Tesla Powerwall 3 vs Duracell Dura16: which fits your home?

These are the two battery packages Clearline actually prices: the Tesla Powerwall 3 from £6,350 installed, and the Duracell Dura16 at £4,450 installed when it is fitted alongside solar panels. Both use lithium iron phosphate cells, both carry ten year warranties, and both are fitted by an MCS-certified installation team for your area. Past that point they are genuinely different machines, and choosing between them comes down to three things: what you need powered in a cut, how hard the battery will be cycled, and what each stored kilowatt hour costs you.

Two different machines

The Powerwall 3 is a floor-standing tower that contains the entire system. Inside the one enclosure sit 13.5 kWh of usable storage and a full hybrid solar inverter that accepts up to 20 kW of solar DC across three maximum power point trackers. It delivers up to 11.04 kW, enough to run a whole house including showers and ovens, and its battery and power electronics are sealed to IP67, so it lives happily outside against a wall. On a new solar and battery installation it simply becomes the inverter: the panels wire straight into it and there is no separate box to buy.

The Duracell Dura16 LV takes the opposite approach. It is a wall-mounted low voltage battery, 51.2 V and 314 Ah, holding 16 kWh of which 14.4 kWh is usable. It charges and discharges at up to 130 A, which is 6.6 kW at its nominal voltage, in a fanless IP65 case weighing 122 kg. It has no inverter of its own, so it pairs with a compatible hybrid inverter sized to your solar array. It is manufactured and warranty supported by Puredrive Energy Limited in Gloucestershire, building under licence to the Duracell name.

Capacity and how each one scales

Out of the box the Dura16 actually holds more: 14.4 kWh usable against the Powerwall's 13.5 kWh. Either covers a typical home's evening and overnight comfortably, and our guide to what size home battery you need shows how to check that against your own consumption. The difference appears when you want more.

The Powerwall scales with Expansion units: 13.5 kWh slabs, DC coupled behind the main unit, up to three per Powerwall 3. Our package with one Expansion gives 27 kWh from £10,850 installed. The Dura16 scales by adding more of itself. Two units give 28.8 kWh at £8,900 installed alongside solar, and the datasheet supports up to twelve in parallel, although the hybrid inverter's charge rate, not the battery bank, becomes the practical limit long before that. For most homes the honest ceiling on either path is the second unit; beyond roughly 27 kWh you are storing more than a domestic array and tariff cycle can usefully fill each day.

Backup in a power cut

Grid-tied solar and battery equipment shuts down in a power cut by design, a safety behaviour called anti-islanding, so keeping the lights on always needs dedicated switching hardware. Here the two systems part company properly.

The Powerwall route is the Backup Gateway 2. It sits between the meter and the consumer unit, watches the grid, and on a failure disconnects the house and switches it onto the battery automatically. That is whole home backup: every circuit, at up to the full 11.04 kW, with the solar array still generating and recharging the battery while the grid is down. The Dura16 route is the emergency power supply function of its hybrid inverter, which typically feeds a single dedicated socket or a small sub-board of essential circuits such as the fridge, some lighting and the broadband router. Output in backup is capped by the inverter's EPS rating and by the battery's 6.6 kW, so it keeps essentials alive rather than running the house as normal.

If backup is your main reason for buying, the comparison is really Gateway versus EPS rather than Tesla versus Duracell. Our guide to whole home versus partial backup covers which tier of cover suits which household, including the medical equipment and home working cases.

Warranty and cycle life, with the arithmetic

Both warranties run ten years, and the small print measures different things. Tesla guarantees the Powerwall 3 will retain 80% of its original usable capacity at ten years in the UK, with unlimited cycles for self consumption, time of use charging and backup, and requires the unit to keep a reliable internet connection for firmware updates. Duracell's cover is capped at 8,000 cycles or 100 MWh of energy throughput, whichever arrives first, and no retained capacity figure is published.

Run the numbers on the Duracell caps before deciding they matter. One full cycle a day puts about 5.3 MWh a year through a Dura16, so ten years of daily cycling uses roughly 3,650 cycles and 53 MWh, comfortably inside both limits. The caps only start to bite under heavy tariff arbitrage: a household forcing two full cycles a day, charging cheap overnight at rates like 8p and again from midday solar, would cross 100 MWh just inside the ten year term. For normal solar-shifting use, both warranties run their full distance.

Price per usable kilowatt hour

Duracell package prices apply when the battery is fitted alongside solar panels. Powerwall figures are starting prices; both are subject to survey. Specifications from the manufacturers' datasheets.

The arithmetic behind that last row is short. £6,350 across 13.5 usable kilowatt hours is about £470 each; the 27 kWh Powerwall package from £10,850 improves that to about £402. The Dura16 at £4,450 alongside solar across 14.4 kWh comes to about £309, and two units at £8,900 on the same basis across 28.8 kWh hold the same £309. On storage per pound the Duracell wins at every size, by roughly a third against a single Powerwall. What the Powerwall premium buys is the integrated 20 kW solar inverter, whole home backup capability, 67% more power output, and a published capacity retention guarantee.

The condition on the Duracell price

The £4,450 figure is not a general Dura16 price; it is the price when the battery is installed alongside solar panels. The saving is real and structural: the hybrid inverter that runs the battery is the same unit running the panels, and the electrician, the scaffold visit and the DNO paperwork are already on site for the solar job. Fitted on its own, a Dura16 still needs an inverter and a full installation visit of its own, so battery-only pricing is a different quote and we confirm it on a design call rather than publishing a number that needs a page of caveats. The 0% VAT rate on domestic battery storage applies either way until 31 March 2027.

Which one fits your home

For the wider field beyond these two, our Powerwall 3 versus the alternatives guide sets the Tesla against the modular systems, and the full brand comparison covers the whole UK market datasheet by datasheet.