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BigBattery

BigBattery NEXUS + EG4 12000XP V2 Off-Grid Kit | 30–45 kWh | 48V LiFePO4

SKU K0155

Regular price: $8,085.00

Regular price: $8,085.00

✅ 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

Double the inverter output: BigBattery NEXUS 48V 15 kWh LiFePO4 batteries matched with the EG4 12000XP V2 all-in-one off-grid inverter. This is the configuration for full-size off-grid homes running well pumps, mini-splits, and shop tools simultaneously — with 30 or 45 kWh of storage to carry the load overnight and through cloudy stretches.

What's in this kit

1 × EG4 12000XP V2 off-grid inverter — 12,000W continuous split-phase 120/240V output, integrated MPPT solar charge controllers, and built-in AC charging in one wall-mounted enclosure
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)
Closed-loop communication — battery settings and communications configured to work with the 12000XP V2 for accurate state-of-charge reporting and coordinated charging

Is this the right size for you?

It fits if: you're running a full-size home off-grid — central or multi-zone air conditioning, a well pump, electric range or dryer, and everyday loads at the same time — and you cycle the bank daily. 12,000W of output means you rarely think about what's on; 30–45 kWh means the bank keeps up with real household consumption.

Size down the inverter if: your loads are cabin-scale — the NEXUS + EG4 6000XP kit costs less and keeps the same battery platform.

Start smaller: the single-battery 15 kWh version of this kit is listed separately, and NEXUS units combine — 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	EG4 12000XP V2 all-in-one
Continuous output	12,000W, split-phase 120/240V
Solar charging	Integrated MPPT charge controllers (solar array sold separately)
System voltage	48V
Communication	Closed-loop battery-to-inverter
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 EG4 12000XP V2 carries a 5-year full parts-or-product replacement manufacturer warranty; EG4 requires warranty registration within the first year of purchase (or proof of purchase from an authorized distributor) to keep coverage valid.

Common questions

Do I need an electrician?

Placing the batteries and mounting the inverter are owner-level tasks, but the AC side — wiring 12,000W of split-phase output into a main panel, grounding, bonding, and code compliance — is work for a licensed electrician and typically requires a permit and inspection.

Are solar panels included?

No. Panels, racking, and array wiring are sized to your site and the inverter's MPPT input range, and are 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.