Sonnen reports »record life« for batteries
Post date: 15/07/2021 - 08:00
German storage manufacturer Sonnen GmbH announced that batteries achieve a »significantly longer life« than previously thought. Under long-term test conditions now running for nearly eight years, a type of lithium iron phosphate (LFP) battery used in the Sonnen battery has already achieved more than 28,000 charging cycles, the company said: »It can still demonstrate 65 percent of its original capacity in the process and has not yet reached the end of its service life.«
Since there is little long-term data on the service life of batteries in electricity storage systems, Sonnen has been operating its own battery laboratory at its headquarters in Wildpoldsried for several years, where batteries from various manufacturers has been tested over long periods of time.
In such a the long-term test, the LFP battery cell was exposed to »significantly harsher conditions than would be usual for a power storage unit in a household.« It was fully charged and discharged several times a day. In everyday life, less than one complete charge and discharge per day is required - in Germany, a home storage system completes around 250 charging cycles per year, which is less than one percent of the cycles now measured in the laboratory.
Sonnen is also testing battery modules, consisting of more than 200 battery cells of the same type. Such a module has already reached more than 10,000 charging cycles, according to the company, and still had 83 percent of its initial capacity afterwards. »This is well above the guaranteed value of 80 percent,« says Sonnen GmbH: »A battery that can be charged and discharged 10,000 or 20,000 times can provide much more energy with the same amount of resources than less durable batteries.«