Fox ESS · 4.03 kWh · 1-phase HV battery slave · type B
Fox ESS ECS4100 4.03kWh HV battery (slave)
A van-stock staple for firms fitting ECS4100 systems, this slave adds 4.03kWh of expansion capacity in the V2 connector B build. It is the unit that turns a single-master installation into a proper bank.
Delivery in 3–5 working days (estimate). The dispatch clock starts at cleared payment.
Description
Carrying a slave or two as standing stock changes how upgrade conversations go: the surveyor can quote an extension knowing the part is already on the shelf rather than on order. Each module adds 4.03kWh under an ECS4100 master, so a tower scales in meaningful jumps without the module count running away. For businesses running several crews, keeping this one part number in stores covers every connector B ECS4100 extension in the book, which keeps purchasing simple and call-backs short.
Specification
| Brand | Fox ESS |
|---|---|
| Part number | FE-HV-ECS-4100 |
| Capacity | 4.03 kWh |
| Phase | Single-phase |
| Condition | New |
| Category | Batteries · Li-ion Battery Pack |
| Delivery method | Pallet freight (UN3480 Class 9 dangerous goods) |
What it pairs with
It works under the ECS4100 master in connector B (FE-HV-ECM-4100), the controlling module every one of these stacks starts from, and has no standalone role. On the communications side the same range is served by Fox HV BMS-V2 hardware, with Fox hybrid inverters as the family match. Slave counts per master vary by model and firmware, so consult Fox ESS's current stacking list when sizing.
An expansion module: it needs an ECS4100 master heading the stack and matches V2 connector B builds. Single-phase ecosystem. For anything this page can't settle, ask the trade desk before ordering or consult a competent installer.
Often bought alongside
Last updated 2026-07-19