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NEXUS 48V 14.3kWH LiFePO4 Battery + EG4 6,000XP Inverter | Off-Grid Home Back-up System

SKU: K0152
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Regular price $4,544.99
Regular price $4,999.00 Sale price $4,544.99
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48V Off-Grid ESS · NEXUS + EG4 6000XP · Indoor System

14.3kWh of Off-Grid Power From a Pre-Matched Battery and Inverter Pair

This system pairs one BigBattery NEXUS 14.3kWh battery with one transformer-free EG4 6000XP inverter into a single closed-loop off-grid setup — 14.3kWh of storage and 6,000W of continuous output, with up to 8,000W of dual-MPPT solar input. It's an indoor installation for both components, built for cabins, homesteads, and off-grid homes, and it scales up to 214.5kWh of storage — or 18kW of combined output — on the same platform if you need more later.

14.3kWhTotal Capacity
6,000WContinuous Output
8,000WMax PV Input
214.5kWhMax Expandable

What's In This System

Two components, pre-matched and sold together.

Qty 1

BigBattery NEXUS 14.3kWh

Floor-standing 48V LiFePO₄ battery, expandable up to 15 units in parallel for 214.5kWh total.

Qty 1

EG4 6000XP Hybrid Inverter

6,000W continuous output in a transformer-free design, with dual MPPT solar input up to 8,000W.

A modern lakeside cabin at sunset showcases the EG4 6,000W 120VAC/240VAC Off-Grid Hybrid Solar Inverter by EG4, featuring prominently an LED display (with crisp clarity rendered in IBM Plex Sans font), smart energy management, robust safety compliance, high efficiency, quiet operation, and scalable output—all presented with smooth border radius styling for a sleek contemporary aesthetic.

What Makes This System Different

14.3kWh NEXUS Battery

LiFePO₄ storage rated for 6,000+ cycles, with a 7.6kW continuous power rating and 270A peak discharge for 1 second.

6,000W Continuous, 12,000W Surge

The EG4 6000XP delivers 6,000W continuously with up to 12,000W of surge headroom (3.5 sec) for motor starts.

Transformer-Free Design

A lighter, more efficient architecture than traditional transformer-based inverters, with less standby power lost as heat.

Dual MPPT, 8kW Solar Input

Two independent MPPT trackers pull up to 8,000W combined, adjusting continuously through the day.

Expandable to 214.5kWh

Up to 15 NEXUS units can run in parallel with additional inverters, for serious long-term capacity growth.

Sub-15ms UPS Transfer

Switches to battery power in under 15 milliseconds, keeping sensitive electronics running through a grid drop without a hard reboot.

6,000+ Cycle Life

The NEXUS battery is rated for years of daily charge and discharge cycles before capacity meaningfully declines.

Advanced BMS Protection

Multi-layer protection on both the battery and inverter for safe, reliable day-to-day operation.

A Pre-Matched Pair, Built for Indoor Installation

Rather than picking a battery and inverter separately and hoping they communicate well together, this system ships as one closed-loop pairing: the NEXUS battery and EG4 6000XP inverter are designed and sold to work with each other directly. The 6000XP's transformer-free design keeps it lighter and more efficient than older inverter architectures, and it switches to battery power in under 15 milliseconds if the grid drops — close to seamless for anything plugged in at the time.

Worth knowing before installing: this is an indoor system on both sides. The NEXUS battery is specified for indoor, floor-standing installation, and the EG4 6000XP is IP20 — neither is rated for direct outdoor exposure. Plan for a garage, utility room, or dedicated power space. In exchange, the platform scales seriously: up to 15 NEXUS units can run in parallel for 214.5kWh of total storage, and additional 6000XP inverters can be added for up to 18kW of combined output on this bundle's available configurations.

Full Specifications

Battery — BigBattery NEXUS 14.3kWh (×1)

Capacity

System voltage 48 V
Nominal voltage 51.2 V
Chemistry LiFePO₄
Usable energy 14.3 kWh
Ah capacity 280 Ah
Cell configuration 16S1P

Charging & Discharge

Max continuous discharge current 140 A
Max continuous power 7.6 kW
Max discharge peak current 270A (1 sec)
Max charge current 140 A
Charging voltage range 53.5–57.6 V

Environmental

Charge temp range 32–113°F
Discharge temp range -4–113°F
Optimal discharge temp 59–95°F
Humidity range 10–95%, no condensation
Protection rating IP54, indoor floor-standing

Physical & Other

Weight ~315 lbs
Dimensions (W×H×D) 19.7 × 27.5 × 15.7 in
Communications RS485, RJ45, CAN
Max connections 15 parallel (214.5kWh)

Inverter — EG4 6000XP (×1)

Output

Output power 6,000 W
Surge capacity 12,000W (3.5s) / 11,000W (5s)
Output voltage 120/240 Vac split-phase
Max continuous output current 25A @ 240V
Switching time <15ms single / <30ms parallel

Solar & Charging

MPPT channels 2 (1 input each)
Max PV array power 8,000W (4,000W/MPPT)
Max discharge current 140 A
Max charge current 125 A

AC Input & Bypass

Max AC input power 9,000 W
AC bypass 50 A
Battery voltage range 46.4–60 Vdc

Physical & Other

Dimensions (D×W×H) 5.25 × 18 × 25.5 in
Weight 52.9 lbs
Protection rating IP20, indoor only
Parallel capacity Up to 16 units

Operating temperature: 32–113°F. Certification: UL1741.

