Hi @Effie,
Welcome to the Dyson Community!
It’s not possible for us to confirm an exact lifespan for any component, including the battery, as this will depend on how each individual machine is used, maintained and stored. But the Dyson warranty period is 2 years, and we’d expect the battery to last for at least that long.
If you own a Dyson Corrale™ straightener and need some help with it, you’ll be able to reach your local Dyson Customer Care team by visiting Dyson.com and clicking Support.
If a replacement is needed within or outside your 2-year Dyson warranty, they’ll be happy to discuss your options with you.
We’ll look forward to speaking with you!