Hey all, first time posting here.

I have a 2013 model and it recently developed a problem.

About 2 weeks ago, I went to start my car in the morning and it would not start. The battery was very low/dead. I checked and I had not left anything on overnight.

Looked online and managed to do a parasitic drain test on the battery, showing that something was draining the battery when the car was off. So, following instructions I have pulled out fuse after fuse to see what makes the draw go down. Fuse 21, behind the passenger glove box was the culprit!

I have had this fuse unplugged for about a week now and everything has been fine. Until last night.

Went to start the car, dead. Multi meter showed 12.16V.

Charging it from the mains today, but I thought I had found the issue. Clearly not.

Could someone with a bit more know-how help me out at all?

My next step was to disconnect the negative over-night to see if it's the battery as well (which is still under warranty)

Thanks.

12.16V should still be enough to start the car.

How old is the battery? If it's the original battery I'd change it.

49 minutes ago, alexp999 said:

12.16V should still be enough to start the car.

How old is the battery? If it's the original battery I'd change it.

Hey thanks,

Yeah it's a new battery, still under warranty.

I was considering charging it today, taking off the negative and leaving it over night. Then taking a reading of the battery to prove if it's drain or the battery that is bust.

When you say the car is dead, is it electrically dead, so no dash displays, or just that it won't start? Do you hear any relays?

So it's not electrically dead, but when I turn the key the lights on the dash come on, but it won't start.

When I turn the key it does make a series of clicking noises, and when it's jumped from another car it starts up fine.

Hi Ross,

I have been experiencing the same issue, I bought a Bosch S4 063 battery for my Fiesta back in October 2021 and I have been experiencing parasitic battery drain. With a bit of fuse pulling in the internal fuse box, I isolated the drain from Fuse 20 and Fuse 21. The drain was considerably less on Fuse 20 (Multi-Functional Display/HVAC) and so I pushed it back in, plus I don't fancy driving around with no air-con and no blower. With Fuse 21 out, I have been driving for 2 months without the radio - but occasionally I still suffer from a failed battery too (car unlocks, dash lights come on, repetitive clicking and flashing when trying to start). Luckily I have my trusted NOCO GB40 to hand when the car decides to fail on me.

Got a mechanic to check my alternator and to replace the alternator belt - after spending £150 I don't fancy handing it back in for 'further testing'. My current battery size is 207x175x175 and some of the Diesel Fiesta Owners are rocking a larger battery 278x175x175. This is going to be my next solution as I have noticed a considerable gap in my battery tray. This of course does not solve the issue but because of the greater starting power and greater capacity - the problem might be a little less noticeable (especially in the colder months).

I have also considered a battery isolator switch/tap where you can disconnect the battery from the car preventing future draw. This is not ideal because you would have to unlock/lock your car using the key and open the bonnet before and after every use to 'turn off' the power.