This is a warning for all those who use defibrillators.

Your battery may not last as long as what was first thought.

Saint Jude Medical says the lithium batteries in nearly 350,000 implanted defibrillators may not give the patient proper warning that the battery is running low.

The medical device company based in Little Canada, Minnesota says patients will normally get a vibrating alert three months before the battery runs out.

But some batteries are running out close to 24 hours after the alert, leaving patients in a potentially life threatening situation.

Patients who have ICD and CRTD devices produced before May 23rd 2015 should contact their doctors and have their device checked.

If your doctor recommends replacing the device, Saint Jude says they will do it free of charge.