Excessive Battery Drain

[SeaGrey]

I'm trying to work out if my car has a fault that's draining the battery excessively, or perhaps that the battery itself is knackered (car is a 2010 TDCi Titanium).

If I leave a SatNav plugged into the interior 12V socket to charge (unit turned off), should this cause the battery to go flat within a couple of days ?

The battery has gone flat a few times lately while parked, preventing the car from starting the next morning. There are no lights left on, it's double locked and alarmed etc..the only thing I can think of that's using power is the SatNav.

It was flat again this morning. I'd driven about 50 miles on Sunday, and my wife about 10 miles yesterday. The SatNav had been plugged in since Sunday.

I actually took the car to Halfords on Sunday after the 50 mile drive, for a battery diagnostic test, and they found nothing wrong with the battery and charging voltages. The only thing he noticed was that the overall battery voltage was low, which suggested it wasn't getting fully charged. He suggested our problem could be because we only do short journeys with the lights on etc.. but I replied saying that could represent almost all drivers ! Besides, 60 miles in 2 days isn't exactly short journeys, and my battery was dead this morning.

While the battery was flat, I checked it with a voltmeter. It read 8.5V with the car unlocked, door open. It read 9.0V with the doors locked and car alarmed. With the wiring disconnected from the battery it read 10.5V

So it's still on charge now - something I'm getting used to.

Anyone else had any similar experiences ?

Also - just curious to know - I always disconnect the wiring from the battery before charging it. Is this necessary ?

[artscot79]

not being funny but if youre leaving the sat nav constantly plugged in no wonder its going flat the 12v still works even when the cars off so it will be using constant power

[SeaGrey]

I know what you mean, it does just sound like I'm being a bit daft - but on previous cars we used to leave the same Garmin unit plugged in all the time without ever flatting the battery. In fact, this is the first car I've had (since my old RS Mexico) that has flatted the battery just while parked up overnight.

It could just be that I need to get used to more modern vehicles, i.e. maybe they use a bit more power when parked, i.e. ECU, alarm and any other electric gizmos that still draw some current.

So I'm just wondering if people find that their newer cars have more problems with batteries going dead, just through general, but perhaps slightly careless use, as in my case. I mean how much electricity can a SatNav drain while on charge ? Surely a car battery has the capacity to charge a thousand SatNavs ?

[wase16ll]

im often called out for jump starts when owners leave a mobile charging for a few hours...it does make a difference but it could also mean the battery is servicable, but weak.

can always do a current draw test with an amp meter...disconnect one of the terminals, connect the amp to terminal and post...check the current with all electrics off/doors closed etc, then plug the sat nav charger in and check again...compare the readings

[artscot79]

most older cars i had didnt have the 12v but the lighter socket but they were switched ignition meaning with the car off there was no power to them the ford isnt like that its constantly powered so it will just keep draining away even when the units charged

[Stoney871]

Safer to bring the satnav indoors and charge overnight.

[jeebowhite]

Amongst other things the satnav in the house is more likely to keep your windows intact and the local scavengers out of pocket...

[vince_13]

not sure if this happens with new batteries but when i had my first car and my battery died the AA told me that the battery had reached it saturation point, where the battery has become so low that any attempts to recharge where futile due to the battery not being able to recover the losses,

i myself took the battery to get tested and was tested ok, when engine running and when turned off, however the battery slowly drained over night, new battery was the cure, however in order to prevent the this occurring the original source to the draining would need solving

[jeebowhite]

IMHO a flat battery is fine but three times and you need a new one. seems after three flat lines as Vincent said, it's unrealistic to trust it and will play games soon enough

sent using the Ford OC app for android.

[FOCA]

As others have said, the sat nav is a constant drain - it does not use a lot of power, but its like a dripping tap - it builds up over time and slowly drains the battery all the time (on top of all the other battery drains - it could be the "feather that breaks the camels back")

With constant short journeys and the high (huge) electrical drain on modern cars, (just opening the door lighs up the interior like Blackpool iluminations- this is the critical time before the engine is started- )

8.5v is too low, if the voltage drops below 10.5v a fault code is generated - as you have mentioned, letting a lead acid (/silver-calcium) battery run low, knacks it - my own car does not start if it is below 11v, and normally stays above 12v with the engine not running, and upto (approx) 14v with the engine running

If you have the sat-nav switched from the ignition (only on when the ignition is on) and change all the interior bulbs to LEDs (typically 1/5th to 1/10th the power drain - makes a significant difference because this drains the battery before the engine is started) you might be able to carry on with your present battery, if you keep it charged.

