Sonnen - Battery Reviews

About Sonnen

Sonnen is a German brand that attracted quite a bit of attention in Australia, partly due to assembling batteries in South Australia at one point. Although that's no longer happening, the company still maintains an office here.

Australian Office Contact Details

Address: Lionsgate Business Park, Tenancy 6/180 Philip Hwy, Elizabeth South SA 5112
Telephone: 13 76 66
Email: support@sonnen.com.au
Australian website

Company Info

Founded in 2010, Sonnen GmBH was one of the first suppliers of lithium ion solar batteries for home use in Germany. These days, sonnen is 100% owned by Shell (Shell Overseas Investment B.V.).

In 2018, the company begun assembling batteries at the former Holden site in Adelaide's northern suburbs, kicking off with 50 full-time employees. While having very optimistic plans for production from the site, its operation was relatively short-lived. Sonnen ceased assembling batteries in South Australia in the middle of 2022. The company attributed the decision to rising costs and supply chain disruptions caused by the COVID-19 pandemic. Assembly then shifted back to Germany.

Sonnen's Home Batteries

Sonnen's two lines of batteries available in Australia are the sonnenBatterie Eco 9.53 and Evo, which are both suitable for home installations - but there are some significant differences between the two.

sonnenBatterie Eco 9.53

Sonnen's flagship product was sonnenBatterie Eco (yes, the weird caps situation is annoying), which translated simply means 'sun battery' - clever, huh? For some reason, things always sound cooler in German.

The sonnenBatterie Eco  9.53 is an all-in-one unit - sort of. It includes AC battery inverter built-in but requires a solar inverter. The unit can be AC coupled or DC Coupled with 3-phase hybrid variant.

This is an expandable system with various capacities available up to 15kWh nominal capacity, 13.5kWh of which is usable (same as Powerwall 2). The 9.53 has higher nominal power output (4.6kW) than its predecessor, the 9.43, which had a rather ordinary maximum 3.3kW. The chemistry used in Eco cells is lithium ferro phosphate (LFP/LiFePO4). 

The sonnenBatterie Eco  9.53 has an operating temperature range of -5 °C – +45°C, but note that derating may occur at temperatures above 35 °C. The upper end of the temperature range would be problematic in some of Australia's toastier areas, but bear in mind this battery is indoor-rated only - it can't be installed outside as is.

Optional extras for the Eco include sonnenProtect, which offers backup and black-start functionality.

sonnenBatterie Evo

Unveiled in early December 2021 and available in Australia since 2022, the sonnen Evo battery also features LFP cells. It offers 10 kilowatt-hours of usable storage and 5 kilowatts continuous power (7kW surge capacity). 

Aside from less usable capacity a bit of a power boost compared to Eco and a wider operating temperature range (-10 °C to +50 °C), other differences include the Evo can be installed outdoors (IP 56 rated) and it has built-in backup capabilities rather than it being an optional extra. You can also can charge the battery from solar when grid is down. Like the Eco, the Evo includes an AC battery inverter, but also requires a solar inverter.

The dimensions of the Evo are 710 mm x 1400 mm x 427 mm and its installed weight is a hefty 163.5 kg

Learn more about this home energy storage solution in our sonnenBatterie Evo review.

You can view more specifications and estimated pricing for both batteries on our battery comparison table.

SonnenFlat - No More

Sonnen battery owners in NSW, QLD (Energex region), SA, ACT, TAS and VIC used to have the option of joining sonnenFlat, which enabled them to receive a guaranteed annual allowance of electricity from the mains grid for a fixed monthly fee, with supply charge included. The SonnenFlat program in Australia wound up in June 2024.

Warranty Information

The company offers a 10-year full warranty, or 10,000 cycles, whichever comes first. During the warranty period, all components are covered: the inverter, all power electronics, the energy manager and the battery modules. It is also covered if you join a Virtual Power Plant (VPP). 

Sonnen warrants that during the warranty period the capacity of a sonnenBatterie will not fall below 80% of the nominal capacity.

Pricey Batteries, Reports Of Poor Support

Sonnen's batteries are expensive. For example, the Evo costs around the same as a Tesla Powerwall 2 (which also isn't cheap), but has around 25% less usable storage capacity.

At the prices Sonnen charges, its batteries (like many others) currently may not pay for themselves under realistic conditions for many households within the warranty period. A significant reduction in cost would certainly help Sonnen achieve its stated vision of a "world in which everyone is able to cover their energy needs with decentralised and clean energy sources".

Aside from that, some of Sonnen's claims from time to time we've found to have been a little optimistic. We've also had multiple reports of poor support and of difficulties in commissioning the batteries. 

If you're an Australian Sonnen owner, your opinion of your system would be valued by other readers of this page - please leave your rating and review.