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Fox H3 Smart 8.0KW 3ph Hybrid Inverter
Fox ESS Fox H3 Smart 8.0KW 3ph Hybrid Inverter
Fox H3 Smart 8.0KW 3ph Hybrid Inverter
Fox ESS H3 Smart — Three trackers, a 100 – 800 V battery window, and silent operation to 10 kW.
The H3 Smart is the current three-phase residential hybrid and the improvements over the older H3 are where they count. Three MPP trackers instead of two, a battery window that opens at 100 V instead of 180 V, and 50 A of battery current instead of 26 A — so the same stack charges and discharges nearly twice as fast.
About the Fox ESS H3 Smart
A wide battery window matters more than it sounds. A stack that can operate down to 100 V can be a smaller stack, which means a customer can start with two or three modules and add more later rather than being forced into a large minimum on day one.
The 5 kW to 10 kW models are convection cooled and quoted under 40 dB, which is quiet enough for a utility room. Only the 12 kW uses a fan.
Which battery does this inverter take?
This inverter takes High voltage Fox ESS stacks.
This model has a battery voltage window of 100 – 800 V, a maximum charge or discharge current of 50.0 A, BMS communication over CAN.
A stack is one master module, which carries the BMS, plus matching slave modules of the same type. Module types are never mixed in one stack. These are the counts this inverter is listed for — Product Compatibility Fox ESS UK 2026, the module count range for this inverter family:
What we stock that fits this inverter:
String design, battery limits and what is in the box
The details that decide whether this unit suits the job:
- Battery window 100 – 800 V, LFP, 50 A maximum charge or discharge, CAN.
- Note the minimum battery voltage at full AC load: 108 V on the 5 kW rising to 250 V on the 12 kW. A small stack will not deliver full output on a large inverter.
- Three MPP trackers, one string each, 20 A per tracker, 25 A Isc, 10 kW maximum per tracker.
- 1,000 V maximum DC (950 V maximum operating), 620 V nominal, 140 V start-up, 120 – 950 V MPPT window.
- DC switch fitted as standard. AFCI optional. Surge protection Type II on both sides.
- 5 kW to 10 kW are convection cooled under 40 dB; the 12 kW uses fan cooling at under 55 dB.
- SG Ready and ripple control supported; Ethernet, RS485 EMS, Wi-Fi + LAN + Bluetooth, 4G optional.
- 600 × 450 × 226 mm, 34 kg, IP65.
Where this hybrid earns its place
The H3 Smart is specified most often for these jobs.
Things worth knowing about this listing
- Wi-Fi is built in and a meter is included.
- Register the installation with Fox ESS at fox-ess.com to activate the 10-year warranty. Unregistered, the cover is 5 years.
Fox ESS H3-8.0-Smart technical data
Ordered with this inverter more often than anything else
A hybrid is the middle of a system, not the whole of it. These are the parts our customers add most often:
Questions we get asked about this inverter
What does the minimum battery voltage at full load mean?
It is the stack voltage below which the inverter cannot deliver its full AC output. On the 12 kW it is 250 V, which means a small stack will limit output even though it connects and works. Size the stack to the inverter, not just to the kWh you want.
Three trackers — do I need them?
If your roof has three usable planes, yes. If it has one, you are paying for capability you will not use, and the H3 range may suit better.
Is it silent?
The 5 kW to 10 kW models are convection cooled and quoted under 40 dB. The 12 kW is fan cooled at under 55 dB.
What is SG Ready?
A standard heat pump control interface. The inverter can tell the heat pump when there is surplus solar, so the house stores heat instead of exporting cheaply.
Which battery?
Fox high voltage stacks in the 100 – 800 V window. The CQ7 range for H3 Smart is 3 to 12 modules.
Documents, advice and trade pricing
Every datasheet, certificate, installation manual and warranty document we hold for this product is in the Documents tab below. See the rest of our hybrid inverter range, our batteries and our solar panels, or email sales@clearraysolar.com if you would like us to check a battery pairing or a string design before you order.
Build your complete solar system
Everything you need in one place.
- Inverters
- Batteries
- Mounting Systems
- Cabling & Accessories
- Protection Devices
Delivery times vary by region:
- UK — 1-2 business days
- Highlands & Islands — 1-2 business days
Returns accepted within 14 days of delivery for unused items in original packaging.
