Tesla Powerwall 3 vs the Mystery Battery

Two batteries. One difference.

Spot the difference. We install both. They store almost exactly the same amount of energy, both can grow later, and both are fitted by our own MCS certified team. One of them costs £2,000 less.

Call 01202 985 888Or send us your details

12 year battery warrantyUp to 15 kW hybrid inverter built in£2,000 less installed

See them side by side

Our 90 second film puts the Tesla Powerwall 3 and the Mystery Battery next to each other: storage, stacking, inverter, backup and warranty, then the difference that matters most.

Sound on for the full effect. Specifications from manufacturer data. Tesla and Powerwall are trademarks of Tesla, Inc.

The numbers, in full

£2,000 less than our installed price for a single Tesla Powerwall 3, comparing like-for-like single battery installations, October 2026. Prices can change, so we’ll always confirm yours in writing. Specifications are taken from each manufacturer’s published data. Tesla and Powerwall are trademarks of Tesla, Inc. DES Renewable Energy is not affiliated with Tesla.

So what is it?

We’re not naming it in our adverts just yet. Let us introduce you: give us a call and we’ll tell you all about it, send you the full specification sheet for both batteries, and show you exactly how the £2,000 difference is worked out.

It is an all-in-one unit: the battery and a hybrid inverter of up to 15 kW in one cabinet, so there is less to fit on the wall and less to go wrong. Start with 14.4 kWh and add batteries later, up to 86.4 kWh.

Let us introduce you: 01202 985 888

Built by a serious manufacturer

Not a start-up and not a white label. Here is the company behind the mystery battery, minus the name.

What’s in the box

An all-in-one battery and hybrid inverter. Everything below is from the manufacturer’s published data.

• 14.4 kWh battery13.68 kWh usable storage.
• Up to 15 kW hybrid inverterSized to your home and your solar array.
• All-in-one designClean, compact and quick to install.
• Scales to 86.4 kWhAdd batteries as your needs grow.
• 4 MPPTsSolar across several roof orientations.
• Up to 200% PV oversizingConnect a larger solar array than the inverter rating.
• 10 kW whole-home backupKeeps high-demand appliances running in a power cut.
• Intelligent load managementDesigned to work alongside EV chargers, heat pumps and other high-demand appliances.
• Advanced safety protectionIntelligent BMS, temperature monitoring, fire suppression and pressure-release protection.
• IP65 ratedSuitable for indoor or outdoor installation.
• Rated to -20°COptional battery heating for reliable cold-weather performance.
• Smart monitoringManage it from the app, with remote software updates.
• 12 year battery warrantyAnd 10 years on the inverter.

Still like the look of a Powerwall 3?

Our own Tesla Powerwall 3 installation in Wimborne. Nothing in the photo has been altered.

That’s fine. We install Tesla Powerwall 3 too, so we can quote for either and help you pick the one that suits your home.

Both are fitted by our own MCS certified team, never subcontracted, and both come with our aftercare. The difference is in the warranty, the built-in backup and the price, and we will show you the numbers for your home either way.

What happens next

1Let us introduce youCall or message us. We’ll introduce the battery, send both datasheets and confirm how the price is worked out.

2Site surveyA 2.5% holding deposit books a qualified engineer. Fully refundable, with no obligation to proceed.

3Written quoteAll payments and workmanship warranties are insured through IWA, who contact you directly.

4DNO approval, then installOur own MCS certified team. Dates and scaffolding confirmed with you.

One of our battery installations in progress.