[Rehaan]

I THINK WE CAN ALL AGREE THAT :

It is a sudden drop in battery output that is responsible for this hiccup. Agreed?



Mainly 2 things are responsible as the trigger of this sudden drop in output

1) Radiator fan turning on.
Notice the extremely high Surge Current for a DC motor, in the first second or so of turning on :


2) AC Compressor clutch (since after all, it is a large electromagnet / coil too!)



But what is the ROOT cause?

1) The battery voltage might be a little less than optimal at times, since the ELD isn't noticing a high discharge rate and is therefore charging it at lazy intervals.

2) The ELD has reduced (or turned off?) the alternator, which therefore puts ALL the draw on the battery for that split second that the radiator fan or AC compressor engage.



So what happens when that sudden load hits?

The battery takes the hit, and therefore the voltage drops for that split second, causing either the amps to cut-out, (or perhaps the HU preamp to do so?).
Monitoring voltage on an analog voltmeter or an oscilloscope will help confirm that this drop is infact happening.



But...why didn't the sound dip with the stock system?

Perhaps the HU isn't as sensitive to drops in voltage as these amps are (see navin's earlier posts mentioning 12.5 volt cutout for the amps), which is probably higher than the cut-out for the head unit.



POSSIBLE SOLUTIONS?

1) Wire some other component through the ELD. Either 1 amp, or the Head Unit. This will keep some load on the ELD and make run that alternator more agressively, which IS required with a system like this. (Same thing has been mentioned by gigy)

2) A capacitor might help eat that surge current, and therefore keep the amps above their required 12.5volts.

3) Disconnect radiator fan and dont use the AC

4) Use amps less sensitive to large voltage drops??

5) Switch to a healthier/new battery with a better CCA rating.

.... what else ??



Any possible flaws in the argument above?


cya
R


Source of graph

[Rehaan]

Originally Posted by navin

ok I got a mad mad idea....keep playing with your power windows thereby ensuring the ELD is always sensing a higher current draw and asking the alternator to charge the battery fast.

Its funny you mention this navin, this is exactly what i did yesterday.

A few observations from a 10 minute drive :
- About 7 minutes into the drive the sound dipped whilst standing at a traffic signal.
- I took the opportunity to turn the AC on and off 3 times consecutively, and every time i did so, the sound dipped!
- I turned the headlights on and kept the power window switches pulled up, even though the windows were up (since this puts more load on the system than just using the power windows in the conventional way).
- After that, i couldn't get the sound to dip, though i didn't really have the opportunity to try for too long as we reached our destination very soon after.

Originally Posted by Mpower

Could be that 1 sec is the reaction time for the ELD to detect the high load and switch the field back to 'high outupt' mode.

It could be.
However, i personally think its more likely that its a large surge current draw (the same way as the lights in your house sometimes dim when the AC compressor turns on). Lasts just for a second. Exact same thing happening here.

ELD is just a current sensing hall effect sensor. has the function of load detection and protection.

So the ELD measures current draw. There must be another trigger for the alternator as well for low voltage -- is that controlled by the ECU??
More details please...


cya
R

[gigy]

May be this is a begining symptons of weaking battery.

try running one day with airconditioning off and see if the frequency of dips reduce.

swap for a new battery and have a ride

by standard
- alternator will supply all electrical load possible in car with a margin for momentary surges and also a small margin to charge battery,
-alternator voltage will not fall below 12v. voltage will be self regulating

[Mpower]

Originally Posted by Rehaan

However, i personally think its more likely that its a large surge current draw (the same way as the lights in your house sometimes dim when the AC compressor turns on). Lasts just for a second. [b]Exact same thing happening here...

Agreed but if the ICE is already playing, where is the sudden current draw coming from 7 mins into the drive? Did you hear the fan coming on?

BTW, happens is cars too. My ex-battery, on its last days...you would see the headlights dim and music cutoff for a second when you started the car..but thats more of a battery thing. (ie if you started the car with music and lights on)

Originally Posted by Rehaan

So the ELD measures current draw. There must be another trigger for the alternator as well for low voltage -- is that controlled by the ECU??
More details please...

Another key trigger is should/would be battery SOC

[montyguru]

Originally Posted by Rehaan

A few observations from a 10 minute drive :
- About 7 minutes into the drive the sound dipped whilst standing at a traffic signal.
- I took the opportunity to turn the AC on and off 3 times consecutively, and every time i did so, the sound dipped!

