Car battery draining

[stefmcd]

AA chap confirmed battery is good but measured a .9 amp drain. Even after a long drive, 24 hours later, it won't start and I need to jump it from a spare battery. Focus St, 2018 with 40k. Battery was bought last July. The issue has, I think, been camouflaged by a long daily drive. Any ideas? I've tried pulling most of the under bonnet fuses to see if the drain reduced, without success.

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[PhilipK]

How are you measuring the parasitic current? With a clamp meter or with a multimeter/ammmeter in series with the battery?

Have you tried removing ALL the fuses and seeing whether the current drain reduces? (If so, you could then reinstall them one-by-one to see which is the problematic circuit).

I know nothing about Focuses, but is there only one fuse box? (Many cars have fuses in more than one place).

[Franky Four Fingers]

How long did the AA chap leave it for when doing the drain checks?

[stefmcd]

How long did the AA chap leave it for when doing the drain checks?

He watched the battery climb to 20% power after he jumped it. Took about 10 minutes.

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[stefmcd]

How are you measuring the parasitic current? With a clamp meter or with a multimeter/ammmeter in series with the battery?

Have you tried removing ALL the fuses and seeing whether the current drain reduces? (If so, you could then reinstall them one-by-one to see which is the problematic circuit).

I know nothing about Focuses, but is there only one fuse box? (Many cars have fuses in more than one place).

Hi. Sorry, not 100% sure. Both my mechanic friend and the AA chap measured it. I'll ask my pal what he was using.

We only tried a couple of fuses from the under glove box fuse board, the entertainment unit and one other. Problem with this is having to wait for the power usage to settle after you open the car door.

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[pete-r]

Has it got an amplifier as part of an OEM stereo? I had the 2006 ST with the Sony system. It wasn't turning itself off with the ignition and was draining the battery.

[sish101]

Not sure the Focus has this level of specification but this was an interesting troubleshooting session from Dan.

I very much enjoy his content even if I don't understand some of it.

https://youtu.be/1MHXAwfAVhg

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[zelig]

Has it got an amplifier as part of an OEM stereo? I had the 2006 ST with the Sony system. It wasn't turning itself off with the ignition and was draining the battery.

I had this with the wife’s Skoda Fabia.

Intermittently powered up on its own when the car was parked, which was enough to drain the battery.

Changed the unit with same model bought from eBay & solved the problem.

z

[stefmcd]

Only Thursday evening, the battery was strong enough to operate the start stop tech. By mid-day today, not enough charge to start the car. Had to jump from a spare battery.

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[stefmcd]

Has it got an amplifier as part of an OEM stereo? I had the 2006 ST with the Sony system. It wasn't turning itself off with the ignition and was draining the battery.

It definitely doesn't have the upgraded sound system, but that doesn't mean it doesn't have a separate amp somewhere. I'll mention this to my friend, thanks.

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[stefmcd]

I had this with the wife’s Skoda Fabia.

Intermittently powered up on its own when the car was parked, which was enough to drain the battery.

Changed the unit with same model bought from eBay & solved the problem.

z

Ta. I think these units are v expensive, so I hope not.

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[stefmcd]

Not sure the Focus has this level of specification but this was an interesting troubleshooting session from Dan.

I very much enjoy his content even if I don't understand some of it.

https://youtu.be/1MHXAwfAVhg

Sent through the ether by diddling with radio waves

Thank you.

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[Franky Four Fingers]

He watched the battery climb to 20% power after he jumped it. Took about 10 minutes.

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So your battery is only 20% charged and he left it only 10 minutes to do the test?

[stefmcd]

So your battery is only 20% charged and he left it only 10 minutes to do the test?

That was his first check at the recharge rate. I'd say he waited another 10 mins then told me to switch off and back on, which I did. When that was successful, he told me to take it for a half hour drive and book it in to a garage for a proper check/diagnostic.

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[stefmcd]

How long did the AA chap leave it for when doing the drain checks?

My mechanic pal checked the same level of drain when my battery was nearly fully charged after a long journey.

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[lewie]

Could you pull any stereo fuses to see if that gives an indication of draw- I had this too on a Ka

[stefmcd]

How are you measuring the parasitic current? With a clamp meter or with a multimeter/ammmeter in series with the battery?

Have you tried removing ALL the fuses and seeing whether the current drain reduces? (If so, you could then reinstall them one-by-one to see which is the problematic circuit).

I know nothing about Focuses, but is there only one fuse box? (Many cars have fuses in more than one place).

My pal definitely used a multimeter. Not sure re the AA chap.

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[stefmcd]

Could you pull any stereo fuses to see if that gives an indication of draw- I had this too on a Ka

Thanks. Yes, I tried that with the entertainment console 15a fuse. No impact. Not sure if there's another fuse for the music/amp, will check.

