Alpha ESS
Smile 5
Compact, modular, and expandable — the smart choice for homes that want flexibility to grow.
5.7–34.2 kWh
Usable Capacity
0% VAT
Domestic install
10 years battery (from Nov 2024)
Warranty
About the Alpha ESS Smile 5
The Alpha ESS Smile 5 is our most flexible battery solution — a compact all-in-one system comprising a 5kW hybrid inverter and modular LFP (LiFePO4) battery packs that can be stacked to create a system sized precisely to the customer's needs. Starting from a single 5.7kWh battery pack, the Smile 5 can be expanded up to 34.2kWh by adding additional modules — without any hardware changes to the inverter. Alpha ESS is a global manufacturer with over 80,000 systems installed across the UK, and their LFP chemistry offers proven safety, longevity, and performance across a wide temperature range.
Key Features
Modular Expansion
Start with 5.7kWh and add battery modules later without changing the inverter. The same Smile 5 inverter supports up to 6 modules for 34.2kWh total capacity.
LFP Battery Chemistry
Lithium Iron Phosphate is the safest and most stable lithium chemistry — no thermal runaway risk, longer cycle life than NMC, and better performance at temperature extremes found in UK garages.
EPS Backup Mode
Emergency Power Supply mode keeps designated circuits running during grid outages, switching automatically within 20ms — fast enough to keep most appliances running without interruption.
Smart Tariff Integration
Compatible with Octopus Go, Intelligent Go, Agile, and Economy 7. Schedule charge and discharge cycles in the Alpha ESS app to maximise tariff savings automatically.
Outdoor IP65 Rating
IP65 rated for outdoor installation, making it suitable for garages, outbuildings, or exterior walls where indoor space is limited.
Cloud Monitoring
24/7 cloud monitoring via the Alpha ESS app. Track generation, consumption, battery state, and grid interaction in real time from any device.
Why Premier Electrical installs this product
The Alpha ESS Smile 5's modularity is its defining advantage. Customers who want to start with a smaller, more affordable system and expand as their budget or energy needs change — perhaps when they add an EV or heat pump — can do so without replacing their inverter. Its compact wall-mount design fits in tight utility spaces, and Alpha ESS's UK support network is well-established. LFP chemistry is also inherently safer than NMC alternatives, with no thermal runaway risk. For cost-conscious customers who want a tier-one system at a more accessible price point, the Smile 5 is our most recommended battery.
Technical Specifications
| Specification | Value |
|---|---|
| Inverter Power | 5 kW continuous |
| Starting Capacity | 5.7 kWh (1 module) |
| Maximum Capacity | 34.2 kWh (6 modules) |
| Battery Chemistry | LFP (LiFePO4) |
| Round-trip Efficiency | 95%+ |
| Operating Temperature | −10°C to 50°C |
| IP Rating | IP65 (outdoor rated) |
| Depth of Discharge | 96% |
| Smart Tariff Support | Octopus Go, Agile & more |
| Product Warranty | 5 years |
| Battery Warranty | 10 years (from Nov 2024) |
| VAT (domestic) | 0% |
Specifications may vary by model variant. Panel selection is confirmed at survey stage based on your roof, usage, and budget.
Installed Price
From £5,500 installed
0% VAT on domestic installations
Warranty
10 years battery (from Nov 2024)
Registered by Premier Electrical Renewables at point of installation.
NICEIC Approved Contractor
Electrical safety assured
Tesla Certified Installer
For Powerwall & Wall Connector
5 Google Rating
50 verified reviews
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