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Battery Drain Problem


JPorter
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Hi Everyone!

I'm new here and in desperate need of help.

Let me explain the story and hopefully one of you have had this problem or will be able to assist me.

I went away last Saturday for a week in Spain, I flew from Gatwick and left my Ford Focus 2010 Zetec, 1.6 Diesel in the long stay car park.

I've had this car since March 2018 and had no problems with it what so ever.

Usually I drive this car every single day without fail and it will do around 70 miles every day it's driven. Sometimes less (40-50), sometimes more (100+). So it's never been sat for this long since I've had it! I brought it on 52,000 miles and now I'm on 64,000 I think!

So, after a week at Gatwick, when I returned to it, I found that I could not unlock it with the key fob only the drivers door while putting the key in the door. This only unlocked the drivers door and not the rest of the car, as due to the battery being dead the central locking didn't work. When I turned the key, there was nothing but clicking coming from under the glove box! No lights on the dashboard no nothing. I tried bump starting it, but it wouldn't come to life at all. It wasn't until I found a guy with some jump leads that we could get the car going again and I did the 100 mile drive back home which it had done previously to being left at Gatwick the previous week. The car had no problems at all on the drive home and I have used it all day today with no problems.

I've looked online and can't really find anyone with the same problem! The only one I've seen is that the glove box light stays on. However, I started recording a video on my phone, put it in the glove box and the light goes off as it should when the glove box door is closed. The light also isn't hot so it can't of been on!

I took it to Halfords today to see if it's just a problem with my battery. They could not test the battery as their equipment was showing something was draining the battery. However everything was off! Nothing was plugged into the cigarette lighters, interior light was off, key was in my hand. So, I could not get a reading from that. He then advised me that something is draining the battery and because it doesn't get left for a week, it's never caused me a problem. Now it has and it's bothering me as I'm going away for 2 weeks to Australia in December and don't particularly want to come back to a flat battery!

My car has a sub woofer fitted which runs a wire straight from the battery to the sub but has an amp wire going to the stereo (the stereo isn't factory) so the sub switches off when the car turns off we also tested this at Halfords that it wasn't the sub by removing the fuse from the subs power cable as it has an inline fuse. I also have a dash cam that I have connected to the fuse box so that it also switches off when I turn the car off and take my key out the ignition. The Halfords technician said that since the dash cam is in a fuse and connected to the ignition it wouldn't be the problem.

Other than that, the car is standard and I haven't ever spliced any wires or messed with the factory wiring or anything else in the car for that matter.

Can anyone help me diagnose this? Has anyone had this problem before?

Any help is greatly appreciated.  

Many thanks,

Joshua

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3 hours ago, JPorter said:

something was draining the battery. However everything was off!

It can be a real pig locating the cause of battery drain these days. The problem is so many bits are inter-connected by the CAN busses. A typical problem is that a radio or or other after-market equipment is not entirely shutting down. But the drain is not in that equipment. Instead it is connected to a CAN bus, and is keeping some other bit of the car awake, often the ECU. And the ECU does consume quite a lot of power.

One symptom is the backlight on the dash LCD stays on all the time, or for much too long. It usually shuts off after less than 30 minutes. This LCD, or the dash itself, do not consume much power, not enough to flatten a 40 to 80 AH battery in a week if the battery is in good nick, but are an indicator of unwanted CAN bus activity.

Often the only answer is to disconnect entirely (not just remove fuses) all non-essential equipment, and either do a long term drain test measuring the drop in battery voltage, or measure the current drawn from the battery with a meter. This is not dead easy, as high current spikes due to door locking & unlocking (for instance) can blow fuses on multimeters connected on a low enough current range to measure long term drain. But it can be done. The Ford radio socket has CAN bus connections in it.

As a guide, over a week it takes about 0.2A (200mA) to flatten a fully charged 40AH battery, or a 80AH battery that is a bit old and has about 50% capacity remaining. (168 hours times 0.2A = 33.6AH).

I frequently leave my car standing for 6 days, and it has never lost charge by that, so battery drain is not normal or inevitable. But if you use a car often, it can mask a dodgy battery that can still start a car, but has high internal leakage or greatly reduced reserve capacity. So a thorough battery test (avoid Halfords!) is a good idea. Internal leakage can not be tested by a quick test with some fancy gizmo, also avoid anyone who claims it can!

