the setup. Up to six B500K batteries can be connected to an Apex 300, and the product information describes a system of three Apex 300 units and 18 B500K packs scaling to 100kWh. That makes the battery useful for planning a larger backup or off-grid energy reserve in stages, instead of choosing a single fixed-capacity configuration.

LiFePO4 chemistry is rated for 4,000+ cycles to 80% capacity. BLUETTI’s Architecture 2.0 design uses a cable-free internal layout, described as reducing failure risks and saving space. What does that mean for a growing setup? It gives capacity expansion a defined role within the BLUETTI ecosystem, with compatible accessories such as SolarX 4K, the Alternator Charger, and Hub D1 also listed for integration.

Quick overview

• Type: Expansion battery for compatible BLUETTI power stations
• Capacity: 5,120Wh per pack
• Battery type: LiFePO4, rated for 4,000+ cycles to 80% capacity
• Compatibility: Apex 300, AC200L, AC200MAX, AC300, and AC500
• Included cable: CA90, compatible with Apex 300
• Dimensions: 20.5 x 12.9 x 12.2 in
• Weight: 99.2 lbs

Is it worth it?

The B500K makes sense when the goal is to add substantial stored energy to a compatible BLUETTI power station, especially an Apex 300 setup using the included CA90 cable. Its 5,120Wh capacity per pack, expandable configuration, and stated cycle rating give buyers practical details for matching a battery expansion to backup, RV, camping, or off-grid plans.

For a system that needs to scale beyond one battery, the option to connect multiple B500K packs is the central advantage. Choose it to build out a compatible BLUETTI setup around a larger energy reserve, with charging through the host station or compatible accessories.