What is causing my intermittent battery draining fault on my ford fiesta 1.6 tdci?

Hi, I'm currently getting an intermittent fault on my ford fiesta 1.6 tdci (61 plate) the battery seems to drain fairly frequently, following online advice I have turned my Bluetooth off for the past month or so which so to speak stopped my car battery draining however it died on me and wouldn t turn the car over yesterday after work, previously my car battery has died multiple times in a week and needs to be left on charge over night to secure peace of mind, is this a known fault? I have read online that a software update might fix it? The car is in frequent use at least an hour of driving every day minimum

Take it to auto zone or ORielys and have them do a battery/alternator/starter diagnosis.

You need to test the alternator and the battery with a cheap multimeter. My bet is one of them is faulty. Probably the battery. There are tutorials online as are cheap multimeters.

Remove the light bulbs [if any] from inside your trunk engine bay and glove box. These are things you can't see but often cause batteries to go flat if they don't turn off like they're supposed to. If the problem stops then you will have significantly reduced the number of possibilities.

One thing to consider is the life of the battery. If that's the original one it's doubtless on its last legs, it's quite rare these days to get more than a few years out of one, especially with a diesel. A good battery place will test it properly. If it's on the way out replace it and then see how it goes. If you're still getting a drain a vehicle electrician can track the problem down for you.