We install four battery lines — EnSmart, Sigenergy, Tesla and EcoFlow — which means we spend a lot of surveys answering the same fair question: which one should I actually buy? The honest answer is that each line earns its place for a different kind of household, and the wrong way to choose is by brand recognition alone. Here is how the four compare, using the manufacturers’ published figures, and the questions that decide it for your home.
The four lines at a glance
| Line | Format | Published warranty | Stands out for |
|---|---|---|---|
| EnSmart SolarAll | Hybrid inverter cabinet range (single-phase models published at 3–6 kW) paired with lithium battery packs | Confirmed per configuration at quote stage | The kit in our own installation photography — proven, practical, UK-based manufacturer |
| Sigenergy SigenStor | Modular tower: 6.02 / 9.04 kWh LiFePO4 modules, stackable | 10 years (modules and inverter); 60% usable energy at 10 years or per-module throughput; EV DC module 3 years | The “5-in-One” design — inverter, battery and optional 12.5/25 kW DC EV charging in one unit |
| Tesla Powerwall 3 | Single 13.5 kWh unit, integrated solar inverter; up to 4 units | 10 years; 80% retention at 10 years for UK installs, unlimited cycles for normal home use | Output (configurable up to 11.04 kW) and the strongest published UK retention warranty |
| EcoFlow PowerOcean | Modular: 5 kWh LFP packs; single-phase up to 20 kWh per inverter (6 kW output), three-phase to 45 kWh (12 kW) | 15 years, described as daily use until 70% of original capacity; 6,000+ cycle packs | The longest published warranty of the four, and small 5 kWh growth steps |
Figures from each manufacturer’s published UK/European product and warranty documents; lines change, so we confirm current models and terms with every quote.
EnSmart: the kit you can see in our work
EnSmart Power is a UK-based manufacturer with a long background in power conversion — uninterruptible power supplies as well as solar and storage — and its SolarAll hybrid range combines solar input, battery management and household supply in one cabinet. Its published single-phase SolarAll-H models run from 3 to 6 kW, with higher-power HT-series units above that, paired with EnSmart’s lithium battery packs.
We will be straight with you: EnSmart publishes less consumer-facing specification detail than the three bigger names below, so rather than dress thin brochure data up as a full comparison, we treat EnSmart configurations as a quote-stage conversation — exact inverter model, battery pack size and warranty terms confirmed in writing for your specific system. What we can show is our own track record: the SolarAll cabinets in the photography across this site are systems we fitted. See our EnSmart page for more.
Sigenergy: the one that grows with you
The SigenStor’s pitch is integration and modularity. Battery modules of 6.02 or 9.04 kWh stack in a slim tower beneath a hybrid inverter (3.0–12.0 kW single-phase), connect automatically, and can be joined later by further modules — or a second tower — as your usage grows. It is also the only line here with an optional DC EV-charging module: 12.5 or 25 kW, CCS2, bi-directional and V2X-ready where the vehicle allows, against the 7 kW of a typical home wallbox.
The warranty is 10 years on modules and inverter, with performance warranted at 60% of usable energy at ten years (or a per-module throughput cap, whichever comes first) and an internet connection required to keep the full term. Strong product; read the terms, as you should for every brand here. Full details on our Sigenergy page.
Tesla Powerwall 3: the strongest numbers in one box
The Powerwall 3 stores 13.5 kWh and delivers continuous power configurable up to 11.04 kW, with a solar inverter built in — up to 20 kW of panels connect directly to it. For UK installations Tesla publishes the strongest retention guarantee of the four: 80% of capacity at ten years, with unlimited cycles for solar self-consumption, time-based control and backup. Paired with the Backup Gateway 2 it delivers mature whole-home backup.
The trade-off is granularity: capacity comes in 13.5 kWh strides, so a lightly-loaded home may be buying storage it never cycles. Our detailed look is on our Tesla Powerwall page, and our head-to-head with the SigenStor is here.
EcoFlow PowerOcean: the longest published warranty
EcoFlow’s PowerOcean builds in 5 kWh LFP packs — the smallest step size of the four — with each 800 V pack running its own battery management and DC-DC conversion, an IP65 enclosure, a fire prevention module and self-heating for cold weather. Single-phase systems output up to 6 kW of continuous off-grid power with up to 20 kWh per inverter; three-phase systems reach 45 kWh and 12 kW.
The headline is the 15-year official warranty on EcoFlow’s UK pages — described as daily use until the battery reaches 70% of original capacity — which is five years longer than the other lines here and changes the payback arithmetic for patient owners. The 6 kW single-phase output is the number to check against your peak loads before committing. More on our EcoFlow page.
How to actually choose
Four questions settle most surveys:
- How much do you use after sunset? Pull your smart-meter data — evening and overnight consumption sets the capacity that will actually cycle daily. Buying beyond what you cycle stretches payback for no benefit.
- Is your usage about to change? EV on order, heat pump planned, family growing — modular lines (SigenStor in 6–9 kWh steps, PowerOcean in 5 kWh steps) fit a rising curve; the Powerwall 3 suits usage that is already substantial.
- Does backup matter to you? All four can be designed for it, but output differs — 6 kW on a single-phase PowerOcean against up to 11.04 kW on a Powerwall 3 — and backup must be designed in from the start, not bolted on.
- How do you weigh warranty? Longest term: EcoFlow at 15 years. Strongest retention promise: Tesla’s UK 80% at ten years. Every line’s terms carry conditions — internet connectivity clauses in particular — and we put the actual documents in front of you before you decide.
One thing we deliberately have not compared: price. These manufacturers do not publish UK consumer price lists, and any installer quoting “the price” of a battery without surveying your home is guessing. A fair comparison needs your consumption data, your supply type and your roof — which is what the survey is for.
The no-pressure next step
Bring us a recent electricity bill or your smart-meter data and we will model all four lines against your real usage — capacity, output, warranty and cost side by side, with an itemised quote for the one that fits. If a battery does not stack up for your home yet, we will tell you that too. Request a free quote, call 0204 547 1892, or start with the basics on battery storage.