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Big Battery

BigBattery EG4 FlexBOSS18 Hybrid Solar Inverter | 18kW PV / 13kW AC | Split-Phase | 2-MPPT | Scalable | Remote Wi-Fi Monitoring

SKU INV031
$4,116.48
$4,116.48
Free Shipping Contiguous USA
Warranty Info View coverage → 30-Day Returns View terms →
Questions? Give us a call +1 239-310-4096
In stock

Estimated Delivery: 4-7 Business Days from Order Date

Free Standard Shipping on All Orders to the Contiguous USA

30 Day Return Policy with 25% restocking fee applies to change-of-mind returns. See full policy

Estimated shipping time

You can typically expect your items to arrive within 4–7 business days, depending on your location and product availability.

What is your Return Policy?

At Wildhaven Curator, 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.
  • If you’re returning an item because you changed your mind, you’ll be responsible for return shipping fees.

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—including any original shipping costs.

4. Changed Your Mind?

If you no longer want the item, you can return it within 30 days—as long as it's unused, in its original packaging, and in resellable condition. You’ll need to handle the return shipping, and once we receive and inspect it, we’ll refund the product cost (excluding shipping).

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.

If it’s been over 10 business days since your refund was approved and you still don’t see it, contact us at support@wildhavencurator.com and we’ll look into it immediately.

6. Restocking Fees

In some cases, a restocking fee may apply depending on the item and return reason. If applicable, we’ll clearly communicate this during your return request process.

Big Battery

BigBattery EG4 FlexBOSS18 Hybrid Solar Inverter | 18kW PV / 13kW AC | Split-Phase | 2-MPPT | Scalable | Remote Wi-Fi Monitoring

SKU INV031
$4,116.48
BigBattery EG4 FlexBOSS18 Hybrid Solar Inverter | 18kW PV / 13kW AC | Split-Phase | 2-MPPT | Scalable | Remote Wi-Fi Monitoring
Warranty & Support Big Battery

At Wildhaven Curator, we’re here to help with warranty questions about your BigBattery purchase. Our team can help identify the applicable coverage and coordinate manufacturer support.

Manufacturer Warranty Overview

Coverage depends on the product, purchase date, and applicable manufacturer terms. BigBattery provides lifetime technical support and automatically records battery warranties through serial numbers and QR codes.

Coverage and Duration

• BigBattery Batteries: Purchases after October 2024 carry 12-year repair/replacement coverage for material and workmanship defects.

• Earlier Battery Purchases: Purchases before October 2021 carry three-year coverage; purchases from October 2021 through October 2024 carry ten-year coverage.

• BigBattery Chargers and Accessories: One-year coverage from purchase for qualifying defects under normal use.

• BigBattery APEX-6.5K and APEX-10K Inverters: Five-year limited warranty. Contact us for model-specific eligibility, exclusions, and service arrangements.

• Other Manufacturers: Products branded EG4, Sol-Ark, Victron, Growatt, AIMS, or another manufacturer follow that manufacturer’s warranty.

Battery Warranty Service

BigBattery assesses returned batteries before approving service. Repairs or refurbished replacements may be provided.

If a new replacement is provided, beginning in year two, the customer may owe one-twelfth of its cost per year of ownership.

Capacity-loss claims below 25% are excluded. Manufacturer capacity testing is free; results determine eligibility.

Conditions and Exclusions

Battery exclusions include misuse, improper installation, environmental damage, improper charging, over-discharge, and unauthorized modification/disassembly.

If charge falls below 10%, recharge within 48 hours. Contact BigBattery immediately if charging is impossible.

Charger coverage excludes misuse, physical damage, unauthorized work, incompatible equipment, and operation outside specifications. IP65 charger coverage is nontransferable; repaired/replacement chargers retain the original warranty dates.

Battery Warranty Transfers

• Stationary batteries must remain at the original location; ownership-transfer documentation must be emailed within 30 days.

• Mobile batteries must remain in the original vehicle/system, with original purchase proof and a documented ownership chain.

How to Submit a Warranty Inquiry or Claim

  1. Email support@wildhavencurator.com with your order number and proof of purchase.
  2. Include the product model, serial number, issue description, and available photographs.
  3. Our team can help coordinate troubleshooting with BigBattery.
  4. Obtain return instructions before shipping and follow the required packaging procedure.

