For the third time I've had the battery give up on me.It seems to just 'die' completely overnight without warning. Previous time it happened, about a month ago, I took it into Ford dealer as it is still under warranty (just) and they simply charged it (which I had already done) and said it was down to my short journeys. It failed again yesterday morning - I had been on a longish run the day before (in the daylight) even the dash lights wouldn't stay on ! I called the AA under homestart cover and they checked it out and got it going and said all seems to be ok but I suspect the battery isn't holding it's charge. It had gone down to 11 volts overnight so that can't be right in my reckoning. The 3 yr warranty runs out this month so I am hoping I can make them replace it under warranty. Is 3 yrs a reasonable life for a battery ?

Well the battery failed on my Dad's Kia after 2 years and was replaced under warranty.

The average life is probably about 4-5 years but not overly surprising it has failed at 3. Also if it dies completely then even with charging it probably is damaged and will never hold a full charge again.

Just an update. Took the car into the Ford dealer with the AA report of duff battery and they kept it overnight and changed the alternator ! (under warranty). I wasn't convinced that this was the answer and a week later it happened again ! Called AA again, "yes you have a duff battery sir - third call out with the same fault will be chargeable" they said. Back to Ford again and they finally changed the battery (under warranty), keeping the car overnight again . They seemed to make it hard for themselves as changing the battery is a lot easier than changing the alternator ! Fingers crossed it'll be ok now. I could have told them that the alternator output was ok as I checked it myself. What sort of mechanics do these garages employ ?

I think in some cases they employ monkeys. Not only would it have been simpler to change the battery, it would have been far, far cheaper.

They're not mechanics anymore.

They just replace parts as instructed.

A true mechanic fixes things.

mechanics (sorry technicians) rely to much on plug in machines nowadays and all the old fault finding skills are being lost, i bet half of them nowadays have never heard of a drop tester.

I think in some cases they employ monkeys. Not only would it have been simpler to change the battery, it would have been far, far cheaper.

Dead right ! I could have changed the battery myself in a matter of minutes but as the car was still just under warranty... Took them two days to do it !

mechanics (sorry technicians) rely to much on plug in machines nowadays and all the old fault finding skills are being lost, i bet half of them nowadays have never heard of a drop tester.

Yes - they just keep changing parts until the problem goes away.

i had this problem on one of my old cars. if i did not use it over the weekend it would be dead by monday. i found it it was the alarm siren so i just disconnected it and it was fine after that. so my guess is that there is nothing wrong with the battery but something is using power when it shouldn't be. also had an audi have the fan keep coming on till the battery died and that was down to the fuse box getting full of water and damaging a relay

The big problem with these cars is the protected key fob which controls a host of systems related to thief protection. It’s my intent to have this shut off if I have crazy shutdown issues again. According to these clowns the key fob with problems cost 175 for the key alone then you must have it programmed. The old adage if it’s not broke don’t fix it. Just give me a key and stop this silly electrical system security crap. 

Damn right.  The modern world is filled with "solutions" for which there were never problems in the first place.

If they've replaced the battery with a similar one to what they took out, I suspect you'll be doing it again soon. The FoMoCo batteries they put in from the factory are terrible, and I've just replaced mine with a Yuasa.

Its crazy that your voltage dropped to 11 and the mechanics didn't suspect an issue with the battery. That's clearly got a dead cell or two. But hey, at least you got something out of the warranty before it ran out - that's a win I reckon.