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BLUETTI B500K · Universal Expansion Battery · 5,120Wh
The B500K is a 5,120Wh LiFePO₄ expansion battery built for universal compatibility — Apex 300, AC300, AC500, AC200L, AC200MAX, and upcoming models all work with it, rather than being locked to one specific system. Rated for over 4,000 cycles (roughly a decade of use), it scales up to 100kWh combined, mounts to a wall or rack, and pairs with BLUETTI's SolarX 4K and Hub D1 accessories for a more connected setup.
BLUETTI's own "Universal Compatibility" positioning — one battery, multiple power station platforms.
Portable
Extends the Apex 300 platform's already-modular capacity further.
Commercial
Whole-home and small commercial backup platforms with real expansion headroom.
RV / Home
Popular mid-size power stations, plus BLUETTI's stated support for upcoming models too.
Substantial capacity added to whatever BLUETTI power station it's paired with.
Works with Apex 300, AC300, AC500, AC200L, AC200MAX, and BLUETTI's stated upcoming models.
Rated for over a decade of service, not just occasional emergency use.
A third-gen internal design built to be more resilient to real-world knocks and shocks.
Mount to save space, or pair with the separately-sold Foldable Trolley 2 for a mobile setup.
Keeps performance stable even under challenging operating conditions.
Combine multiple units for partial, whole-home, or small business backup.
Pairs with SolarX 4K and Hub D1 for a more integrated setup beyond just extra storage.
Most BLUETTI expansion batteries are built for a specific platform — B300K for Apex 300, B4810 for RV5-based 48V systems, B500 exclusively for EP800/EP900 home ESS. The B500K takes a different approach: BLUETTI markets it with "Universal Compatibility," working across Apex 300, AC300, AC500, AC200L, AC200MAX, and models still to come. That flexibility matters if a system might change platforms later, or if the same battery needs to serve more than one type of power station over time.
Physically, it's built to be moved or fixed in place depending on the setup — mount it to a wall or rack for a permanent install, or pair it with the separately-sold Foldable Trolley 2 for something more portable. A third-generation "wireless internal" design and dedicated cooling fan are meant to hold up to real-world knocks and challenging conditions better than earlier designs, and it connects into BLUETTI's broader ecosystem through accessories like SolarX 4K and Hub D1. Warranty coverage requires registering the product after purchase — BLUETTI's own FAQ confirms this step, though the base coverage length itself wasn't stated.
B500K Expansion Battery
| Total energy | 5,120 Wh |
| Chemistry | LiFePO₄ |
| Cycle life | 4,000+ cycles |
| Estimated lifespan | ~10 years |
| Internal design | 3rd-gen "wireless" frame |
| Cooling | Dedicated fan |
| Mounting | Wall/rack, or Foldable Trolley 2* |
| Compatible power stations | Apex 300, AC300, AC500, AC200L, AC200MAX, upcoming models |
| Ecosystem accessories | SolarX 4K, Hub D1 |
| Max combined capacity | 100kWh |
| Warranty | Registration required to claim** |
*Foldable Trolley 2 sold separately. **BLUETTI's own FAQ confirms a registration step is required to claim warranty, but doesn't state the base coverage length — the live page's Tech Specs tab was not accessible in a static fetch, so weight, dimensions, and exact charge/discharge current aren't included here rather than guessed.
Register the product on BLUETTI's website after receiving it — this is confirmed directly in BLUETTI's own FAQ as the required first step to claim warranty coverage.
Apex 300, AC300, AC500, AC200L, AC200MAX, and BLUETTI's stated upcoming models — marketed as "Universal BLUETTI Compatibility" rather than being locked to one platform.
Not confirmed in available sources — this varies by which power station it's paired with, and BLUETTI's own FAQ raises this exact question for AC300 and Apex 300 specifically without a visible published answer. Worth confirming the exact number for your specific setup directly with BLUETTI before purchase.
Not confirmed — BLUETTI's own FAQ asks this exact question (mixing B500K with B300K, B300, or B300S) without a visible published answer. Don't assume compatibility for mixed setups without checking directly.
Up to 100kWh combined, per BLUETTI's own stated maximum — enough for partial, whole-home, or small business backup depending on how many units are connected.
Yes — wall or rack mounting is standard, and it can also attach to BLUETTI's Foldable Trolley 2 (sold separately) for a more portable setup.
Free shipping on all orders within the mainland US (Hawaii, Alaska and overseas territories excluded - a freight forwarder is required). Orders ship directly from our brand partners' warehouses across the U.S. Order confirmation is emailed immediately; if an item is unexpectedly backordered we notify you before your card is charged. In-stock items are processed within 1-4 business days (cut-off 4:00 PM EST), transit is 3-6 business days, and tracking is emailed within 24 hours of shipment. Typical delivery is 4-10 business days from purchase. Minimum order value is $69.
You have 30 days from the delivery date to initiate a return (35 days for orders placed Nov 25-30 and Dec 25-31). Items must be unused, in original packaging with tags attached, and returns require prior authorization from our team.
To start a return: +1 (307) 317-7213, hello@ecosolarkits.com, or live chat. Read the full return and refund policy
