[valhallen.282]

Originally Posted by GTO

*UPDATE*
- Electrical system OK.
Now what?

NOW load test. Disconnect amp sir. Does not seem to be any other simpler solution.

[GTO]

Originally Posted by Invinsible

Why not check the charging when amps goes off ?

The amps go off for 0.5 seconds when driving. How can I check the charging then? And either ways, I think its pretty clear that the car's electrical system is performing as intended. There is no fault as such with the battery or alternator.

Originally Posted by valhallen.282

Disconnect amp sir. Does not seem to be any other simpler solution.

Thanks. Lets see what the other gurus have to say, then we'll decide on the way forward.

[Invinsible]

Why not keep the voltage check meter on the battery when you are the battery guy. Start the car, put the system on and read the voltage meter if there is any drop in voltage while putting the system on and when the amp goes off.
The question we want to rule out is if the ELD / ECU sends the signal to the battery how much voltage to put out on various load condition, there should be a drop in voltage when you put on those amps or when it goes off for that 0.5secs. We need to know what that figure is.

[navin]

Originally Posted by GTO

*UPDATE*
Electricals thoroughly checked

It is the ELD. The ELD is limiting the alternator's current to the battery hence the battery is not charging current as fast as the amps are discharging the battery. see post http://www.team-bhp.com/forum/2126746-post54.html

the options we have are
a. draw fewer electrical amps from the battery so that the amplifiers discharge the battery slower than the alternator-ELD combo charges it.
b. trick the ELD into asking the alternator to chrage the battery faster
c. install a secondary power source for the audio system (involves upgraded alternator, second battery and dual battery isolator).

In the old days there was no ELD and no Class D amps hence option c was the only option. Today Class D amplifers are much more effcient (in converting power drawn from battery into power fed to speakers) than Class AB amplfiers. So for option a. there are 2 sub options

i. Change Subwoofer amp to Class D
ii. Change DLS amps to amplifiers that are better regulated (Class AB amps) like Steg etc..Steg amps can operate at lower then 12.5V while apparently DLS amps might not be able to operate at low voltages.

I recommend option i. as it should work easiest.

Originally Posted by GTO

The amps go off for 0.5 seconds when driving. How can I check the charging then?

arey baba simple..
a. connect voltmeter across battery terminals
b. turn car on, neutral gear, parking brake, idling rpm and read battery voltage
c. turn stereo on read battery voltage and watch for any drop in voltage

an even simpler method
Disconnect the rear channels amp (DLS) and use the system for a few days. if the system works you are sure that it is a problem where the battery is discharging at a rate that is faster than the charging rate of the alternator-ELD combination.

[DerAlte]

The only way one can visually detect voltage dips of such short duration would be either a strip chart recorder or one of those old galvanic meters like the Motwane or Toshniwal multimeters . Maybe a good CRO on slow scan or triggered single shot. DVM / DMM won't get it - too slow.

There are no symptoms of malfunction of the HU itself - the interruptions would be random, and wouldn't stop during idling etc. All pointers are towards the ELD, unless we all are missing some other obvious influences on the 12V line. We should try figuring out whether the ELD + the regulating part in the ECU is doing what it is supposed - jack up the field excitation of the alternator when the voltage dips.

If the ELD is really working OK (correcting the voltage dip), then we are looking at the wrong end of the event (post-event, rather than pre-event; event = dip in 12V with amp and other electrical loads on). This may be a wierd boundary condition due the sudden increases in load on the electrical system (bursts of low frequencies in the sub or such), sensed by ECU (via ELD) as a trigger condition, and the increased excitation to the alternator restoring sanity. May be the ELD is a bit too sensitive in these load conditions? Maybe there is a loose or oxidized connection?

[Mpower]

Originally Posted by navin

The ELD was installed to protect the alternator. If your alternator cannot produce the required current to power everything in your car, including your stereo system, it will at some point begin to draw too much current, and the coils withing it will overheat causing the enamel to melt, and the alternator to fail. By limiting current draw the ELD ensures the alternator is not damaged if too make accessories are isntalled

MPower, would the overdrive pulley work if in fact the feedback loop from battery to alternator via the ELD is controlling the charging rate of the battery?

My understanding of the problem is

The battery is discharging at a rate that is faster than the max charging rate of the alternator-ELD combination. I also believe that since the car worked after being left idle for 3 days and also worked for the first few months that this difference in charging/discharging rates is marginal.

The ELD theory makes sense. Its more of a FE enabler and switches the Alternator to low power mode during traffic crawl (during which the engine is least efficient). However I'm surprised its not able to detect the additional draw and compensate for that.

With the pulley, the electrical field stays same (low power mode) but you get more Alternator rpm.

Long shot, but one way to test ELD is to swap out a weak battery. Low batt voltage should force the ELD to switch to how power mode.

[gigy]

May be you can try this take the least powerful amplifier and connect it after the ELD. this will keep up the demand and force the alternator to pump out more power in the bargain the hidden amplifiers will also benefit.

You also need a 20% bigger new battery first with this.

Also check out the operating voltages of all the amplifiers you are having, maybe one of them needs above 12v to work without going to protective shutdown. anytime system voltage goes below it might have a feature to save the car battery.

[Rehaan]

Q for B&T: Have the amps been wired directly to the positive of the battery, or do they go through the ELD?

I'd imagine its the former, and therefore....