Originally Posted by gigy

May be this is a begining symptons of weaking battery.

try running one day with airconditioning off and see if the frequency of dips reduce.

swap for a new battery and have a ride

by standard
- alternator will supply all electrical load possible in car with a margin for momentary surges and also a small margin to charge battery,
-alternator voltage will not fall below 12v. voltage will be self regulating

+1
clearly a weakening battery unable to take momentary surges. a new battery should solve the problem.

[navin]

Originally Posted by valhallen.282

The general lee you're right featured the 69 version. They had a 318 68 model, 380 69 and the 440 bigblock that I speak of.

there is no substitute for cubic inches though I must say I am impressed with the ammount of horses they can wring out of a 1.5-2 liter engine today. The Mini Cooper S for example has a 1.8l oil burner that put out 180 horses with torque too boot. 180 horses on a Mini! I can see fun.

Originally Posted by Rehaan

It is a sudden drop in battery output that is responsible for this hiccup.
1) Radiator fan turning on.
2) AC Compressor clutch (since after all, it is a large electromagnet / coil too!)

1) The battery voltage might be a little less than optimal at times, since the ELD isn't noticing a high discharge rate and is therefore charging it at lazy intervals.

2) The ELD has reduced (or turned off?) the alternator, which therefore puts ALL the draw on the battery for that split second that the radiator fan or AC compressor engage.

Monitoring voltage on an analog voltmeter or an oscilloscope will help confirm that this drop is infact happening.

But...why didn't the sound dip with the stock system?

1) Wire some other component through the ELD.
2) A capacitor might help eat that surge current
3) Disconnect radiator fan and dont use the AC
4) Use amps less sensitive to large voltage drops??
5) Switch to a healthier/new battery with a better CCA rating.

1. lets not mess with the OEM electricals unless as a last resort solution though I agree that a HU will not cause much of a load (espcially when the internal amps are not being used).

2. I suggested a cap na? It is easy to install and remove and I am sure we can get a loner.

3. I think GTO will not like that

4. also suggested but a little more work than a cap.

5. also more work that installing a cap.

what has foxed me why with just 2 DLS amps working (the sub amp is the biggest power hog) the sound still dipped.


This is why I prefer option 4 out of all the ones suggested.

Originally Posted by gigy

- alternator will supply all electrical load possible in car with a margin for momentary surges and also a small margin to charge battery,
-alternator voltage will not fall below 12v. voltage will be self regulating

The ELD controls the alternator so even though the alternator is capable it's output is electrically limited by the ELD (when the ELD assumes the battery has enough juice for it's functions).The ELD does not know there are amps in the circuit.

Originally Posted by montyguru

+1
clearly a weakening battery unable to take momentary surges. a new battery should solve the problem.

A weakened battery will not have cranking amps to start the car after 3 days.

[gigy]

As far as i know a car battery has only two functions in normal cars
-start the car
-act as a surge suppresant and assist the alternator for a very small amount of time

Its also a emergency power when alternator has failed and can continue running the car electricals for few kms.

ELD is not monitoring battery, so it cannot assume.
ELD is monitoring alternator output. A drop in total terminal voltage of alternator kicks it in to pump up the voltage of excitation circuit.

So in a non-normal setup you will have to provide this constant kick to save the battery and also the alternator. so when the disco is in progress keep kicking.

or keep a switch to, switch speakers to headunit amplifier or the power amplifiers

[Rehaan]

Originally Posted by Mpower

Agreed but if the ICE is already playing, where is the sudden current draw coming from 7 mins into the drive? Did you hear the fan coming on?

As mentioned, probably the radiator fan or AC clutch.
With the ICE playing its impossible to hear the radiator fan come on...

Originally Posted by Mpower

Another key trigger is should/would be battery SOC

I'd imagine thats a prerequisite / condition in order for the ac/fan to actually trigger this problem.

Originally Posted by navin

2. I suggested a cap na?

Yea! I quoted + agreed to your suggestion earlier na?
Its a plug and play solution. Lets see if it works.... How big a cap?

Originally Posted by navin

what has foxed me why with just 2 DLS amps working (the sub amp is the biggest power hog) the sound still dipped....

IMHO its because (in theory) this has nothing to do with the combined power-draw of the amplifiers!

It has to do with the power supply system (Batt + ELD + Alternator) not being able to keep the voltage over the required 12.5v for these amps for the split second that the fan or ac comes on.

Though the amplifiers are responsible for lowering the battery charge at a faster rate, and therefore perhaps bringing on this condition sooner once hitting traffic?

cya
R

[navin]

Originally Posted by gigy

ELD is not monitoring battery, so it cannot assume.
ELD is monitoring alternator output. A drop in total terminal voltage of alternator kicks it in to pump up the voltage of excitation circuit.

fair enough I am not conversant with the ELD but the effect is the same.

Originally Posted by Rehaan

I'd imagine thats a prerequisite / condition in order for the ac/fan to actually trigger this problem.Its a plug and play solution. Lets see if it works.... How big a cap?

It has to do with the power supply system (Batt + ELD + Alternator) not being able to keep the voltage over the required 12.5v for these amps for the split second that the fan or ac comes on.

If it just the radiator fan wont this be true for all cars not just Civics. The mad man from Freed-a-bad has a much bigger system on a stock alternator-battery in his Swift though I am not so sure of if the engine of his car is still attachedm to it's moorings.

Yet if it is radiator fan and the issue is 1 sec every minute then a cap will help. Normally the thumb rule is 1F for every KW. For GTO's car I'd say 2F should be ok. 5F cap would be too big and not available as a loner (not enough volume in the market).

GTO try the cap na? If it does not help we'll install Steg/JL(HD series) etc...and see if that helps.

[valhallen.282]

Pardon me but I'm finding this amusing. We have assumed its a power problem. Without ensuring its not a connectivity issue. We don't know what is losing power. We don't know if the amps are going to protect and/or switching off. We haven't confirmed that this is happening even with a externally powered source.

So it happened with ELD in another car I'm certain there are a number of civics out there running tricked out systems. We should have more complaints than one here right? Can we first be sure that its not the source or the amps please. Or atleast figure out that the amps are NOT shutting down. Geez I'm beginning to sound like my old man.

[navin]

Originally Posted by valhallen.282

Pardon me but I'm finding this amusing. We have assumed its a power problem. Without ensuring its not a connectivity issue. We don't know what is losing power. We don't know if the amps are going to protect and/or switching off. We haven't confirmed that this is happening even with a externally powered source.

The reason we have sorta ruled out a connectivity issue is that the system has been looked at more than one and all connections were checked when the problem first surfaced. Hence if there was a connectivity issue (a bad / loose power cable for the HU for example) this would have been noticed. Also as GTO says the problem only happens at very low speeds and very low rpms (idling). It is at idling that the alternator puts out the least voltage.

[valhallen.282]

Very well. That's a fair argument. How about moving to two amps instead of three. Like a 4 channel from JL/Harmon Kardon/audison LrX. Or an even weirder idea. Try a single 4.1/5.1 amp. I had researched for one a while ago. There was a nice audison.

[Mpower]

Originally Posted by gigy

ELD is not monitoring battery, so it cannot assume.
ELD is monitoring alternator output. A drop in total terminal voltage of alternator kicks it in to pump up the voltage of excitation circuit.

ELD is a sensor that feeds into to the ECM which in turn is whats controlling the alt. Batt SOC is another sensor.

Originally Posted by Rehaan

As mentioned, probably the radiator fan or AC clutch.

Surge current from Rad fan you think? Yup guess thats a possibility.

[navin]

Originally Posted by valhallen.282

Very well. That's a fair argument. How about moving to two amps instead of three.

It is an option we are going to consider if it is indeed determined that it is current draw from the amps. The options are a DLS CA41, Infinity Kappa 4, JL 300/4, etc..all of these are about 70Wx4.

[Rehaan]

Originally Posted by navin

If it just the radiator fan wont this be true for all cars not just Civics.

True point. But could it be a weak battery at play here?
Also, which other cars have ELDs set up like the civic?? The fact that the alternator is not charing at full power plays a part here (which would not be the case in say LBM's swift).

Also can you confirm the required voltage for all 3 amps is 12.5 in this case? Or is it higher?
Whats the typical required voltage for other amps?

Originally Posted by valhallen.282

Very well. That's a fair argument. How about moving to two amps instead of three.

Add to that, the fact that it happened 3 times in a row each time i turned on the AC. That doesn't sound like a connection issue.

Regarding two amps -- the sub amp had been removed when the above happened.

Originally Posted by Mpower

Surge current from Rad fan you think?

Yea... see my post (first one on page8) incase you missed it?

cya
R

PS - There's only so much we can theorize.... i think its time some theories here get validated. Perhaps starting with monitoring the voltage as this happens? Or maybe even just switching the battery with one from another car! Whats on the cards B&T?