Intermittent battery drain

[jmkgreen]

I have an 08 Focus 1.6 petrol that in the past few months has given me intermittent flat batteries which my local garage is puzzling over.

Back in November my wife had a stay in hospital which meant it went from being used weekdays to nothing. Within days, after a frozen night I was unable to move the car due to a flat battery. Fine, a couple of weeks later it was jump started and the battery replaced for good measure.

March - lockdown, start working from home. A short few weeks after this I have another flat battery. Fine, jump start, give it a good trip and all is well again.

Barely a month passes and two more flat batteries. Local garage gives the car a look over for faulty lights and other obvious reasons - nothing wrong found, perhaps a faulty battery from last November? Back I go and get a replacement battery under warranty.

Fast forward and I can't turn the engine over mid-week. There's a loud "clacking" noise under the passenger dash area even though this time the dashboard clock isn't asking to be set. The next day a friend arrives to jump start and by now it is back to asking for the date/time and the radio code. So something's apparently randomly draining the battery.

Local mechanic says the only thing he's aware of of these models is the dashboard instrument panel occasionally going wrong and draining batteries but it's a long shot. Suggests I ask on the internet in fact!

So here I am. Any thoughts? Or am I the owner of a car that really hates being left more than a few days without being driven..?

 

[ColW]

I currently have an issue with my mk3 2011 focus.

All through lockdown I used it on odd occasions to go to the shops maybe once or twice a week without issue.

It had a brand new Bosch battery just over 2 years ago so I don't think my issue is the battery.

Since going back to work I have no issues starting up in the morning and driving to work. It happens occasionally when I finish work and come to unlock the car and get nothing. No remote unlock or keyless entry and after opening the car manually nothing on the display. Luckily work have a jump starter battery pack so after connecting the pack I sometimes get the horn beep or just indicators flash. It starts up no problem then and is fine again the next morning after driving home.

I suspect a bad earth or battery terminal connection as it only happens when left at the office during the day. At weekend sat at home it is fine sometimes not used from Friday evening coming home until Monday morning going to work.

[mrmetallica]

1 hour ago, jmkgreen said:

I have an 08 Focus 1.6 petrol that in the past few months has given me intermittent flat batteries which my local garage is puzzling over.

Back in November my wife had a stay in hospital which meant it went from being used weekdays to nothing. Within days, after a frozen night I was unable to move the car due to a flat battery. Fine, a couple of weeks later it was jump started and the battery replaced for good measure.

March - lockdown, start working from home. A short few weeks after this I have another flat battery. Fine, jump start, give it a good trip and all is well again.

Barely a month passes and two more flat batteries. Local garage gives the car a look over for faulty lights and other obvious reasons - nothing wrong found, perhaps a faulty battery from last November? Back I go and get a replacement battery under warranty.

Fast forward and I can't turn the engine over mid-week. There's a loud "clacking" noise under the passenger dash area even though this time the dashboard clock isn't asking to be set. The next day a friend arrives to jump start and by now it is back to asking for the date/time and the radio code. So something's apparently randomly draining the battery.

Local mechanic says the only thing he's aware of of these models is the dashboard instrument panel occasionally going wrong and draining batteries but it's a long shot. Suggests I ask on the internet in fact!

So here I am. Any thoughts? Or am I the owner of a car that really hates being left more than a few days without being driven..?

 

how about unpluging the instrument panel see how it goes ?

 

[Luke4efc]

A failing bluetooth module can also cause the battery to go flat. This includes if you have an aftermarket head unit that won't utilise the factory bluetooth module. Maybe unplug that for a while and see how it goes.

[StephenFord]

Unfortunately a battery drain in a car is like a cough in a human - there can be 100s of different causes. Rather than taking it to your local garage, I would consider using an experienced auto electrician who will have the diagnostics tools, and more important, the experience to diagnose a parasitic  battery drain.

You'll get loads of well meaning posts telling you that when they had a battery drain, it was a faulty earth, or a faulty light switch, or a faulty radio, or a faulty bluetooth module etc etc which just proves that for them that was the cause of their fault, but not really properly diagnosing what your fault is!

[jmkgreen]

There's no bluetooth module and I have no idea how to disconnect the instrument panel - I'm hoping by the suggestion that it's a trivial 2 minute exercise that can be done daily..!

My local mechanic suggested auto electrician, then told me his reliable local one had disappeared. "Good luck finding one" he said...

Oh well!

[StephenFord]

14 minutes ago, jmkgreen said:

My local mechanic suggested auto electrician, ....

That's great advice, wish I'd have said that LOL

[jmkgreen]

Just now, StephenFord said:

That's great advice, wish I'd have said that LOL

Reiterating 🙂

I might just buy a jump start pack. May be less convenient at the time but also more versatile.