Other Configurations Available

This same NEXUS and EG4 6000XP platform is sold in several sizes. The row below highlighted in your brand color is the configuration this page describes — everything else is shown for reference if a customer needs a different scale.

Tier Inverters Batteries Capacity Max Output
1x Inverter 14.3 kWh 6 kW
1x Inverter 28.6 kWh 6 kW
1x Inverter 42.9 kWh 6 kW
2x Inverter 28.6 kWh 12 kW
3x Inverter 42.9 kWh 18 kW

At sunset, a modern home equipped with rooftop solar panels is shown alongside a feature list for the BigBattery NEXUS 48V 14.3kWh LiFePO4 Battery + EG4 6,000XP Inverter | Off-Grid Home Back-up System. Key attributes—performance, protection, design, scalability, chemistry, and applications—are each represented with blue icons and concise descriptions. The presentation utilizes a clean font family for readability, subtle box shadow effects for added depth, and gently rounded borders that enhance the system’s contemporary visual appeal.

A graph illustrates battery prices dropping from $830/kWh in 2018 to $199/kWh projected in 2025. To the right, BEST PRICE IN AMERICA appears prominently in bold IBM Plex Sans font. Nearby, the BigBattery NEXUS 48V 14.3kWh LiFePO4 Battery + APEX-10K Inverter | Off-Grid Home Back-Up System is showcased as a Low-Cost Leading Off-Grid LiFePO4 Battery—spotlighting its advanced Nexus 10k model and a modern interface designed with CSS variables for enhanced user experience.

Common Questions

What exactly is included in this system?

One BigBattery NEXUS 14.3kWh battery and one EG4 6000XP hybrid inverter, sold as a pre-matched closed-loop pair — 14.3kWh of storage and 6,000W of continuous output.

Can this system be installed outdoors?

No — both components are indoor-rated. The NEXUS battery is specified as indoor floor-standing, and the EG4 6000XP inverter is IP20. Plan for a garage, utility room, or dedicated indoor power space.

How is this different from the APEX-based NEXUS bundles?

The EG4 6000XP is a transformer-free design, which trims weight and standby losses compared to the APEX inverters' transformer-based construction, and it switches to battery power in under 15ms if the grid drops. It also parallels up to 16 units on its own platform, well beyond the APEX line's 6-unit limit, for systems that need to scale further.

Will this run my entire house?

It depends on your total connected load. At 6,000W continuous (12,000W surge) it covers most efficient homes and cabins comfortably, but a full load calculation is worth doing before sizing your system — especially with well pumps, electric heat, or several large appliances running together.

Can I expand this system later?

Yes — up to 15 NEXUS battery units can run in parallel for 214.5kWh of total capacity, and the EG4 6000XP itself parallels up to 16 units for more combined output.

What's the warranty on this system?

The NEXUS battery carries a 12-year manufacturer's warranty and the EG4 6000XP inverter carries a 10-year manufacturer's warranty — two separate coverage periods for the two components.

Do I need a licensed electrician to install it?

Given the voltages and currents involved, installation should be handled by a qualified, licensed electrician or solar installer familiar with your local code requirements.

Documents & Downloads

Battery — BigBattery NEXUS

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Order Confirmation:

Upon completing your order, you will promptly receive an email confirming the order placement, indicating that we have received your order and pre-authorized your credit card for the purchase. Our next step is to contact our suppliers to confirm the item's availability and readiness for shipment. Should the item be on backorder or unavailable, we will notify you of the estimated lead time. If the provided lead time is unsatisfactory, we will cancel the pre-authorization and contact you via email or phone. If the item can be shipped within 5 business days, we will proceed with processing the charges and shipping your order.

Incorrect Shipping Information:

In the event of incorrect shipping information provided at checkout, we will make every effort to track down the item using our shipping partners. Please be aware that refunds and returns are not available in such cases. However, we will do our utmost to locate the item. If successful, re-shipping fees of up to 20% of the item's value may apply.

Order Shipment:

If your order is in stock and we have successfully processed your credit card charges, the items will be shipped within five business days from the order date. You will receive tracking information via email within 24 hours of your order leaving the distribution center. Should tracking information not be received within six days of your order, please contact us at +1 (307) 317-7213. The cut off time is 4 pm EST.

Lead time is usually 5-10 business days to receive an order after purchase.

We offer free shipping on all orders and applicable items and brands within the mainland of the US (Hawaii, Alaska, and Overseas Territories are exclusions).

Eco Solar Kits does not ship orders directly to Hawaii, Alaska, or Overseas Territories. Clients needing delivery to these locations must arrange a freight forwarder and enter the forwarder’s address as the shipping address. Eco Solar Kits will then ship the order to the designated freight forwarder under our standard shipping terms.

