In this guide
What’s in This Bundle?
The SKU is IG-FOX-H3-15.0kW-CQ7(V6)-41.76kWh-3P-6CTs, and it’s three separate line items packaged as one system:
Inverter
- 1× Fox ESS H3 15.0kW Smart hybrid inverter (FOX-H3-15.0-Smart-6CTs)
- Three-phase, 3 MPPTs, 200% PV oversizing
- Includes 6CT meter, DC injection (DCI) monitoring and WiFi as standard
Battery
- 5× CQ7-S Slave modules (6.96kWh each, LFP)
- 1× CQ7-M-V6 Master unit — also 6.96kWh, carries the BMU and system controller
- Master sits on top of the stack; every CQ7 system needs exactly one
Total: 6 modules × 6.96kWh = 41.76kWh, matching the “CQ7-L6” configuration in Fox ESS’s own datasheet.
This 15kW + 41.76kWh Build
The Standout Number: 100% Depth of Discharge
Fox ESS rates the CQ7 at 100% DOD, meaning the 41.76kWh nominal figure and the usable figure are the same number — no derate to account for, unlike some competing batteries that quote a nominal capacity above what you can actually use.
Footprint: Two Enclosures, Not One
Worth knowing before you plan the install: this is a genuinely large stack. At the L6 configuration (Master + 5 Slaves), the CQ7 tower is 660×360mm footprint and 1,040mm tall, weighing 307.5kg. The H3-15.0-Smart inverter is a separate, wall-mounted unit at 600×450×226mm, 34kg.
| Component | Dimensions | Weight | Mounting |
|---|---|---|---|
| H3-15.0-Smart inverter | 600×450×226mm | 34kg | Wall-mounted |
| CQ7 stack (L6, this build) | 660×360mm, 1,040mm tall | 307.5kg | Floor-standing |
The two units are typically mounted on separate parts of the wall/floor rather than as one column — if you’ve read our GoodWe 40kWh ESA comparison, this is the same two-enclosure pattern we found there for Fox ESS, just at this specific 41.76kWh capacity. Plan for roughly 1.1m of floor-to-top clearance for the battery tower plus separate wall space for the inverter when scoping the install location.
Charge, Discharge & Backup Amps
The CQ7’s own numbers look big: at the L6 (41.76kWh) configuration, the battery stack is rated to 27.65kW at a flat 80A max charge/discharge current and 345.6V nominal stack voltage. That’s genuinely more power than the battery needs to supply for this system, because the H3-15.0-Smart inverter is rated to 15kW nominal (16.5kVA peak) — the inverter, not the battery, is what actually caps how fast this system charges or discharges.
New Install vs AC-Coupled Retrofit
This SKU is built to work either way, which is the main reason we reach for it over other Fox ESS packages:
Either way, the battery side, the rebate eligibility and the specs below are the same — the only thing that changes is how the PV side gets wired in.
Full Spec Table
Inverter — Fox ESS H3-15.0-Smart-6CTs
| Spec | Value |
|---|---|
| Rated AC power | 15kW / 15kVA |
| MPPTs | 3 |
| Max PV oversizing | 200% (up to 30kW array) |
| Max efficiency | ~97.9% |
| Metering | 6CT configuration, included |
| Backup | Built-in EPS port (partial); external ~63A contactor for whole-home |
| Dimensions | 600×450×226mm |
| IP rating | IP65 |
| Standard warranty | 10 years |
Battery — Fox ESS CQ7(V6), L6 configuration
| Spec | Value |
|---|---|
| Nominal / usable capacity | 41.76kWh / 41.76kWh (100% DOD) |
| Per-module capacity | 6.96kWh (1 Master + 5 Slaves) |
| Chemistry | LFP |
| Max charge/discharge current | 80A (flat) |
| Round-trip efficiency | >95% |
| Dimensions (this config) | 660×360mm footprint, 1,040mm tall |
| IP rating | IP65 |
| Scalable to | 97.44kWh (14 modules max) |
| Battery warranty | Reported 12 years — confirm current terms at quote |
Perth & WA Rebates for This System
Same two schemes as any CEC-approved battery, recalculated for 41.76kWh usable. Figures last verified 15 August 2026.
Federal Cheaper Home Batteries Program
14kWh × $151 = $2,114
13.76kWh × $38 = $523
Total: roughly $6,165
WA Residential Battery Scheme
Capped at 10kWh regardless of actual battery size: $130/kWh up to $1,300 for Synergy customers, $380/kWh up to $3,800 for Horizon Power customers.
Stacked together: roughly $7,465 combined for a Perth (Synergy) customer, or $9,965 for a Horizon Power customer in regional WA. See our WA battery rebate guide for full eligibility detail.
Installation Compliance in WA
AS/NZS 5139 governs placement, clearances and mechanical protection for every battery install in Australia. At 307.5kg, the CQ7 tower needs a hard, level, load-rated surface, and if it’s going in a garage or carport where a vehicle could strike it, expect a mechanical barrier like a bollard as part of the job.
Who This System Suits
Right for: large three-phase installs and AC-coupled retrofits
A large three-phase Perth home wanting a genuinely big battery in a new solar install, or a home that already has solar and wants to retrofit serious storage without replacing the existing inverter. The 100% DOD rating and flat 80A charge/discharge current are genuine strengths, and 6CT metering plus DCI monitoring come standard.
Worth weighing: it’s not a compact, single-enclosure system
At 307.5kg and 1,040mm tall for the battery tower alone, plus a separately wall-mounted inverter, this needs proper floor space planned into the job. If footprint is the deciding factor, our GoodWe 40kWh ESA is worth comparing side by side with this one before you commit.
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Frequently Asked Questions
- What’s the difference between the CQ7 Master and Slave modules?
- Both store 6.96kWh, but the Master unit (CQ7-M-V6) also contains the battery management unit and system controller for the whole stack. Every CQ7 system needs exactly one Master plus at least one Slave.
- Can this Fox ESS system be added to existing solar panels?
- Yes. The H3-15.0-Smart supports AC-coupled operation, so it can be installed as a battery-only addition alongside an existing solar inverter, without needing to replace that inverter.
- Does the Fox ESS CQ7 have 100% usable capacity?
- Yes — Fox ESS rates the CQ7 at 100% depth of discharge, so the 41.76kWh nominal figure for this six-module build is also the usable figure.
- Does this system need extra hardware for whole-home backup?
- The H3-15.0-Smart has a built-in EPS port for partial backup out of the box. Covering the entire switchboard typically needs an external changeover contactor, commonly rated around 63A.
- Does this system qualify for WA and federal battery rebates?
- Yes, provided the specific model is on the current Synergy or Horizon Power Supported Solutions list and the install meets VPP enrolment requirements. Both rebates stack.
