Product Summary:
The BigBattery APEX 6.5K + NEXUS™ Off-Grid System is a complete, high-performance energy solution designed for reliable off-grid power and energy independence. Combining the APEX 6.5K hybrid inverter with the NEXUS 48V 15kWh LiFePO₄ battery, this system delivers dependable, efficient energy for homes, cabins, and remote installations.
The APEX 6.5K provides split-phase 120/240V pure sine-wave output, supporting both everyday appliances and heavy loads, while seamlessly integrating solar and generator inputs for continuous operation. Paired with the scalable NEXUS battery system (expandable up to 225kWh), this setup ensures long-lasting, maintenance-free energy storage with consistent performance.
Built with advanced battery protection, safe lithium technology, and U.S.-supported engineering, this system is ideal for off-grid living, backup power, and energy security in demanding environments.
Ships From: Texas, USA
Warranty: 12 Years (Battery), 5 Years (Inverter)
Support: Lifetime USA-Based Tech Support
Compatibility
Integrated & Optimized System (Closed-Loop Communication):
- APEX 6.5K Hybrid Inverter + NEXUS 15kWh Battery
Expandable Design:
- Scale battery storage from 15kWh up to 225kWh
- Supports solar + generator input configurations
- Designed for off-grid and backup power applications
Key Features
- Complete Off-Grid System – Inverter + battery solution designed to work seamlessly together
- 6.5kW Split-Phase Output – Powers 120/240V loads including large appliances
- 15kWh LiFePO₄ Battery – Safe, high-capacity energy storage with long lifespan
- 6,000+ Cycle Life – Built for years of daily use and long-term savings
- Solar + Generator Ready – Flexible power input for continuous energy availability
- 80A Pass-Through – Supports high-demand loads and critical circuits
- Advanced BMS Protection – Multi-layer protection for safe and reliable operation
- Modular Expansion – Easily scale storage capacity as energy needs grow
- UPS Backup Capability (15–30ms) – Seamless transition during outages
- Indoor-Rated Design – Intended for installation in protected environments
- Maintenance-Free Operation – No routine servicing required
A reliable, scalable off-grid energy system built for performance, flexibility, and long-term independence—backed by U.S.-based support you can trust.
NEXUS + APEX-6.5K Off-Grid System
Battery Selected
1× NEXUS
Total Capacity
15 kWh
Inverter Selected
1× APEX-6.5K
Input / Output
10 kW / 6.5 kW
Choose Your ESS Configuration*
1x Inverter
Standard
2x Inverter
Large
3x Inverter
3 Phase
Introducing The APEX Inverter Series
Meet the BigBattery APEX Off-Grid Hybrid Inverter Series (6.5K & 10K)—engineered for true energy independence with two power-class options to match your build. Both models deliver split-phase 120/240V at 50/60 Hz with clean, pure sine-wave output, pairing seamlessly with modern LiFePO₄ battery banks for stable, efficient performance. Designed for real-world autonomy, APEX supports solar and generator inputs so you can stay powered day and night, season after season.
Built to handle demanding loads, the APEX Series features an 80A pass-through to keep large appliances and critical circuits running smoothly, while wide operating temperatures and an outdoor-ready enclosure provide dependable performance in harsh conditions. With installer-friendly bottom-entry wiring and intelligent protections baked in, APEX is a rugged, efficient, and practical backbone for cabins, homesteads, remote residences, and off-grid properties—delivering a streamlined path to reliable, all-day power.
Whole-Home Split-Phase Power
Delivers clean, pure sine-wave electricity to run larger appliances and essential circuits with confidence. Ideal for cabins, homesteads, and off-grid homes that need true 120/240V performance.
Solar Ready Set-Up
Designed to accept both solar and generator inputs on APEX-6.5K so you can stay powered day and night. When sunlight dips, your generator can seamlessly keep the system charging and your loads running.
