General battery icon on the dash

[edesl]

Today my Bravo T-Jet Sport showed up a battery icon on the dash. Nothing associated text message. What is its meaning?
By the way, the charging system is good as in this time the plug in voltmeter in the cigarette lighter socket showed 14V.

Is there any list about possible icons that may appear at this position?
BR
L

 

[bfbenf]

Means your battery isn't charging. Which most likely your alternator. Id perform an alternator test.

 

[bfbenf]

Oh? Didn't read that fully? Any codes stored?

 

[portland_bill]

Here's a problem as old as alternators themselves, although not seen it for a long time. Old Lucas alternators used to do this regularly.
The alternator usually contains 9 diodes. Six control the charging, changing the alternating current to direct for the car's systems. The other three convert the alternating current just to control the warning light.
A light on, but still charging ok, will usually mean those diodes have failed. It may be possible to replace a diode pack, but it is a lot of work, so compare with a replacement alternator, especially if you can't do the diode pack yourself.
When these diodes fail, they can allow the battery to discharge through the alternator when everything is off, so would be a good idea to check this. If used daily, it'll likely be ok for a while, but will worsen, and coming into winter might leave you stranded without enough in the battery to start it.

 

[g8rpi]

Here's a problem as old as alternators themselves, although not seen it for a long time. Old Lucas alternators used to do this regularly.
The alternator usually contains 9 diodes. Six control the charging, changing the alternating current to direct for the car's systems. The other three convert the alternating current just to control the warning light.
A light on, but still charging ok, will usually mean those diodes have failed. It may be possible to replace a diode pack, but it is a lot of work, so compare with a replacement alternator, especially if you can't do the diode pack yourself.
When these diodes fail, they can allow the battery to discharge through the alternator when everything is off, so would be a good idea to check this. If used daily, it'll likely be ok for a while, but will worsen, and coming into winter might leave you stranded without enough in the battery to start it.

While this is correct, the full picture is more complex. The three auxillary diodes also power the regulator (and field on some designs) with the current through the "battery" warning light providing the current to kickstart or "bootstrap" the regulator until the alternator starts to produce power. With these earlier designs if the bulb fails the alternator will also fail to produce power (sometimes there is enough residual magnetism to get things started this is how dynamos start) and you get no warning unless you check the bulb comes on before you start the engine. Modern systems can be different as the warning indicatior is not connectted directly to the alternator.
Fixing alternators is not too difficult. I just replace the rectifier pack on my Croma's 140A alternator. The part was £15 and took 15-20 minutes to fit. Getting the alternator out and back in on a RHD Croma is the hard bit. Still £15-25 for a rectifier is better than £90-£250 for a recon or exchange alternator.

Robert G8RPI.

 

[portland_bill]

While this is correct, the full picture is more complex. The three auxillary diodes also power the regulator (and field on some designs) with the current through the "battery" warning light providing the current to kickstart or "bootstrap" the regulator until the alternator starts to produce power. With these earlier designs if the bulb fails the alternator will also fail to produce power (sometimes there is enough residual magnetism to get things started this is how dynamos start) and you get no warning unless you check the bulb comes on before you start the engine. Modern systems can be different as the warning indicatior is not connectted directly to the alternator.
Fixing alternators is not too difficult. I just replace the rectifier pack on my Croma's 140A alternator. The part was £15 and took 15-20 minutes to fit. Getting the alternator out and back in on a RHD Croma is the hard bit. Still £15-25 for a rectifier is better than £90-£250 for a recon or exchange alternator.

Robert G8RPI.

That was the original 'battery sensed' alternators. Warning light blows, no charge. I doubt any are like that these days, all will be 'machine sensed', so don't rely on the warning light to operate. I've had several Fiats pop a warning light over the years, all continued charging, but all required replacement as they would discharge the battery.

I've found on some of mine, the slip rings wear more than the brushes, and replacing slip rings is more difficult. Replacing the whole thing is easier, and comes with a warranty. Always worth having a look though.

 

[g8rpi]

That was the original 'battery sensed' alternators. Warning light blows, no charge. I doubt any are like that these days, all will be 'machine sensed', so don't rely on the warning light to operate. I've had several Fiats pop a warning light over the years, all continued charging, but all required replacement as they would discharge the battery.

I've found on some of mine, the slip rings wear more than the brushes, and replacing slip rings is more difficult. Replacing the whole thing is easier, and comes with a warranty. Always worth having a look though.

Hi Bill,
Most modern systems are battery sensed or variable output controlled by the ECU. Machine sensing is not accurate enough for modern batteries, heavy loads and electronics.


Robert G8RPI

 

[edesl]

Means your battery isn't charging. Which most likely your alternator. Id perform an alternator test.

as wrote, the charging was 14V in the same time, I have a voltmeter in the cigarette lighter socket.

 

[portland_bill]

It is still the most likely fault that the charging diodes are still fine, but the warning light ones have a failure.
If you can live with the light on, and rely on your voltmeter, just run with it until it gives up charging.