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[dice]

Are there any electrical aftermarket mods done to the car? Would be worth listing them all. Its unlikely to be switched stuff (like a bulb modification) but I'm thinking along the lines of an aftermarket amp, or dash cam. This may help to at least provide initial areas to focus on (no pun intended).

[stefmcd]

Are there any electrical aftermarket mods done to the car? Would be worth listing them all. Its unlikely to be switched stuff (like a bulb modification) but I'm thinking along the lines of an aftermarket amp, or dash cam. This may help to at least provide initial areas to focus on (no pun intended).

Good point. Nothing added inside the car. I had a remap done about 2+ years ago.

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[Kingstepper]

Could it be due to poor insulation somewhere and there’s a leakage current (though 0.9A is quite high)?

[adrianw]

Could it be due to poor insulation somewhere and there’s a leakage current (though 0.9A is quite high)?

A one amp drain should be very easy to find, someone on here said earlier start pulling fuses

[Kingstepper]

A one amp drain should be very easy to find, someone on here said earlier start pulling fuses

Yes, would have thought it could be found quite easily.

[stefmcd]

Thanks for replies. I've pulled all the fuses from under the bonnet without success, though some have caps that I didn't want to chance removing.

The glove compartment ones are trickier as you have to have car door open which sends a big drain to battery anyway triggering all the car systems.

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[lewie]

Ideal you just need someone sat inside the car removing and replacing one by while while the other person the the draw

[Pitfitter]

Tape over the door switch?

[YCymro]

Thanks for replies. I've pulled all the fuses from under the bonnet without success, though some have caps that I didn't want to chance removing.

The glove compartment ones are trickier as you have to have car door open which sends a big drain to battery anyway triggering all the car systems.

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Switch the interior lights off before pulling fuses?

[Franky Four Fingers]

My mechanic pal checked the same level of drain when my battery was nearly fully charged after a long journey.

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Sorry im probably not explaining myself very well……how long did they leave the vehicle for when it was reading 0.9 amps? Was it still reading 0.90 amps after 10 minutes or did they leave it 30 minutes plus?

[Weirdfish]

Have you actually thought the battery could be down a cell, or two, I'm of the belief that once a battery goes flat it's never going to be 100% anyway.
Batteries normally come with at least a 12 month warranty, any chance you could take it back?

[stefmcd]

Sorry im probably not explaining myself very well……how long did they leave the vehicle for when it was reading 0.9 amps? Was it still reading 0.90 amps after 10 minutes or did they leave it 30 minutes plus?

Probably 20/25 minutes.

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[stefmcd]

Have you actually thought the battery could be down a cell, or two, I'm of the belief that once a battery goes flat it's never going to be 100% anyway.
Batteries normally come with at least a 12 month warranty, any chance you could take it back?

Possibly, but the AA chap assured me battery was fine with his gizmo/multimeter. They usually want to sell you a new one so I'm assuming he was right.

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[stefmcd]

Ideal you just need someone sat inside the car removing and replacing one by while while the other person the the draw

My mate struggled to do that. I think they're very low down.

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[Franky Four Fingers]

Probably 20/25 minutes.

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I would just check that 20-25 minutes is long enough. I have no idea how long Fords take but certainly for a lot of cars its no where near long enough.

[Chris_in_the_UK]

I would just check that 20-25 minutes is long enough. I have no idea how long Fords take but certainly for a lot of cars it's no where near long enough.

I had a Honda CRV a few years ago that the 'AA man' came out to when it mysteriously flattened the battery overnight - after 15 mins he said that there was a parasitic drain somewhere. Honda dealer told me that some of the systems remain powered up to 45 mins after the engine is turned off.

[Franky Four Fingers]

I had a Honda CRV a few years ago that the 'AA man' came out to when it mysteriously flattened the battery overnight - after 15 mins he said that there was a parasitic drain somewhere. Honda dealer told me that some of the systems remain powered up to 45 mins after the engine is turned off.

Yes absolutely Chris, if its a car we’re not that au fait with we generally leave them an hour.

[magpie215]

I've had a failing/failed alternator diode cause a drain....worth checking.

[stefmcd]

I've had a failing/failed alternator diode cause a drain....worth checking.

I've had that mentioned before, thanks.

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[stefmcd]

Yes absolutely Chris, if its a car we’re not that au fait with we generally leave them an hour.

Are you suggesting it's just reading normally but the battery itself is gubbed and losing charge? That would be best case scenario, as the battery is still under warranty.

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[adrianw]

OP has anyone been over it with a Power probe

I’m assuming someone has unplugged the alternator to eliminate that as a lump, as the ECU

[Franky Four Fingers]

Are you suggesting it's just reading normally but the battery itself is gubbed and losing charge?