Manufacturer support: Support@BigBattery.com
Manufacturer phone: (818) 280-3091

Shipping, Labor, and Related Costs

• Battery claims: Eligible first-year claims receive round-trip shipping within the continental U.S.; customers pay both directions afterward. Disconnection, service interruption, and repacking are excluded. International customers pay shipping.

• IP65 charger claims: Customers prepay shipment to the manufacturer. Confirm other shipping costs before returning.

• APEX claims: Contact us to confirm freight, labor, and service costs before arranging work.

Warranty Assistance

For help understanding coverage or coordinating support, contact Wildhaven Curator:

Email: support@wildhavencurator.com
Phone: +1 239-310-4096

Need help with this product? support@wildhavencurator.com
+1 239-310-4096

This hybrid solar inverter manages solar, battery, and grid power for residential and commercial energy systems. It supports up to 18,000W of solar input and split-phase operation for grid-tied, hybrid, and off-grid installations.

Dual MPPTs accommodate multiple solar strings, while 90A grid feed-through supports connected loads. Pairing with a compatible energy management gateway adds smart load management, AC coupling, and generator support.

Wi-Fi connectivity, remote monitoring, and mobile alerts provide visibility into system performance. Rapid shutdown, ground fault protection, and arc fault protection support electrical safety, while parallel operation allows system expansion

Key Features

  • Flexible Operation: Supports grid-tied, hybrid, and off-grid installations.

  • Dual MPPTs: Provides 2 inputs per tracker.

  • Grid Feed-Through: Supports up to 90A AC bypass.

  • Energy Management: Supports peak shaving and intelligent power distribution.

  • Remote Access: Wi-Fi monitoring and mobile alerts.

  • Safety Functions: Rapid shutdown, ground fault protection, and arc fault protection.

  • Scalability: Supports up to 10 parallel connections.

Specifications

  • Nominal AC Voltage: 120/240VAC | 120/208VAC (L1/L2/N required)

  • Frequency: 60 Hz default | 50 Hz

  • Maximum AC Input Power: 13000W

  • Maximum AC Bypass: 90A

  • AC Operating Voltage Range: 180–270VAC

  • Power Factor: 0.99 at full load

  • Reactive Power Adjustment Range: -0.8–0.8 Leading Adjustable

  • Total Harmonic Distortion: <5% at full load

  • Transfer Time: 20ms default | 10ms configurable | 20ms parallel

  • Peak Power: 20000W for 0.5 sec | 15000W for 1 sec | 12500W for 6 min | 11000W for 12 min

  • Number of MPPTs: 2

  • Inputs per MPPT: 2 for MPPT 1 | 2 for MPPT 2

  • Maximum Usable PV Input Current: 26A for MPPT 1 | 26A for MPPT 2

  • Maximum Short-Circuit Input Current: 31A for MPPT 1 | 31A for MPPT 2

  • DC Input Voltage Range: 100–600VDC

  • Startup Voltage: 200VDC

  • MPPT Operating Voltage Range: 120–440VDC

  • Nominal MPPT Voltage: 360VDC

  • Maximum Recommended PV Input: 18000W

  • Maximum Efficiency, PV to Grid: 97.5%

  • Maximum Efficiency, PV to Battery: 94.5%

  • Maximum Efficiency, Battery to Grid: 94%

  • Idle Consumption: <65W

  • Nominal Battery Voltage: 48VDC

  • Battery Voltage Range: 40–60VDC

  • Maximum Charge / Discharge Power: 10000W

  • Recommended Battery Capacity per Inverter: >300Ah

  • Operating / Storage Temperature: -13°F–140°F (-25°C–60°C)

  • Operating Altitude: <6,561 ft (2000 m)

  • Relative Humidity: 0–100%

  • Typical Noise Emission: <50dB at 3 ft

  • Design Topology: High frequency / Transformerless

  • Protection Rating: IP65 / NEMA 4X

  • Communications: RS485 / CANBus / WiFi / 4G

  • Maximum Parallel Connections: 10

Size Guide

  • Depth: 11.2 in

  • Width: 22.8 in

  • Height: 30.5 in

  • Weight: 115 lbs (52 kg)

Compatibility

Compatible With: 48V battery systems and AC-coupled installations.

UL 9540 Systems with Closed-Loop Communication — Grid-Tied and Off-Grid: BigBattery ETHOS and EG4 batteries.

Compatible Gateway: EG4 GridBOSS MID, sold separately, for advanced system control.

Warranty

Warranty: 10-year EG4 manufacturer warranty.

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