NEXUS + APEX-6.5K Off-Grid System (AVAILABLE FOR PRE-ORDER)

Product Summary:

AVAILABLE FOR PRE-ORDER

Meet the APEX 6.5K off-grid hybrid inverter engineered for true energy independence. Delivering split-phase 120/240 V at 50/60 Hz with clean, pure sine-wave output, APEX pairs flawlessly with modern LiFePO₄ banks and accepts both solar and generator inputs for seamless, all-day autonomy. An 80A pass-through keeps large appliances and critical loads humming, while wide operating temps and an outdoor-ready enclosure mean reliable performance in real-world conditions. Installer-friendly bottom-entry wiring and smart protections round out a system that’s rugged, efficient, and ready to power your cabin, homestead, or remote residences to deliver the ultimate source of energy independence.

NEXUS + APEX-6.5K Off-Grid System (AVAILABLE FOR PRE-ORDER)

$4,535.00

SKU# K0191

Choose Your Inverter Option*

EG4 18kPV EG4 FlexBoss18 EG4 FlexBoss21 None

Choose Your Battery Option*

BigBattery ETHOS EG4 280Ah All Weather EG4 280Ah Indoor EG4 314Ah Indoor None

Choose Your Inverter Option*

APEX-6.5K APEX-10K EG4 6000XP EG4 12000XP None

Choose Your Battery Option*

BigBattery NEXUS BigBattery ETHOS BigBattery HUSKY2 INV EG4 280Ah All Weather EG4 280Ah Indoor None

Choose Your ESS Configuration*

1x Inverter

Standard

2x Inverter

Large

3x Inverter

3 Phase

SKU: K0191-V

Items Included

Available for Pre-Order:
Orders placed today will ship following the official product launch at the end of December.

Quantity:

Battery QTY

Inverter QTY

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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

*For the APEX-10K, single AC input supports either grid or generator (not simultaneously).

Battery Downloads

SKU#:K0191, K0192, K0193, K0194, K0195

Spec Sheet:

DOWNLOAD

User Manual:

DOWNLOAD

Battery Specifications

Battery Specifications:NEXUS 15KWh

System Voltage:48V

Nominal Voltage:51.2V

Chemistry:LiFePO4

Usable Energy (kWh):15kWh

Ah Capacity:300Ah

Cell Configuration:16S1P

Max Continuous Discharge Current:140A

Max Continuous Power:7.6kW

Max Discharge Peak Current:270A(1s)

Max Charge Current:140A

Charging Voltage Range:53.5V-57.6V

Operating Voltage Range:48V-57.6V

Max Charge Voltage:57.9V

Suggested Low Voltage Cutoff:50.8V

Charge Temp Range:32°F to 113°F

Discharge Temp Range:-4°F to 113°F

Optimal Discharge Temp:59°F to 95°F

Storage Temp Range (SoC >50%):(1 month-4°F ~ 113°F | 3 months: -4°F ~ 95°F | 6 months: -4°F ~ 77°F)

Humidity Range:10%-95% (No Condensation)

Weight (lbs):~315 lbs

Dimensions (WxHxD):19.7 x 27.5 x 15.7 in (500×700×400 mm)

Altitude Limit:<2000m

Max Connections:15 in parallel (up to 225kWh)

Communications:RS485 / RJ45 / CAN

Protection Rating:IP54

Installation:Indoor Floor-standing

Inverter Downloads

SKU#:K0191, K0192, K0193, K0194, K0195

Spec Sheet:

DOWNLOAD

User Manual:

DOWNLOAD

Inverter Specifications

Document Title:APEX-6.5K & APEX 10K INVERTER SPECIFICATIONS

Brand:BigBattery

Model:APEX-6.5K / APEX-10K

Section:Inverter output

Rated Output Power:APEX-6.5K: 6,500W; APEX-10K: 10,000W

Max. Output Power:APEX-6.5K: 13,000VA; APEX-10K: 20,000VA

Rated Output Voltage:120/240 Vac (single-phase / split-phase)

Load capacity of motors:APEX-6.5K: 4 HP; APEX-10K: 6 HP

Rated Frequency:50/60Hz

Output Wave:Pure sine wave

Switching Time:10ms (typical value)

Section:Battery

Battery Type:Lithium-ion battery / lead-acid battery / user-defined battery

Rated Battery Voltage:48V

Voltage Range:40–60Vdc

Max. Solar Charging Current:APEX-6.5K: 140A; APEX-10K: 200A

Max. Grid / Generator Charging Current:APEX-6.5K: 80A; APEX-10K: 120A

Max. Hybrid Charge Current:APEX-6.5K: 140A; APEX-10K: 200A

Section:Solar input

No. of MPPT:1 + 1

Max. Input Power:APEX-6.5K: 5,000W + 5,000W; APEX-10K: 5,000W + 5,500W

Max. Input Current:APEX-6.5K: 18A + 18A; APEX-10K: 22A + 22A

Max. Open Circuit Voltage:550Vdc + 550Vdc

MPPT Voltage Range:125–450Vdc

Section:Grid / Generator input

Input Voltage Range:65–140Vac

Input Frequency Range:50/60Hz

Bypass Overload Current:APEX-6.5K: 40A; APEX-10K: 63A

AC Inputs:APEX-6.5K: 2 inputs (Grid & Generator); APEX-10K: 1 input (Grid or Generator)

Section:Efficiency

Max. Efficiency:99.9%

MPPT Tracking Efficiency:APEX-6.5K: 93%; APEX-10K: 92%

Parallel Capacity:Up to 6 units (more than 3 units in parallel can form a three-phase output)

Section:General data

Dimension:APEX-6.5K: 25.51 × 16.14 × 5.51 inches; APEX-10K: 28.46 × 17.64 × 5.91 inches

Weight:APEX-6.5K: 48 lbs; APEX-10K: 62 lbs

Protection Degree:IP20 (indoor only)

Temperature:14–131°F, derate above 113°F

External Module (Optional):Wi-Fi / GPRS

Certificate:UL1741 / RoHS / EN61000-6-1 / EC61000-6-3 / FCC Part15 Class B / IEC62109-1 / IEC62109-2

Noise:<60dB

Cooling Method:Intelligent fan

Warranty:5 years

Communication:RS485 / CAN / USB / Dry contact

Integrated Circuit Breaker:Utility / Load / Battery / PV

Section:Overload protection

Overload protection behavior:After overload protection is enabled, the inverter output will be restored after 3 minutes, and after 5 times of overload, the output will be off until the inverter is restarted. (102% < APEX-10K load < 110%): an error will be reported and the output will be turned off after 5 minutes. (110% < load < 125%): an error will be reported and the output will be turned off after 10 seconds. Load > 125%: an error will be reported and the output will be turned off after 5 seconds.

Protection features:Has PV input current limiting protection, PV input over-voltage protection, PV night reverse current protection, AC input over-voltage protection, AC input under-voltage protection, battery over-voltage protection, battery under-voltage protection, battery over-current protection, AC output short-circuit protection, heat sink over-temperature protection, inverter over-load protection.

12 Year Warranty