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battery not charging but no light


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Drove home today as usual. Later went to start the car and it barely turned over. The battery light never lit up but shows before you turn the starter. The battery resting voltage is 12.07 and when the engine is running is 11.7 but the battery light stays off. Any ideas welcome please. Alternator belt ok and the connections feel secure. Noticed btw that the starter motor felt quite hot though I had just driven 15 miles .

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OP you've touched on 3 places to start, battery, alternator and starter. I'd rule out the starter as that wont/shouldnt drain the battery. Am thinking charging should be higher but your manual should say what. Go to a local motor factors and get them to put the battery tester across the poles, should do it for free. Has the bulb been removed by some unscupulous person ?

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About 4 yrs old - it is lead acid though and Haynes states that a battery for this vehicle should be Calcium Silver. The battery has worked well for the past 14 months (it was originally bought for a Rover Metro now long gone due to rust). The Ka came with a Ca battery fitted but on putting that back in the voltages look the same - although the interior light does brighten up a bit when I rev the engine now - fingers crossed!

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1 minute ago, Jimpster said:

OP you've touched on 3 places to start, battery, alternator and starter. I'd rule out the starter as that wont/shouldnt drain the battery. Am thinking charging should be higher but your manual should say what. Go to a local motor factors and get them to put the battery tester across the poles, should do it for free. Has the bulb been removed by some unscupulous person ?

I agree - a test would be good. The bulb does light up when I switch on but goes out when I start the engine so it should be charging but isn't - it could be that the old lead acid battery I fitted has been fried by the smart charging system...

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If a Ca/Ag battery is specified, then the charging volts from the alternator are higher than for a lead acid, so may well cook the lead over a period of time.  On an old Ford, the initial excitation for the alternator is supplied through the ignition light, but I have no idea how it may be done on a Ka.

 

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I would say that your battery has a dead cell. It is putting quite a load on the alternator which is trying to charge the battery to at least 12.60V but is not going to make it.

The original Calcium Silver batteries are discontinued in favor of poorer quality versions that only last a third as long.

If you remove the charge control plug from the alternator (only for test purposes) then the charging voltage should be 13.6V. I would recommend getting the battery tested (Halfords will do it for free) and replace it if fails.

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Just checked again and the car is not charging the battery as the voltage never gets high enough. I checked my other car - a 1999 Suzuki Alto and that is 12.6v switched off and 13.8v when running - lead acid battery and conventional alternator.

Are the brushes on my Ka's alternator changeable in-situ please? Also, if someone has a circa 2006/7 Ka with the 1.3 Duratec engine and the same alternator as mine - with the 3-pin plug at the front, if you could please measure your battery voltage both switched off and with engine idling I could compare those with mine - it may be that the charging system makes things look problematic when they aren't - thanks.

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Have you disconnected the charge control plug from the alternator ?

No you can't replace the brushes on your 3 phase alternator, it doesn't have any.

Have you had the battery load tested ?

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15 minutes ago, unofix said:

Have you disconnected the charge control plug from the alternator ?

No you can't replace the brushes on your 3 phase alternator, it doesn't have any.

Have you had the battery load tested ?

Not yet re the load test.

I did disconnect the plug and the charging voltage did rise to the upper 12v range. The battery lamp took about 30 seconds to illuminate - no doubt computer monitored/controlled.

No brushes? I thought that a normal alternator had brushes that supply the armature winding and by varying the voltage to that winding you could vary the induced voltage into the three phase stator windings - hence the diode pack and regulator. Perhaps my knowledge is out of date regarding these later types.

I have refitted the original Ca battery that came with the car and went on a short journey - the voltage of the battery has stayed steady so perhaps all is ok and I'm just overthinking a dud lead acid battery - will update soon.

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5 hours ago, Oriskany said:

Perhaps my knowledge is out of date regarding these later types.

Yes technology moves fast. No brushes, last used around the mid 1990's I believe.

I think you will find as i previously said that one of the cells in the battery is dead.

Just for info purposes here is a link to how brushless car alternators work:

https://speedalternators.com/brushless-alternator

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18 hours ago, unofix said:

Yes technology moves fast. No brushes, last used around the mid 1990's I believe.

I think you will find as i previously said that one of the cells in the battery is dead.

Just for info purposes here is a link to how brushless car alternators work:

https://speedalternators.com/brushless-alternator

Interesting stuff eh? So there are magnets and windings inside the rotor which are excited by a stator winding - the resulting magnetic field amplified by motion is then picked up and rectified via the three phase stator windings hence removing the need for brushes - genius. But for the bearings and the lifetime of the semiconductors, these units could go on forever.

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On 6/22/2023 at 4:49 PM, unofix said:

Have you disconnected the charge control plug from the alternator ?

No you can't replace the brushes on your 3 phase alternator, it doesn't have any.

