The firm said it had identified a battery issue but did not elaborate.
But if a lithium-ion battery cell charges too quickly or a tiny manufacturing error slips through the net it can result in a short circuit - which can lead to fire.
One expert urged the industry to find safer alternatives to lithium.
"I think one should be concerned and push towards safer battery tech," said energy storage expert Professor Clare Grey from Cambridge University.
"That should be an important focus on research and industry development.
