According to information on the retailer's site, the lights are suitable for outdoor use.
"Set the mood for the Christmas season with our festive LED string lights that will look stunning in your backyard!" reads a product statement.
Since sharing her grim warning, Ms Denduck's post has received more than 1,800 reactions and hundreds of comments from people concerned about experiencing a similar problem.
"My husband's just gone to take ours down," wrote one person. "I don't know if it's the same type but they are from Kmart so not risking it."
While another added: "This is so concerning! Glad I don't have any of them, but not so good for the thousands of people that do!"
One person on the thread said they thought the problem may have been caused by the battery exploding due to the heat rather than a product fault.
"It is possible to get faulty batteries," said one. "Heat or not batteries can explode. Not necessarily a consumer recall needed [as] it could just be a one-off."
The lights from Kmart bought by Ms Denduck come with three rechargeable 12V batteries.
A Kmart spokesperson said the retailer had reached out to the customer to offer support as part of a commitment to ensuring all product are "fully compliant with regulations and safety standards'.
"At Kmart Australia safety is our number one priority and we are committed to ensuring the products we sell are fully compliant with regulations and safety standards,' the spokesperson said.