The FoxESS Cube is D&R Energy's primary battery storage recommendation for residential and light commercial installations in 2026. Built on Lithium Iron Phosphate (LFP) chemistry with a modular stackable design, the Cube can be configured from a single 2.88kWh module right up to 41.94kWh — making it the most scalable battery in our range. This guide covers everything you need to know about the FoxESS Cube, including installed pricing, how it compares to Tesla Powerwall, and how to choose the right capacity for your home.
Why the FoxESS Cube?
The FoxESS Cube offers three genuine advantages over competing battery systems:
- LiFePO4 (LFP) chemistry: The safest and most thermally stable lithium technology. LFP cells cannot experience thermal runaway — they are safe for installation indoors, in garages, and outdoors (IP65 rated). 6,000+ cycle life means the battery outlasts most solar panel warranties.
- True modularity: Start at 2.88kWh and add modules as your needs grow. Getting an EV next year? Add two modules. Installing a heat pump? Stack further. No need to oversize at installation.
- Open compatibility: The FoxESS Cube works with Growatt hybrid inverters and a wide range of third-party systems — you are not locked into a single ecosystem.
Capacity Options and Typical Use Cases
2.88kWh — Starter Module
A single module is suited to smaller solar systems (3–4 panels) or homeowners who want to dip into battery storage with the intention of adding more later. At this capacity, the battery will typically charge fully by early afternoon and discharge by around 8–9pm. Installed price from approximately £2,800–£3,500 (0% VAT with solar panels).
5.76kWh–8.64kWh — The Most Popular Range
Two or three modules is the configuration D&R Energy most frequently recommends for 2–3 bedroom homes with 8–12 solar panels. This range stores a full afternoon of surplus solar generation and covers most households through the evening and overnight. It is the sweet spot between cost and coverage for the typical South West home.
11.52kWh–17.28kWh — For Larger Homes
Four to six modules suits 3–4+ bedroom homes, particularly those with an EV, heat pump, or high energy demand. This range provides genuine whole-home coverage, with enough buffer to bridge cloudy days and handle overnight EV charging from stored solar.
Up to 41.94kWh — Large Property or Light Commercial
The FoxESS Cube's maximum stack of 41.94kWh is well suited to large rural properties, off-gas grid homes, or light commercial applications where energy independence is a priority. Very few competing products offer this level of scalability in a single battery system.
FoxESS Cube vs Tesla Powerwall 3
- Best value per kWh: FoxESS Cube — modular design means you only buy the capacity you need.
- Best for scalability: FoxESS Cube — stack up to 41.94kWh vs Powerwall's 13.5kWh fixed unit.
- Best for whole-home backup: Tesla Powerwall 3 — 11.5kW built-in inverter handles the whole home automatically.
- Best integrated system: Tesla Powerwall 3 — single unit with built-in solar inverter and backup.
- IP rating: FoxESS Cube IP65 — suitable for outdoor installation where space is limited indoors.
For most South West homeowners, the FoxESS Cube at two or three modules provides the best balance of value, capacity, and room to grow. Read our detailed FoxESS Cube vs Tesla Powerwall comparison for a deeper analysis.
Smart Tariff Compatibility
The FoxESS Cube supports scheduled charging and discharging, making it compatible with all major smart tariffs through the FoxESS app:
- Octopus Go: Schedule charging during the 7.5p/kWh overnight window. Annual saving: approximately £350–£550.
- Octopus Agile: Charge during lowest-priced periods and discharge during peak pricing. Annual saving: £500–£800+.
- Octopus Flux: Charge overnight, export during the peak 16:00–19:00 window. Annual saving: £450–£700.
D&R Energy configures your FoxESS Cube's smart tariff settings as part of every installation. Visit our battery storage page for more information, or call 0800 772 0758 to discuss the right configuration for your home.
