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BigBattery

BigBattery NEXUS + APEX 6.5K Off-Grid Kit | 30–45 kWh | 48V LiFePO4

SKU K0192

Regular price: $7,680.00

Regular price: $7,680.00

✅ Order by 12:00 PM EST and processing starts the same day (ships within 1–2 business days). Free, insured US shipping — delivery in 4–7 business days. Oversized items ship via LTL freight and we coordinate delivery with you by phone.

Product variants

Quantity

OffGrid Horizon Family Owned and Operated

🏔️ OffGrid Horizon is family-owned & off-grid obsessed. Read our story →

Shipping: how fast & how it works

Free standard shipping on every US order — no shipping charges at checkout, no hidden fees, and every shipment is insured against loss or damage.

Processing: 1–2 business days. Order before 12:00 PM EST and processing begins the same day.
Delivery: 4–7 business days via USPS, UPS or FedEx. Tracking is emailed the moment your order ships.
Large items (solar kits, batteries, shelters): delivered by LTL freight carriers such as FedEx Freight, Old Dominion or XPO. The carrier calls ahead to schedule a delivery window — please inspect the pallet and note any damage on the delivery receipt before signing, and we’ll take care of the rest.

Questions about delivery to your location? Call (302) 496-3554 (Mon–Fri, 9am–4pm EST) — we’re happy to check before you order.

What is your Return Policy?

At OffGrid Horizon, we want every customer to shop with confidence. If something doesn’t go as planned, we’ve made returns and refunds simple and fair. Here’s how it works:

1. Return Window

You can request a return within 30 days of receiving your order. Unfortunately, we’re unable to accept returns after that time frame.

2. Who Pays for Return Shipping?

If your item arrives damaged, defective, or incorrect, we’ll cover the return shipping cost — and you’ll receive a full 100% refund or replacement, including any original shipping costs.
If you’re returning an item because you changed your mind, you’ll be responsible for return shipping, and a 25% restocking fee applies.

3. Damaged or Defective Items

Received something broken or not working properly? Contact us within 30 days. We’ll provide a prepaid return label and once the item is returned and inspected, we’ll issue either a full refund or a replacement.

4. Changed Your Mind?

If you no longer want the item, you can return it within 30 days — as long as it’s unused, unopened, in its original packaging, and in resellable condition.

5. Refund Processing

Once we receive and approve your return, we’ll send a confirmation email and issue a refund to your original payment method within 7 business days. Please allow additional time for banks or credit card companies to process and reflect the refund.

How to start a return: email sales@offgridhorizon.com or call (302) 496-3554 (Mon–Fri, 9am–4pm EST) with your order number — we’ll send return instructions and your RMA right away.

Product Description

A high-capacity off-grid power package built around the BigBattery NEXUS 48V 15 kWh LiFePO4 battery and the APEX 6.5K all-in-one off-grid inverter. With 30 or 45 kWh of storage on tap, this system is sized for off-grid homes, cabins, and workshops that need dependable power through the night and across cloudy stretches — not just through a short outage.

What's in this kit

1 × APEX 6.5K off-grid inverter — an all-in-one unit for 48V systems: 6,500W of continuous split-phase 120/240V output, integrated MPPT solar charge controller, and battery charger in a single wall-mounted chassis
Your choice of 2 or 3 × BigBattery NEXUS 48V 15 kWh LiFePO4 batteries — 30 or 45 kWh of high-capacity storage, each in a floor-standing cabinet with a built-in battery management system (BMS)
Matched pairing — inverter and batteries are configured to work together out of the box

Is this the right size for you?

It fits if: your daily loads are cabin- or homestead-scale — refrigeration, lighting, pumps, electronics, and moderate 240V appliances — but you draw on the bank every day and want multi-day autonomy. The 6,500W inverter covers the loads; 30–45 kWh covers the nights and the weather.

Choose the APEX 10K version if: peak power is your constraint — starting large motors, running several 240V appliances at once, or powering a full-size home.

Start smaller: the single-battery 15 kWh version of this kit is listed separately, and NEXUS units combine — so you can begin there and add batteries as your needs grow.

Specifications

Battery	2 or 3 × BigBattery NEXUS, 48V LiFePO4, 15 kWh each
Total storage	30 or 45 kWh
Battery chemistry	LiFePO4 (lithium iron phosphate) with built-in BMS
Inverter	APEX 6.5K all-in-one: 6,500W continuous split-phase 120/240V
Solar charging	Integrated MPPT charge controller (solar array sold separately)
System voltage	48V
Expandable	Yes — additional NEXUS batteries can be combined

Warranty & support

Batteries: NEXUS batteries are covered by BigBattery's 12-year manufacturer warranty, backed by lifetime USA-based technical support. Inverter: the APEX 6.5K carries a 5-year limited manufacturer warranty.

Common questions

Do I need an electrician?

Placing the batteries and mounting the inverter are owner-level tasks, but the AC side — panel interconnection, grounding, bonding, and code compliance — is work for a licensed electrician and typically requires a permit and inspection.

Are solar panels included?

No. The MPPT input is ready for an array, but panels, racking, and array wiring are sized to your site and sold separately. Select your capacity from the Battery Configuration menu — pricing is for the complete kit.

How does LiFePO4 handle cold weather?

LiFePO4 batteries discharge reliably in freezing temperatures, but charging below freezing is restricted by the BMS to protect the cells. Install the batteries in an insulated or conditioned space to keep charging available year-round.