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Well kind of yes. I don't know how long your particular Ford takes to “go to sleep” but id say that 20 minutes probably wasn't long enough. If we’re talking JLR products it can take over 40 minutes to go down to an acceptable level which is around 20-30 milliamps.
Before chasing your tail trying to find a non existent quiescent drain i would contact Ford or a specialist and double check how long it takes your model to go to sleep. Id also check your battery tester as quite a few of these newer digital testers are as useful as tits on a nun, they don't properly load the battery, what’s needed is a good old fashioned drop tester.

[stefmcd]

Well kind of yes. I don't know how long your particular Ford takes to “go to sleep� but id say that 20 minutes probably wasn't long enough. If we’re talking JLR products it can take over 40 minutes to go down to an acceptable level which is around 20-30 milliamps.
Before chasing your tail trying to find a non existent quiescent drain i would contact Ford or a specialist and double check how long it takes your model to go to sleep. Id also check your battery tester as quite a few of these newer digital testers are as useful as tits on a nun, they don't properly load the battery, what’s needed is a good old fashioned drop tester.

Thanks. I see your point and, as you say, it could be a pointless exercise.

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[Liner33]

OP has anyone been over it with a Power probe

I’m assuming someone has unplugged the alternator to eliminate that as a lump, as the ECU

If OP had checked the car over properly they would have a solution by now, all i read is that a few people that have looked at it have limited knowledge.

It needs someone who can actually test it properly, best to contact a proper auto electrician if you cant find anyone else locally

[stefmcd]

If OP had checked the car over properly they would have a solution by now, all i read is that a few people that have looked at it have limited knowledge.

It needs someone who can actually test it properly, best to contact a proper auto electrician if you cant find anyone else locally

Was meant to be looked at by auto-electrician today, but he's let me down.



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[dice]

What type of battery do you have in the car, right now (since July 2018)? A pic would be ideal but if you know at least the make and model we can eliminate that.

I'm reading the 2018 Focus ST uses EFB batteries, which is a surprise as I thought they were inferior to the AGM type. In theory you can replace an EFB with an AGM, but not the other way around. With that in mind you should be fine regardless, but it would be handy to know at this point.

[Enoch]

My wife’s Jeep Grand Cherokee had a battery drain that would flatten the battery after 3 days. Auto electrician found an old tracker unit behind a panel in the boot. The tracker back up battery was long gone so it was taking all its power from the car battery. Also a slight draw on the siren for the alarm which didn’t even work, so that was chopped out as well.

[stefmcd]

What type of battery do you have in the car, right now (since July 2018)? A pic would be ideal but if you know at least the make and model we can eliminate that.

I'm reading the 2018 Focus ST uses EFB batteries, which is a surprise as I thought they were inferior to the AGM type. In theory you can replace an EFB with an AGM, but not the other way around. With that in mind you should be fine regardless, but it would be handy to know at this point.

Hi, I'm 90% sure it's efb. (I'm not near car now) It's a cheapo (£120 roll eyes) lion model w. Start stop, bought last July.

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[stefmcd]

My wife’s Jeep Grand Cherokee had a battery drain that would flatten the battery after 3 days. Auto electrician found an old tracker unit behind a panel in the boot. The tracker back up battery was long gone so it was taking all its power from the car battery. Also a slight draw on the siren for the alarm which didn’t even work, so that was chopped out as well.

Thanks. I'll keep that in mind when I get a pro to look at it.

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[Chris_in_the_UK]

Hi, I'm 90% sure it's efb. (I'm not near car now) It's a cheapo (£120 roll eyes) lion model w. Start stop, bought last July.

I had a decent spec Yuasa battery suddenly die at the end of it's 2 year warranty - symptoms were similar to yours (albeit on a LR Defender) and would not turn the engine over after a couple of days. Checked the alternator output, voltage under load, earth straps etc. Chucked a new Varta battery in, been fine ever since.

Cheap batteries are a false economy - always let you down when you least need it!.

[dice]

I'm no sparky, the drain makes it sound like its not solely a battery issue but I've been wrong before. The battery quality doesn't sound inspiring!

If you're paying for the electrician for their diagnostic time, depending on the cost I'd consider replacing the battery as an initial quick step. Best case it fixes your problem, worst case its one thing the electrician can discount as an issue. At 4 years and of "ok" quality, sounds like it might be about time anyway.

If you do end up buying one, don't go to Halfrauds or any big-name retailer. The markup is insane. Eg RAC are selling the Bosch EFB100 for £210...Tayna Batteries have it for £125 delivered next day (I'm not affiliated, just used them myself and recommended to mates, my go-to now). Please confirm thats the right one for your car though, I did a 1 minute Google its not a 100% confident recommendation!

[Chris_in_the_UK]

^^^^

Tanya is the place to go for batteries.