Fox ESS · Solar inverter model
AC1 AC charger
Fox ESS AC1 G2 is a single-phase AC-coupled battery inverter in UK-advertised 3 to 6 kW power classes; despite its name, it is not an EV chargepoint.
Specifications
| Specification | Value |
|---|---|
| Type | AC-coupled battery inverter |
| Supply phases | single |
| Rated AC power (kW) | 3, 3.68, 5 and 6 in the current UK range |
| Battery-voltage range (V) | 80 to 480 |
| Maximum efficiency (%) | 97.01 to 97.08, depending on rating |
| Battery compatible | yes |
| Backup capable | yes; EPS changeover below 10 ms |
| Warranty (years) | 5 from installation, capped at 65 months from manufacture; extensions conditional |
| IP rating | IP65 |
| Euro efficiency (%) | 95.26 to 96.33, depending on rating |
| Maximum battery current (A) | 40 |
| EPS changeover (ms) | <10 |
Fox ESS AC1 G2 is an AC-coupled battery inverter. Fox ESS uses the term AC charger for equipment that charges a home battery from the AC side of an installation. It is not an EV charger.
UK and global AC1 G2 ratings
The current UK marketing copy rounds one model’s nominal rating. The June 2026 global H1 G2 and AC1 G2 table provides the precise value and adds 2.5, 4 and 4.6 kW variants.
| Full AC1 G2 code | Rated AC output | Current UK range |
|---|---|---|
AC1-2.5-E-G2 |
2.5 kW | no |
AC1-3.0-E-G2 |
3 kW | yes |
AC1-3.7-E-G2 |
3.68 kW | yes, advertised as 3.7 kW |
AC1-4.0-E-G2 |
4 kW | no |
AC1-4.6-E-G2 |
4.6 kW | no |
AC1-5.0-E-G2 |
5 kW | yes |
AC1-6.0-E-G2 |
6 kW | yes |
Wireless-LAN variants add -WL to these codes. That ending is part of the model identity.
AC1 shares its platform and AC-side ratings with the H1 hybrid inverter, but it does not have the H1’s solar inputs. A compatible Fox battery can therefore be connected on the AC side of a new or existing generation system. Solar generation and battery conversion remain separate, so energy travelling from PV into the battery passes through both the solar inverter and AC1.
Battery pairing and EPS
The battery must appear on the compatibility information for the exact AC1 generation and firmware. A voltage inside the permitted window is not enough on its own; support must cover the complete inverter and battery codes and their current firmware.
The EPS changeover figure describes the inverter function. The protected-load arrangement remains a separate part of the system design.
The complete code should be recorded because older AC1 products and current G2 models have different documents. The AC1 family name alone does not select the matching datasheet, firmware instructions or battery-compatibility record.
Related entries
Manufacturer and reference sources
Brand
Reference type
Solar inverter model
Last reviewed
31 Jul 2026
Current status
Current in the manufacturer's UK range.