A set of jump leads and a booster (always kept charged) kept in the car would keep you out of trouble/ give you peace of mind -

Realistically, though, with allowing it to get so low, you have probably knacked it and would probably be safer replacing it with a new battery to get you through the winter, and with the sat-nav and LED interior lights that will stop you "taking out" the new battery as well

Of course if its a smart-charge system it should be a silver-calcium battery

[alpinestomper]

Hi All - have just joined and am the proud owner of a 2011 2.0 diesel Mondeo Estate Powershift. - had to have the guy out

this morning to jump start me. Am wondering if I need a new battery or is it an issue with certain Ford cars?

[Stoney871]

I'd give the car a good run and then check the battery voltage.

When off the voltage should be about 12.4 volts and when running about 14.5 volts.

Diesels need a good long run to sustain the battery and the glowplug relay can really pull a worn battery down.

I recently changed my battery (about 4 years old) as it wasn't maintaining charge and the glowplugs were pulling it down to about 9 volts which was too low to crank the starter motor.

I was advised that if a diesel isn't given long runs on a regular basis to charge the battery every 3 months or so to keep it healthy.

A visit to a decent battery centre to test the battery and smart charge system would be prudent.

[artscot79]

My old battery would start the car but it was sluggish starting it didn't generate a low battery light as it was always just above the lower limit the difference after the battery was changed was like night and day sometimes the battery as in my case was just old 9 yrs old in fact

[SeaGrey]

Looking back to the problems I was having, I'm putting it down to a combination of slightly aging battery and lack of experience.

The first thing I did was 'realise' that modern cars do simply drain the battery more than older cars when parked. This surprised/annoyed me, but now I just live with it.

As advised here, I suspected that the battery was beyond its best having been flatted a few times, so bought a new Bosch S5 Silver, which wasn't cheap at £100, but straight away higher capacity than the original. Like Stoney871, the original battery was 4 years old when I replaced it with this new S5. I too had never seen any low battery lights, despite issues.

I then purchased a CTEK MXS 5.0 'smart' charger, and now when I go on holiday for, say, 2 weeks, I run the car's battery through a 'conditioning' cycle when I get back. I also run through this cycle every couple of months, as the car is mainly used for short journeys (my wife's daily commute). I now think a modern diesel like my Focus cannot simply rely on alternator battery charging alone when mainly driven in slow traffic each day.

With the CTEK MXS 5.0, my battery now consistently stays above 12.6/12.7V after being parked overnight, which is just about perfect in my view. As mentioned above, I think if it starts dipping to 12.4V it might be necessary to do more than simply driving the car to recharge the battery. It's too early to say yet, but I'm confident that an intelligent charger like the MXS 5.0 does improve the battery's lifespan and performance, so will pay for itself in, say, 10 years - and more if you have more than one car or battery (I also use it to top up a leisure battery I take camping to power the fridge).

Another little tip - I wanted to get a decent phone charger, and went with the an item by Capdase called the T2 charger/monitor which displays battery voltage. We leave this plugged in all the time so we can view the current battery voltage, which might seem daft considering what I've said before, but this charger has an insignificant drain on the battery (couldn't detect any difference in drain using an ammeter). I've compared its voltage readout using an expensive DVM on the battery, and it's spot on, hence I'm confident in saying my car battery is always around 12.6V when parked.

Oh, and one final point, when I spent time a year so back monitoring the battery at different times, I noticed that there are about 4 different levels of battery consumption when the car is parked :

1. engine is off, but main electrics still on (Power button pressed on without clutch pedal)
2. engine is off (Power button off) but car not locked/alarmed
3. engine is off and car locked/alarmed
4. same a 3. but after being left for about 20 minutes, i.e. sleep mode

There's a considerable difference in battery current drain comparing the above situations (can't remember exact figures now). So anything preventing the car reaching level 4. will drain battery excessively. Symptoms of it not going into sleep mode are the main LED dash board console staying on all the time, i.e. faulty boot closure sensor.

Good luck !

[Stoney871]

I have one of these now so I can monitor voltage variations-

http://pages.ebay.com/link/?nav=item.view&id=360650995916&alt=web

Even with a new battery when the glow plugs are energised it dips to about 10.8 volts but comes back to over 12 volts again when the plugs go off.

Modern cars are power greedy and often alternators are purely maintaining batteries but not necessarily providing enough to fully top up a low battery charge.

Add winter driving with lights, wipers, heaters, demisters and everything else into the mix and very soon there is not much left for the poor battery.

Top tip- carry a boost pack, it can really save your bacon.

[sonic113]

I have one of these now so I can monitor voltage variations-

http://pages.ebay.com/link/?nav=item.view&id=360650995916&alt=web

Even with a new battery when the glow plugs are energised it dips to about 10.8 volts but comes back to over 12 volts again when the plugs go off.