Off-Grid Reliability
Installer-friendly bottom-entry wiring and built-in protections help keep your setup clean, safe, and dependable for any remote residences. Inputs vary on both inverters, read the specification sheet for more information on inputs between both inverters.
Go Big On Power
The APEX inverter series & NEXUS battery kit paired together is the ultimate solar set up for all off-grid enthusiasts, whether its a cozy log cabin, modest tiny home or a vast ranch, this ESS was designed to ensure your energy independence, protect yourself from outages & blackouts and stay powered.
| INVERTER INPUTS | APEX-6.5K | APEX-10K |
|---|---|---|
| Grid | yes | yes |
| Load | yes | yes |
| Generator | yes | yes* |
| BAT – | yes | yes |
| BAT + | yes | yes |
| PV | yes | yes |
| Parallel Connection | yes | yes |
| USB | yes | yes |
| CT | yes | no |
| WiFi | yes | yes |
| RS485/CAN | yes | yes |
| Dry Contact | yes | yes |
DOWNLOADBattery Specifications
Inverter Specifications
At BigBattery, we stand behind the quality and reliability of our products. Our warranty coverage is designed to give you confidence and peace of mind with every purchase.
- Battery: Covered by a 12-Year Limited Warranty
- Inverter: Covered by a 5-Year Limited Warranty
For full details on coverage, terms, and conditions, please visit our Policy Page.
Introducing The APEX Inverter Series
Meet the BigBattery APEX Off-Grid Hybrid Inverter Series (6.5K & 10K)—engineered for true energy independence with two power-class options to match your build. Both models deliver split-phase 120/240V at 50/60 Hz with clean, pure sine-wave output, pairing seamlessly with modern LiFePO₄ battery banks for stable, efficient performance. Designed for real-world autonomy, APEX supports solar and generator inputs so you can stay powered day and night, season after season.
Built to handle demanding loads, the APEX Series features an 80A pass-through to keep large appliances and critical circuits running smoothly, while wide operating temperatures and an outdoor-ready enclosure provide dependable performance in harsh conditions. With installer-friendly bottom-entry wiring and intelligent protections baked in, APEX is a rugged, efficient, and practical backbone for cabins, homesteads, remote residences, and off-grid properties—delivering a streamlined path to reliable, all-day power.
Whole-Home Split-Phase Power
Delivers clean, pure sine-wave electricity to run larger appliances and essential circuits with confidence. Ideal for cabins, homesteads, and off-grid homes that need true 120/240V performance.
Solar Ready Set-Up
Designed to accept both solar and generator inputs on APEX-6.5K so you can stay powered day and night. When sunlight dips, your generator can seamlessly keep the system charging and your loads running.
Off-Grid Reliability
Installer-friendly bottom-entry wiring and built-in protections help keep your setup clean, safe, and dependable for any remote residences. Inputs vary on both inverters, read the specification sheet for more information on inputs between both inverters.
Go Big On Power
The APEX inverter series & NEXUS battery kit paired together is the ultimate solar set up for all off-grid enthusiasts, whether its a cozy log cabin, modest tiny home or a vast ranch, this ESS was designed to ensure your energy independence, protect yourself from outages & blackouts and stay powered.
| INVERTER INPUTS | APEX-6.5K | APEX-10K |
|---|---|---|
| Grid | yes | yes |
| Load | yes | yes |
| Generator | yes | yes* |
| BAT – | yes | yes |
| BAT + | yes | yes |
| PV | yes | yes |
| Parallel Connection | yes | yes |
| USB | yes | yes |
| CT | yes | no |
| WiFi | yes | yes |
| RS485/CAN | yes | yes |
| Dry Contact | yes | yes |
Battery Specifications
Inverter Specifications
At BigBattery, we stand behind the quality and reliability of our products. Our warranty coverage is designed to give you confidence and peace of mind with every purchase.
- Battery: Covered by a 12-Year Limited Warranty
- Inverter: Covered by a 5-Year Limited Warranty
For full details on coverage, terms, and conditions, please visit our Policy Page.