Typically, orders are processed immediately upon receipt, taking approximately 1-4 business days after order confirmation, payment, and pick-up time to fulfill.

The delivery time via freight carrier may vary between 4-6 business days, depending on your location.

  • The minimum order value required for purchase is $69.
  • We offer convenient courier delivery right to your door.
  • Delivery Services We Use Mainly:
    • FedEx
    • UPS
    • USPS
    • Estes
    • Roadrunner

Shipping Concerns:

To prevent delays, frustration, and additional costs, kindly inform us of any concerns regarding the delivery to your location. It's important to note that the following situations may incur additional costs:

  • Charges imposed by the freight company if an 18-wheeler truck cannot access the delivery location
  • Restrictions on truck height or bridge laws during transportation
  • Deliveries to islands
  • Road or access restrictions
  • Delivery requiring the use of a ferry, train, plane, or additional courier transport

Contact Information:

You can reach us using the contact methods provided below:

Return and refund policy

At D&D Eco Power Goods LLC, we strive to ensure our customers are completely satisfied with their purchases. Our return and refund policies are designed to provide a fair and transparent process based on the delivery date of your item.

Return Eligibility

You have 30 days from the delivery date to initiate a return. To be eligible for a return, the item must meet the following conditions:

  • Unused and packaging intact: The item must be in its original packaging and condition.
  • All tags intact: Any tags must remain attached.
  • Proof of purchase: You will need to provide a receipt or proof of purchase.

Items that do not meet these conditions will not be accepted for return.

Circumstances under which returns are offered

  • Canceling an order: You may cancel your order before it has shipped. A 3% deduction will apply to cover platform fees from the total amount paid.
  • Damaged on arrival: If your item arrives damaged, please file the damage with the shipping carrier and contact us within 24 hours of delivery to assess the issue. We may request photos of the damage.
  • Faulty manufacturing or broken after use: Items with manufacturing defects or that break under normal use are covered under the manufacturer's warranty. Please contact us for guidance.
  • Changed your mind: If you decide to return an item because you changed your mind, please ensure it meets the return eligibility criteria stated above. The client will be responsible for the return shipping costs.
  • Exchanges: To expedite an exchange, return the unwanted item first and place a new order for the desired item.
  • Wrong product received: If you receive the wrong item, please contact us immediately so we can rectify the issue.

How to initiate a return

To begin the return process, please follow these steps:

  • Contact us: Reach out via phone at +1 (307) 317-7213, live chat on the website, or email us at hello@ecosolarkits.com. You can also fill out the contact form on our website.
    • Provide necessary information: Your order number
    • First and last name of the person who paid for the order
    • A brief description of the issue
    • Photos of the product (if applicable, especially for damaged items)
  • Return authorization: You will receive a return authorization from our team. Returns without prior authorization will not be accepted.
  • Return shipping instructions: Eco Solar Kits is responsible for return shipping costs if the return is due to a damaged or incorrect item. In such cases, we will provide the customer with a return shipping label to download and print.
  • If our managers are unable to obtain the shipping address and label from the manufacturer within 15 business days, the customer will receive the shipping label directly from us and should send the products to 1309 Coffeen Avenue STE 1200, Sheridan, WY, 82801, USA.

Refund policy

We prioritize customer satisfaction and aim to provide a seamless refund experience. This refund policy is based on the delivery date of your item to ensure fairness in the return process.

Circumstances under which refunds are offered

  1. If the products never arrived: If your order does not arrive within the expected delivery timeframe, please contact us. We will investigate the issue with the carrier and, if confirmed as lost, process a full refund.
  2. Damaged on arrival: If your item arrives damaged, please notify us within 24 hours of delivery. We may ask for photographs of the damage to facilitate the refund process. Once approved, you will receive a full refund.
  3. Faulty manufacturing or broken after use: Items that exhibit manufacturing defects or break under normal use are covered under our warranty. Please reach out to us with details of the issue, including photos. If the item is confirmed faulty, you will be eligible for a full refund or replacement, depending on your preference.
  4. Changed their mind: If you decide to return an item because you changed your mind, it must be returned in its original, unused condition, following the return policy guidelines. Once the return is approved, you will receive a refund, minus any applicable restocking fees.
  5. Wrong product received: If you receive an incorrect item, contact us immediately. We will provide instructions for returning the wrong product, and once received, you will be eligible for a full refund or exchange for the correct item.

When to expect a refund

Refunds will be processed based on the delivery date of the returned product. Once the manufacturer receives and inspects your returned item, we will notify you regarding the approval or rejection of your refund. If approved, the refund will be processed through your original payment method, typically within 10 days. Please note that it may take some time for your bank or credit card company to process and post the refund.

Additional information

  • Return window extension: The return window is extended to 35 days during the following periods:
    • Orders between Nov 25, 2025, and Nov 30, 2025
    • Orders between Dec 25, 2025, and Dec 31, 2025
  • Restocking fee: Returns not related to damaged items may incur a 25% restocking fee.
  • Refund processing time: The processing time for refunds is approximately 10 days from receipt of the returned item.

Contact information

For any questions or concerns regarding our return or refund policy, please do not hesitate to contact us: