Alternator/Battery Problem Leading To......

[kenntona]

I had encountered this problem last Thursday. Cranked my car, drove off in SD mode (as usual), but as I left the carpark, Christmas lightings appeared on my instrumental cluster. All these indicators lit up - ASC, ABS, airbag, handbrake, canopy. Stopped the car, came out and check the capacitor - it reads 13+ volts. Xenon headlights were working fine. Drove off.

On the expressway, the power on the stereo was cut off, followed by the aircon - fan was still running, but no cold air coming in. Then the fear factor came about...... I could neither upshift nor downshift at expressway speed !!! Switch to paddleshift, it was reading M4 when I upshifted, M2 when I downshifted, but the gear was not changing. When I reached local traffic, the car moved off the traffic lights on THIRD gear. A small exclamation mark with a circle around it appeared between the letters S and D on the instrumental panel. Never seen that before.

Brought the car to BVO on Friday morning. Reached there, called for cab, then tried to crank again - dead !!! Lucky did not drive to work.

Diagnosis? Ah Wee said bad battery. Belt was changed after Christmas. Alternator working fine. Battery was changed (VARTA), reset my HU, peace after that. Boh tai ji liao......

Two questions lingered, assuming it was not the case of a faulty alternator:

(1) if the output is not flowing through, is it true that functions and gadgets dependent on electronics like gearshift (perhaps fuel throttle) cannot be overridden manually? That is a scary thought, but I really could not downshift....... Any impact on the ECU?

(2) the battery output did not taper off. It is more like cliff-drop on its last day. No sign of predicting it? Now, how else could we tell about a dying battery?

 

[como]

Re: Alternator/Battery Problem Leading To......

it happen to me on my previous car.......normally the signs of a weak or dying battery is that u are starting to take a longer time to crank it to start.

a good batt normally takes abt 1 crank and the engine will roar to life....weak batt will takes about 2 or more cranks.

ur case is a bit weird.....it should not affect the shifting of gears....

 

[ferd]

Re: Alternator/Battery Problem Leading To......

in my e46, I noticed these symptoms, weaker & longer crank when starting engine
if you leave your door open for long (grooming sessions), after that always cannot start.. a quick check on the alternator showed its charging properly.... so those were tell tales signs that the battery was gonna die.

for your case its scary! i mean alternator should be still supplying power....so the rest of the electronics should be still functioning

 

[hitmee]

Re: Alternator/Battery Problem Leading To......

i think best to change battery every 1.5 years.

 

[satinGHOST|r!der]

Re: Alternator/Battery Problem Leading To......

I had encountered this problem last Thursday. Cranked my car, drove off in SD mode (as usual), but as I left the carpark, Christmas lightings appeared on my instrumental cluster. All these indicators lit up - ASC, ABS, airbag, handbrake, canopy. Stopped the car, came out and check the capacitor - it reads 13+ volts. Xenon headlights were working fine. Drove off.

On the expressway, the power on the stereo was cut off, followed by the aircon - fan was still running, but no cold air coming in. Then the fear factor came about...... I could neither upshift nor downshift at expressway speed !!! Switch to paddleshift, it was reading M4 when I upshifted, M2 when I downshifted, but the gear was not changing. When I reached local traffic, the car moved off the traffic lights on THIRD gear. A small exclamation mark with a circle around it appeared between the letters S and D on the instrumental panel. Never seen that before.

Brought the car to BVO on Friday morning. Reached there, called for cab, then tried to crank again - dead !!! Lucky did not drive to work.

Diagnosis? Ah Wee said bad battery. Belt was changed after Christmas. Alternator working fine. Battery was changed (VARTA), reset my HU, peace after that. Boh tai ji liao......

Two questions lingered, assuming it was not the case of a faulty alternator:

(1) if the output is not flowing through, is it true that functions and gadgets dependent on electronics like gearshift (perhaps fuel throttle) cannot be overridden manually? That is a scary thought, but I really could not downshift....... Any impact on the ECU?

(2) the battery output did not taper off. It is more like cliff-drop on its last day. No sign of predicting it? Now, how else could we tell about a dying battery?

Ken,

i had a problem relating to battery a week back. i was abotu to move off but no power. everything was working though as in the lights and radio were all operational. But engine is stalled. THe battery and engine oil light lit up and i cranked again and it worked. Bernard changed my battery based on suspicion but the problem came up again. So he resetted all my fault codes so far and now seems ok. i just hope nothing is wrong. As for the battery, if u realise, there are 3 color codes. Mine was black color when bernard took it out. It meant insufficient charge. Yellow means totally dead and green means ok. Hope this helps as another marker to check ur battery.

Cheers.

P.S - Ken, i think ur car and my car fate almost same leh. Even the other time, we had the same problem at BVO. hahaha...

 

[martmode8850]

Re: Alternator/Battery Problem Leading To......

bro... how old was your previous batt??? should be able to last at least 2 years if you are without upgraded ICE...

also, the alternator should be able to last 7-8 years or 150k km average... so, your alternator should still be good...

but not being able to shift (up/down) is certainly scary...

 

[kenntona]

Re: Alternator/Battery Problem Leading To......

Ken, i think ur car and my car fate almost same leh. Even the other time, we had the same problem at BVO. hahaha...

bro... how old was your previous batt??? should be able to last at least 2 years if you are without upgraded ICE...

also, the alternator should be able to last 7-8 years or 150k km average... so, your alternator should still be good...

but not being able to shift (up/down) is certainly scary...

Well, battery was about 2 years old, but car heavily ICEd, hence.....

My point is this - how could the electronic functions be so dependent on power from battery that the ECU could not allow for gearshift? Furthermore, my impression was that once the car is moving, the alternator takes over the power output function. How then could my car not be able to shift gears on steptronic mode? Unless, of course, the alternator is down - but that has not been proven so far, after the battery change...... Everything is back to normal.

If this is a specific case, then no biggie about it.

But if this is an inherent power circuitory problem, then I think the forumers need to be informed about this.

 

[LimPeh]

Re: Alternator/Battery Problem Leading To......

I had a similar problem on Christmas eve. While merging expressway, my dashboard lights flashed like a christmas tree, the wipers danced non-stop, engine non-responsive and loosing power.

I pulled aside, turned off engine and restarted. The car continued to flash like a christmas tree. Something must have told it that its Christmas eve.

The engine was back to normal but the lights continued to flash and wipers swing non-stop. Signal lights don't work and engine check error lights up. Active steering also failed but thank God the car is still driveable.

The problem disappeared completely on the next day and there was no trace of any problems. I sent the car to PML and they could not find anything wrong with the car either. Alternator and battery health was good and they told me that the problem could be caused by my ICE. I find it hard to accept this conclusion because:

1. my ICE was not operating when the failure occurred
2. my ICE was installed without changing any of the car's original wiring
3. I'm only tapping the audio output from the original rear amplifier

Someone told me that the large 3 Farad capacity for my ICE could have caused the failure. If the capacitor is working as it should, there should not be any problems. The capacitor is supposed to prevent a sudden demand of current supply from the battery. A faulty capacitor may cause a current surge instead of preventing it. When this happens, there is a chance that the power surge can cause our BMW electronics to behave erratically.

For my case, my ICE was not operating during the time of failure, if there is any current surge, it should be caused by the capacitor. Maybe I'll have it removed to be checked thoroughly.

By the way for those heavily ICEd brothers here, do you get "High Current Discharge" message from your iDrive once a while?

 

[martmode8850]

Re: Alternator/Battery Problem Leading To......

some battery info i took off the net... the alternator should be supplying power, however if some other equipment (eg battery) is drawing too much power from it because it is dead, it can and will cause a power failure...

How do I know if my battery is failing?
There are several warning signals your battery will give you that will indicate there is going to be a problem. Here are some things to look for. First, you want to look for the age of the current battery. The average car battery lasts 38 months. The average camcorder battery lasts 26 months. The older any battery is, the more likely it needs to be replaced. In your car, if your motor turns over slowly or in an interrupted manner or if you lose power quickly in cold weather or if your headlights dim when you are idling, you should seek a qualified battery technician for testing and evaluation. In any electronic device your run time will gradually decrease. When this happens, its best to start thinking about battery replacement.
What causes car battery failure?
There are several external factors that contribute to battery failure. Excessive heat causes the positive plate to quickly corrode and this dries out the battery cells. This is probably the number 1 reason for failure. Extreme Cold weather makes your engine harder to crank because the oil thickens in your car and this puts a heavier drain the battery. This also is a contributor to failure. If your battery isn?t securely held down, vibration will shed the active material from the batteries plate grids. This will cause failure. Overcharging causes a battery to over heat and cause gassing. This is where the electrolyte turns from a liquid to a gas and is expelled out of the vent holes, leaving the plates exposed. Soon the plates will short and the battery will fail. Other factors that can cause battery failure include corroded cables and/or terminals, sulfation due to inactivity, alternator and/or regulator malfunction or electrical shorts in the battery itself.
What can I do to help preserve battery life in my car?
Follow these guidelines every 3-6 months and you can extend the life of your car battery.

A. Check for cleanliness ? If the battery tray is dirty or corroded, remove the battery cables first then remove the battery from the vehicle. Wash the battery tray with a water and baking soda solution. Flush the tray with water and dry off with a paper towel. If necessary, clean the battery posts and the cable terminals with a wire brush or a special terminal cleaning tool. You can also wash the battery with the baking soda and water solution, however, be sure the vent caps (if the battery is not sealed) are on tight to prevent anything from entering into the cells. A clean battery, with clean terminals in a clean tray will ensure the best connection.

B. Check hold down brackets ? Make sure the brackets holding the battery to the vehicle?s frame are secure. Excessive vibration will cause premature failure in your battery. If the brackets are loose, tighten them up and spray them with a corrosion preventative spray. This will keep the corrosion from rebuilding.

C. Check your battery cables at the battery ? Battery cable connections to the terminal should be checked for corrosion and proper tightness. Clean off the terminals with a wire brush and spray with corrosion preventative spray on them. Tighten all bolts as necessary. Also, check the cable itself for swelling, cracking or brittleness. If you notice any of these symptoms, replace your cable immediately.

D. Check your ground cable at the frame ? Make sure your ground cable is securely fastened at the frame. Also, make sure the connection is clean. This connection gets overlooked quite often. A quick check once in awhile could save you a big headache down the road.

E. Check the battery case ? The condition of the battery case often will indicate if you have a problem. If your case is "swollen" on the sides (concave) there is probably a charging system problem. If your case is cracked or your battery post "wiggles" your battery should be replaced. These problems are non repairable. Your car may start today, but it is recommended to replace it before your stranded.

F. Check fluid levels ? On a non-maintenance free battery, remove the vent caps and check on the fluid level. If you see fluid, the battery is fine. If, when looking in the cell, you see an exposed lead plate, you need to add distilled water immediately. Do not add battery acid. Adding a premixed electrolyte solution will make the sulfuric acid too strong and will damage the plates and separators. Be careful not to overfill each cell. The fluid level should stop approximately 1" under the top of the battery. Make sure the plates are covered.

 

[yendor]

Re: Alternator/Battery Problem Leading To......

Ken,

The signs that you mentioned are classical for a weak/dyinmg battery. The problem is calcificationof the battery and that increases the internal resistance of the battery. the more calcium build up on the plates, the higher the internal resistance. If your capacitor voltage reads nnnnnnn) The voltage is now about 18-20V DC and to further clamp the voltage down to the charging voltage of around 14.2V, a voltage regualtor is used. If there was no battery to charge, there would be a ripple in the voltage waveform...( looks like a series of bras nnnnn with the tips flattened, the valleys in between peaks are still present) So the battery fills in these small valleys with power.

So when your battery is weak, these vallies are more apparent and thus your car's power supply becomes corrupted with some AC power and this corrupts the computer circuits. Not really a big thing but it may cause electronic devices to go haywire. Once the battery is changed and faults erased (some times the eratic behaviour trips a fault code and sends the car to safe mode) the car should be back to normal.

Cheers