August 12, 2021: Around 10,000 residential storage system lithium batteries by LG Chem subsidiary LG Energy Solutions have been recalled because of a fire hazard, the US Consumer Product Safety Commission announced on August 4.
The RESU 10 (Type-R) batteries were recalled after warnings were issued that they ‘can overheat, posing a risk of fire and emission of harmful smoke’.
Five reports were received of the wall-mounted batteries, which store energy generated by solar panels, causing property damage and one injury, the CPSC said.
The batteries were made in LG Chem’s factory in Nanjing, China, between 2017 and 2018, according to Korean media, which said the recall had caused the firm’s stock price to drop by 6.7%.
In December 2020, around 1,815 units of the same model were recalled for the same reason, the CPSC having received five reports of fires resulting in minor property damage, but no injuries.
The latest recall came just two days after a four-day lithium battery fire was put out at a utility-scale Tesla battery site in the Australian state of Victoria.
International media reported that a 13-tonne lithium battery caught fire inside a shipping container and could easily have spread to other battery containers, but was kept under control and then finally put out.
The ‘Victoria Big Battery’ was installed by French energy firm Neoen when it was the largest grid-connected energy storage system in the world at 100MW/129MWh.
Tesla owner Elon Musk famously offered to waive the installation fee if it could not be completed within 100 days — and it was. It was doubled in size in September 2020.
Lithium battery fires are notoriously difficult to extinguish safely because they react with water, even when they are not alight.
“Statistically it’s not if they fail, but when,” says George Brilmyer, CTO at HighWater Innovations and formerly R&D manager of separator firm Microporous.
“It’s a million to one chance that a cell will fail but if you have tens of thousands of them on a cargo of containers, the statistics are against you that one is going to fail. With thermal runaway it’s then a cascading process as one by one ignites, and that’s why it takes days to put them out.”
The batteries have to be soaked in water for long enough to make sure that the water gets right into the cells, otherwise they can reignite.
Brilmyer believes the economic case for deploying lithium in containers is flawed. “You’re not moving them around, they are staying in a container on the ground, there’s no reason why you should be using lead at a fifth of the cost.
“Parts of Australia are very warm, so lithium cells will probably need air conditioning on to keep them cool — well if you do the energy balance and take that into account it doesn’t add up.”