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BigBattery

BigBattery NEXUS 48V LiFePO4 Battery | 15 kWh

SKU F-NXUS-48150-G1

Regular price: $3,375.00

Regular price: $3,375.00

✅ 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.

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

The BigBattery NEXUS is a 48V, 15 kWh LiFePO4 battery designed as high-capacity storage for off-grid and home backup systems. A single NEXUS provides substantial storage from one floor-standing cabinet, and multiple units combine to scale total capacity — it's the battery at the core of BigBattery's NEXUS off-grid kits with the EG4 6000XP, EG4 12000XP, and APEX inverters.

Why the NEXUS

15 kWh from a single unit — one cabinet instead of a wall of small batteries, with fewer connections to make and maintain
LiFePO4 chemistry — stable lithium iron phosphate cells with a built-in battery management system (BMS) that monitors and protects the pack
Expandable: combine multiple NEXUS units to reach 30, 45 kWh and beyond as your needs grow
Broad inverter compatibility: works with 48V off-grid and hybrid inverters, with communications for closed-loop charging on compatible models

Who it's for

Off-grid homes, cabins, and backup installations that want serious storage with minimal complexity. If you'd rather scale in smaller 5.12 kWh steps or need UL9540A paperwork for permitting, compare the stackable ETHOS platform. For a complete system, see the NEXUS kits with EG4 6000XP, EG4 12000XP V2, or APEX inverters.

Specifications

Nominal voltage	48V
Capacity	15 kWh per unit
Chemistry	LiFePO4 (lithium iron phosphate)
Protection	Built-in BMS with cell monitoring
Expandability	Multiple units combine for greater capacity
Compatibility	48V off-grid and hybrid inverters
Form factor	Floor-standing cabinet
SKU	F-NXUS-48150-G1

Warranty & support

Covered by BigBattery's 12-year manufacturer warranty, backed by lifetime USA-based technical support.

Common questions

How many NEXUS units do I need?

Size to your daily consumption: one unit (15 kWh) carries an efficient cabin or essential circuits overnight; two (30 kWh) suits a household that cycles the bank daily; three (45 kWh) covers full-size homes and cloudy stretches. You can start with one and add units later.

Which inverter should I pair it with?

Any compatible 48V off-grid or hybrid inverter. For pre-matched systems with communications configured, see our NEXUS kits with the EG4 6000XP, EG4 12000XP V2, APEX 6.5K, and APEX 10K.

How does LiFePO4 handle cold weather?

It discharges reliably in freezing temperatures, but the BMS restricts charging below freezing to protect the cells — install the cabinet in an insulated or conditioned space for year-round charging.