Best Battery Brands for Solar Retrofits in Sussex: GivEnergy vs Tesla Powerwall vs Solax
Written by Green Earth Sussex — NAPIT Approved Electricians serving all of East & West Sussex.
Choosing the right battery brand for your solar retrofit is one of the most important decisions you'll make. The battery market has matured significantly — there are now several excellent options — but they differ meaningfully in capacity, coupling type, backup capability, warranty, and price.
This guide compares the three brands we install most frequently for Sussex homeowners: GivEnergy, Tesla Powerwall, and Solax. We'll give you an honest assessment of each so you can make the right choice for your home.
Quick Comparison
| Feature | GivEnergy | Tesla Powerwall 2 | Solax Triple Power |
|---|---|---|---|
| Capacity options | 2.6–19.9 kWh | 13.5 kWh | 5.8–17.4 kWh |
| Coupling type | AC or DC (hybrid) | AC only | DC (hybrid inverter) |
| Backup power | Yes (with AIO) | Yes (full backup) | Yes |
| Warranty | 10 years | 10 years | 10 years |
| Approx. installed cost | £3,500–£7,000 | £8,000–£10,000 | £4,500–£7,500 |
| Best for | Flexibility & value | Premium backup power | DC-coupled efficiency |
GivEnergy: The Flexible All-Rounder
GivEnergy is a UK-based manufacturer that has become one of the most popular battery brands in the country — and for good reason. Their range covers everything from small 2.6kWh units to large 19.9kWh systems, and they offer both AC-coupled and DC-coupled (hybrid inverter) options.
Why we like GivEnergy
- Modular — start small and add capacity later
- UK-based support and warranty service
- Excellent monitoring app (GivEnergy portal)
- Compatible with most existing solar inverters (AC coupling)
- Strong value for money across the range
Considerations
- Backup power requires the All-in-One (AIO) unit — not all GivEnergy models include this
- Less brand recognition than Tesla for resale purposes
Best for: Most Sussex homeowners wanting a flexible, cost-effective battery retrofit with good UK support. Particularly good if you want to start with a smaller capacity and expand later.
Tesla Powerwall 2: The Premium Choice
The Tesla Powerwall 2 is the most recognisable home battery in the world. At 13.5kWh, it's a single large unit that provides whole-home backup power — meaning when the grid goes down, your entire home keeps running from solar and battery.
Why we like Tesla Powerwall
- Best-in-class whole-home backup power capability
- Seamless switchover during power cuts (milliseconds)
- AC-coupled — works with any existing solar inverter
- Excellent Tesla app with detailed energy monitoring
- Strong brand recognition — adds value to property
Considerations
- Significantly higher cost than comparable alternatives
- Only one capacity option (13.5kWh) — may be oversized for smaller homes
- Longer lead times due to high demand
Best for: Homeowners who prioritise backup power capability, have a larger home with higher energy usage, or want the prestige and resale value of the Tesla brand.
Solax Triple Power: The Efficiency-Focused Option
Solax is a well-established inverter manufacturer that has expanded into battery storage with their Triple Power range. Their batteries are DC-coupled, meaning they require a Solax hybrid inverter — so a retrofit involves replacing your existing solar inverter.
Why we like Solax
- Higher efficiency through DC coupling
- Integrated hybrid inverter and battery from one manufacturer
- Modular battery stacking up to 17.4kWh
- Good value when inverter replacement is needed anyway
Considerations
- Requires inverter replacement — higher total cost if existing inverter is working well
- Less flexible for AC-coupled retrofits
Best for: Homeowners whose existing solar inverter is old or failing, or those who want a fully integrated DC-coupled system with maximum efficiency.
Our Recommendation
For most Sussex homeowners retrofitting battery storage to an existing solar system, GivEnergy offers the best combination of flexibility, value, and UK support. If backup power is your primary concern and budget allows, the Tesla Powerwall 2 is hard to beat. If your existing inverter needs replacing anyway, Solax is worth considering for the efficiency gains.
The right choice ultimately depends on your existing system, energy usage, and priorities. Our team will assess your setup and give you an honest recommendation — not just push the most expensive option.
Battery Retrofit Installations Across Sussex
We install GivEnergy, Tesla Powerwall, and Solax battery systems throughout East and West Sussex. Find your local area page below.
Full list on our Battery Retrofits hub page.
Need Help? Get a Free Quote Today
Our NAPIT approved electricians cover all of East and West Sussex. Call us or request a free no-obligation quote.
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