Have you had the battery load tested ?

Went to Halfords today and had the test - the battery was declared good but a bit low on charge. Went away happy with this result until...my ABS light came on during the trip home - first time it's ever come on - a coincidence or a linked event? Is there a common cause for the ABS light to suddenly come on whilst moving but was not operating the brake...?

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2 minutes ago, Oriskany said:

Is there a common cause for the ABS light to suddenly come on whilst moving but was not operating the brake...?

Check the plug to the ABS module.  May have been knocked while testing the battery.

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3 hours ago, TomsFocus said:

Check the plug to the ABS module.  May have been knocked while testing the battery.

Did this - difficult to access but ok when I discovered how to use the release lever. On the battery front I finally gave up messing about and bought a new Calcium battery - let's see if all returns to normal.

BTW I came across an article which stated that a good lead acid battery lasts on average 12-18 months in the hands of the Ford smart charge system due to the higher charging voltages - mine lasted just short of 18 months so it's true as far as my experience showed.

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Just to round off - the new battery has done the trick. The ABS light has stayed off and I feel that this fault was due to intermittent battery performance, especially as the ABS light used to flash whilst starting the engine and the speedo needle also jittered about also.

Lesson learned the hard way - on the Mk 1 Ka with the Duratec engine only use a Calcium battery! - I cannot speak for the Endura E though.

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Spoke too soon! Yesterday I got in the Ka, started it and the battery light came on after 20 seconds! A quick look at my (new) battery revealed that the state of charge indicator has changed from green to black so all that happened is that the full charge state of my new battery masked the problem for a while.

I re-visited the three pin connector on the alternator and found that the red wire carries the same voltage as the battery, the third wire carries some 8v showing that it is connected to something and the centre wire carries a few millivolts - unsurprising as it is a "sensor out" connection.

I have looked unsuccessfully for the ecu to check continuity of wires and possible dry joints in there - where is it pls and is it easy to get out? Haynes doesn't show it. Also any other ideas welcome as (1) if I disconnect the smart charge plug the battery goes to 13.8v like a regular alternator so the alternator isn't dead and (2) this must have happened to someone else before. The 3a alternator fuse is intact and all of the relays well seated. Thanks.

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Didn't want to be negative before but I've seen lead acid batteries wreck a SmartCharge alternator on a few different Fords.

Hopefully that's not the case here and you'll find a wiring fault instead.

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I've temporarily removed the smart charge plug as the battery voltage stays at 13.8v and does not change due to applied loads - like a regular alternator. I'll see how it goes and I've waterproofed the connector and socket in case I get it going again in the future.

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Not wanting to appear thick here, but where is the ecu situated in a 1.3 2006 Duratec pls? Thanks.

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33 minutes ago, Oriskany said:

Not wanting to appear thick here, but where is the ecu situated in a 1.3 2006 Duratec pls? Thanks.

It's inside the car.  Mounted to the left hand side of the passenger foot well (RHD).  It's tamper-proof and a right pain to remove.  

You're meant to remove the dashboard first, but there are ways of bodging it with a hacksaw and perseverance.

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I've been running my Ka with the smart charge plug disconnected and the new Calcium battery for six days or so now, and ignoring the battery light.

The voltage with engine running is 13.8v however today, after a good run the "resting - engine off" battery voltage sits at 13v - is this a safe situation as I've never seen a battery voltage like that before, but also never also owned a past Calcium battery.

Does a Ford smart charge alternator really revert to a normal alternator with smart charge disconnected? It looks as though it does as smart charge voltages are rumoured to be as high as 17v under certain circumstances.

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With the smart plug disconnected the alternator will default to the 'emergency' charge voltage of between 13.6 and 13.8 Volt. This is not the same as an old style 'dumb' alternator who's charging was regulated externally.

You will cook your battery if you continue to run it with the alternator charging at 13.8V

The standing voltage of a fully charged 12V battery one hour after standing should be approx 12.65 to 12.70V maximum.

Ford - Battery SOC.JPG

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Reconnected the Smart Charge plug in respect of the above and the battery light came on after 30 seconds as expected.

I then switched off and re-started the car three times, left it idling whilst I switched various things on on off and lo....the battery light went out and hasn't reappeared.

My theory is that my lead acid battery simply failed and the battery light came on to indicate that no charging was occurring due to the dud battery.

I bought a new Calcium battery, installed it and immediately reacted to the battery light coming on by disconnecting the Smart Charge plug. Having only owned older cars I am used to the light going out immediately after correcting a problem and jumped the gun. All that was needed was to leave things as-is with the new battery and wait for the ecu to recognise that the problem had been corrected!

Top Tip - if your battery light comes on and you replace your battery just be patient and wait for the light to go out before inventing all sorts of complex faults like I did.

Let's hope it stays out now...

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