Almost every UK battery quote features one of these three brands. Here is how they differ once you strip out the marketing.
Tesla Powerwall
Around 13.5 kWh usable with high continuous power output, which makes it the strongest option if you want to run heavy loads or whole-home backup. Excellent app. Typically the most expensive per kWh, and availability through UK installers varies.
GivEnergy
UK-based, modular, and available in a wide range of sizes from about 2.6 kWh up to 9.5 kWh per unit which can be stacked. Strong value and a well-liked monitoring portal. Good fit for households sizing a battery precisely to their consumption.
Sunsynk
Usually paired with Sunsynk hybrid inverters, popular with installers for flexible system design and competitive pricing. Solid warranties, and a good option where you are installing solar and battery together from scratch.
What matters more than the brand
Usable capacity, not nominal. Compare the usable kWh figure. Round-trip efficiency of 88% or better. Warranty — ten years and a stated end-of-term capacity. Tariff compatibility — if you plan to charge cheaply overnight on an off-peak tariff, confirm the system supports timed charging.
Sizing rule of thumb
Most UK homes land between 5 kWh and 10 kWh. Oversizing wastes money because the extra capacity never cycles. Look at your overnight and evening consumption, not your total annual usage.
Get two or three battery quotes so you can compare usable capacity per pound, which is where the real differences show up.