Originally Posted by Bass&Trouble

By the way, I tested the car for a very long time with the car stationary, and idling, with the aircon and headlights on. This, IMO, is a worse situation than bumper to bumper traffic from a power PoV. But the sound didn't dip even once.

...maybe this behavior makes sense, because the AC and lights are actually putting load on the ELD and therefore its forcing the alternator to charge at a higher rate?


Also, if it is the ELD, then why does the sound only dip for less than a second??

cya
R

[GTO]

Ajay's disconnected the sub-woofer amp (VSL 2500 W rms monoblock). Going to drive to & fro home and update tomorrow morning. This amp is the biggest resource hog...Ajay says it needs as much power as the other two DLS speaker amps combined.

Until then.

P.S. Thanks to all of you for the help. It's been an insightful discussion and one that, I hope, serves as a reference in the future for many other BHPians.

[montyguru]

Originally Posted by GTO

Ajay's disconnected the sub-woofer amp (VSL 2500 W rms monoblock). Going to drive to & fro home and update tomorrow morning. This amp is the biggest resource hog...Ajay says it needs as much power as the other two DLS speaker amps combined.

Until then.

P.S. Thanks to all of you for the help. It's been an insightful discussion and one that, I hope, serves as a reference in the future for many other BHPians.

most interesting. keenly awaiting outcome.

here's one link to bypass the ELD.

http://forum.sounddomain.com/ubbthre...page=0&fpart=3

here's one link for battery.

Amazon.com: Equus 3721 Battery and Charging System Monitor: Automotive: Reviews, Prices & more

[GTO]

*Update*

Nope. Even with the sub-woofer amp disconnected, and only the front + rear speakers working (powered by their two DLS amps), the sound dipped. At one point on the worli seaface, it happened 5 times in as many minutes!

[v&v]

Originally Posted by GTO

*Update*

Nope. Even with the sub-woofer amp disconnected, and only the front + rear speakers working (powered by their two DLS amps), the sound dipped. At one point on the worli seaface, it happened 5 times in as many minutes!

I think here load is not an issue. The source of input ie pre-amp can be culprit. Did you check disconnecting the entire apm system ?

[Invinsible]

This can conclude one thing Civic is not for people who love to enjoy heavy ICE in their car, if one does need should include the cost of other electricals along with the ICE.

ELD is playing the mind games here. I have stated this before too why not disconnect the rear amp too to certain if the single amp works fine. If the problem still persist get the sensor checked will help in knowing all electricals are functioning at it's best.

[navin]

Originally Posted by DerAlte

We should try figuring out whether the ELD + the regulating part in the ECU is doing what it is supposed - jack up the field excitation of the alternator when the voltage dips.

May be the ELD is a bit too sensitive in these load conditions? Maybe there is a loose or oxidized connection?

My assumption untill I read GTO's post below was that the ELD was kicking into low charge mode at say 12.5V while the amps expected a minimum of 12.5V at the battery.

Hence what I assumed was happening was that the battery voltage would drop from say 14V to 12V at which point the ELD would switch to high charge and the battery would recharge to 12.5V at which point the ELD would go back to low charge and the amps would discharge the battery again and the cycle would continue.

Originally Posted by Rehaan

Q for B&T: Have the amps been wired directly to the positive of the battery, or do they go through the ELD?

The asumption we had untill GTO post below -
The amps are wired to the battery and the alternator charges the battery via the ELD. So while the amps are discharging the battery the alternator is unable to charge the battery (fast enough) as the ELD is in low charge mode. Untill the voltage drops to a voltage (assumed as 12V) at which the ELD goes into high charge mode. However the amps expect 12.5V (again assumed) so what is happening is that the ELD charges the battery fast from say 12V to 12.5V then goes to low charge mode. At this point (12.5V) the amps discharge the battery (faster than the battery is being charged) back to 12V where the amps go off and the ELD kicks into high chrage mode again. At high rpms the ELD is not used so there is no such problem.

Originally Posted by GTO

Even with the sub-woofer amp disconnected, and only the front + rear speakers working (powered by their two DLS amps), the sound dipped. At one point on the worli seaface, it happened 5 times in as many minutes!

I talked to GTO during this period and the 2 DLS amps were not even playing at a loud level. I assume that the 2 amps would be drawing more than 5A each from the battery (say a total of 10A). I assume the amps were puting out say 30W rms. To put out 30W rms they would need 60W from the battery. 60W/12V = 5A. Now if the amps were a bit louder and say puting out 40W rms and hence drawing 80W (aka 7A) the battery should still not be affected by a 14A draw.

This same battery tested at 14.3V without load and 14.1V with load. The battery is hence in good condition.

So where do we go from here.

a. One option both Ajay and me agree on is looking at amps that have a very tightly regluated power supply. Such amps are not as sensitive to battery voltage but they are much more expensive (no free lunch). However our object here is to find the source of the problem. If these amps work then atleast we know what the problem is and a workable solution can be found right now all we are going on are assumptions.

b. I know every guru here does not recommend a stiffening capacitor. Still I would say try it. It costs nothing. I too suspect that at best it will reduce the number of dips (fewer charge - dischrge cycles) and not eliminate them. While I have learnt a lot from gurus I can safely say I have lernt more from just doing.

[GTO]

Navin,

- Just like computers have a UPS system, isn't there something similar for car audio? After all, the UPS supplies clean power and protects the computer against voltage fluctuations....just what my car needs!

- Sure, if you want to try a capacitor out, I'm game. Actually, the pro battery guy I went to yesterday recommended the same.