Modern cars are power greedy and often alternators are purely maintaining batteries but not necessarily providing enough to fully top up a low battery charge.

Add winter driving with lights, wipers, heaters, demisters and everything else into the mix and very soon there is not much left for the poor battery.

Top tip- carry a boost pack, it can really save your bacon.

Been thinking of picking one of those up. are they a good job?

Also been looking fro a booster pack but there is so many to choose from can anyone recommend a good one for decent money?

In regards to batteries how can you tell if your car has the "smart charge" system so if you ever needed to get a new battery you get the right type?

[Stoney871]

The voltage meter is simple but does the job.

Halfords do a few different boosters.

Mine was £35 (special offer and club card).

All current Fords are smart charge.

[Stoney871]

This is the one I have, cracking bit of kit-

http://www.halfords.com/webapp/wcs/stores/servlet/ProductMobileDisplay?catalogId=10151&langId=-1&categoryId=255204&productId=993469&storeId=10001

[sonic113]

The voltage meter is simple but does the job.

Halfords do a few different boosters.

Mine was £35 (special offer and club card).

All current Fords are smart charge.

Out of curiosity how what is smart charge and how does it work?

The link you sent regarding the booster looks like job. Does it take a while to charge it up and how often do you recommend taking it out of the boot to check or top up the charge I was thinking once a month maybe.

The usb on it looks like a bonus.

[Stoney871]

Smart charge is supposed to ensure correct power distribution to car functions while maintaining the battery, TBH all it seems to do is make us buy more expensive Silver Calcium batteries.

When I got my booster it was charged for 24 hours prior to going in the boot, you're supposed to top it up after every use and at least every 2-3 months.

I've used it 5 times on my car and others and it's still going strong.

[Stoney871]

It also has 2 12v sockers which are handy for inflatable camp beds and running tyre pumps/car vacs without trailing wires all through the car.

The LED light is not uber bright but is useful in emergencies.

[PamelaH]

I wonder if any auto-electricians out there have any ideas on this irritating problem I have had pretty well throughout the four-year life of my Fiesta ?

I have had a succession of battery failures, going either almost or completely flat, usually overnight for no obvious reason. Each time they checked, the AA proved there was a good output from the alternator and there was no current drain. The Ford dealer subsequently changed first the alternator and then the battery under warranty (although I am not convinced that the battery they fitted was a new one).

I eventually put the problem down to the frequent very short journeys I do and fitted an LED voltmeter plugged in to the power socket to monitor the battery voltage.

Usually, the voltmeter shows about 12.2 volts static and after start up and sometimes goes up to 14 v settling down to around 13.0 - 13.2 whilst driving. I have taken to putting it on trickle charge every few weeks which I think should not be necessary.

The battery failed again only last week which was quite inconvenient.

What has prompted this particular post is that while out yesterday, I noticed that the voltage dropped to only 11 volts with no lights or heated screen on which quite concerned me. To see how low it would drop with a load, I switched on both heated screens, half expecting the engine to cut out but to my surprise it actually rose to 13.2 and stayed there after I switched the screens off.

When I got home I kept the engine running and double checked the reading across the battery with my Fluke testmeter and it showed a normal 13.2 - 13,5v, confirming the LED reading inside the car.

The car has only done 17,000 miles in four years.

Anyone have any ideas ?

I'm trying to work out if my car has a fault that's draining the battery excessively, or perhaps that the battery itself is knackered (car is a 2010 TDCi Titanium). If I leave a SatNav plugged into the interior 12V socket to charge (unit turned off), should this cause the battery to go flat within a couple of days ? The battery has gone flat a few times lately while parked, preventing the car from starting the next morning. There are no lights left on, it's double locked and alarmed etc..the only thing I can think of that's using power is the SatNav. It was flat again this morning. I'd driven about 50 miles on Sunday, and my wife about 10 miles yesterday. The SatNav had been plugged in since Sunday. I actually took the car to Halfords on Sunday after the 50 mile drive, for a battery diagnostic test, and they found nothing wrong with the battery and charging voltages. The only thing he noticed was that the overall battery voltage was low, which suggested it wasn't getting fully charged. He suggested our problem could be because we only do short journeys with the lights on etc.. but I replied saying that could represent almost all drivers ! Besides, 60 miles in 2 days isn't exactly short journeys, and my battery was dead this morning. While the battery was flat, I checked it with a voltmeter. It read 8.5V with the car unlocked, door open. It read 9.0V with the doors locked and car alarmed. With the wiring disconnected from the battery it read 10.5V So it's still on charge now - something I'm getting used to. Anyone else had any similar experiences ? Also - just curious to know - I always disconnect the wiring from the battery before charging it. Is this necessary ?

[MONDEO TXS 2.2]

Parasitic drain ?