 

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14 hours ago, Tdci-Peter said:

It can be a real pig locating the cause of battery drain these days. The problem is so many bits are inter-connected by the CAN busses. A typical problem is that a radio or or other after-market equipment is not entirely shutting down. But the drain is not in that equipment. Instead it is connected to a CAN bus, and is keeping some other bit of the car awake, often the ECU. And the ECU does consume quite a lot of power.

One symptom is the backlight on the dash LCD stays on all the time, or for much too long. It usually shuts off after less than 30 minutes. This LCD, or the dash itself, do not consume much power, not enough to flatten a 40 to 80 AH battery in a week if the battery is in good nick, but are an indicator of unwanted CAN bus activity.

Often the only answer is to disconnect entirely (not just remove fuses) all non-essential equipment, and either do a long term drain test measuring the drop in battery voltage, or measure the current drawn from the battery with a meter. This is not dead easy, as high current spikes due to door locking & unlocking (for instance) can blow fuses on multimeters connected on a low enough current range to measure long term drain. But it can be done. The Ford radio socket has CAN bus connections in it.

As a guide, over a week it takes about 0.2A (200mA) to flatten a fully charged 40AH battery, or a 80AH battery that is a bit old and has about 50% capacity remaining. (168 hours times 0.2A = 33.6AH).

I frequently leave my car standing for 6 days, and it has never lost charge by that, so battery drain is not normal or inevitable. But if you use a car often, it can mask a dodgy battery that can still start a car, but has high internal leakage or greatly reduced reserve capacity. So a thorough battery test (avoid Halfords!) is a good idea. Internal leakage can not be tested by a quick test with some fancy gizmo, also avoid anyone who claims it can!

 

Where would you suggest getting my battery tested?

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3 hours ago, JPorter said:

Where would you suggest getting my battery tested?

If the battery is more than about 7 years old, then it may be worth having it replaced anyway. But then you would have to be more careful about battery drain. Going flat shortens a battery's life, it would be a shame to do that to a nice new one!

If you have a local garage you use for servicing, and that seems trustworthy, I would go there first. If they can't do it, they may be able to recommend a reliable auto electrician or other technician. It has to be by recommendation really. With electrical testing, so often someone buys a complex bit of kit, and sets up as an "expert", when in reality they know rather little, apart from pressing the start button on their bit of kit. Halfords staff usually fall into that category, and really only want to sell you a new battery.

As the car starts ok, and Halfords have claimed they have detected a current draw, I suspect the battery is ok, but it does need to be eliminated. Reserve capacity and internal leakage take longer to detect than starting current capability. A few hours with a known load (some lights left on) can test capacity, but at least 24 hours with no load (so not connected to the car if a drain is suspected) would be needed to even partly test for internal leakage.

But if a parasitic draw is seen, then it may need someone with experience and knowledge of modern electronic cars to isolate the fault. But unplugging the radio, and any bluetooth, sat nav or similar electronic devices is a good starting point.

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On 10/8/2018 at 6:34 PM, Tdci-Peter said:

If the battery is more than about 7 years old, then it may be worth having it replaced anyway. But then you would have to be more careful about battery drain. Going flat shortens a battery's life, it would be a shame to do that to a nice new one!

If you have a local garage you use for servicing, and that seems trustworthy, I would go there first. If they can't do it, they may be able to recommend a reliable auto electrician or other technician. It has to be by recommendation really. With electrical testing, so often someone buys a complex bit of kit, and sets up as an "expert", when in reality they know rather little, apart from pressing the start button on their bit of kit. Halfords staff usually fall into that category, and really only want to sell you a new battery.

As the car starts ok, and Halfords have claimed they have detected a current draw, I suspect the battery is ok, but it does need to be eliminated. Reserve capacity and internal leakage take longer to detect than starting current capability. A few hours with a known load (some lights left on) can test capacity, but at least 24 hours with no load (so not connected to the car if a drain is suspected) would be needed to even partly test for internal leakage.

But if a parasitic draw is seen, then it may need someone with experience and knowledge of modern electronic cars to isolate the fault. But unplugging the radio, and any bluetooth, sat nav or similar electronic devices is a good starting point.

Hi,

After handing my car over to an auto electrician today, he’s come back and said there’s nothing wrong.

He even showed me a video of it plugged in etc.

He advised due to it being parked at the airport it may of been my alarm going off constantly that made the battery drain.

So I guess my next test is when I next go away.. Will invest in a battery pack and park as far away from the runway in the car park as possible!

Very strange how he found nothing, I can only assume it’s the alarm!

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