[montyguru]

something like this was used by the batt guy and showed one cell at fault which is why current dropped erratically.

eBay India: 12V LEAD ACID BATTERY TESTER CHECKER INVERTER CAR SOLAR (item 150500636602 end time 29-Nov-2010 20:21:02 IST)

[Invinsible]

Originally Posted by montyguru

i'd recommend getting each cell individually checked from a battery wala... they measure it with a device and you get to know if there is even a single weak link. was having a similar problem with baleno, batt used to be fully charged but once in a while, car didn't crank up... it's hard to detect, coz normal checks always show full charge and charging voltage is also correct. one cell was kaput causing erratic voltage drops... once in a while.

Originally Posted by Bass&Trouble

GTO's system doesn't need THAT kind of power. Its overkill. It'll also result in lesser mileage and power besides everything else.

If a cell from the battery would have gone kaput, it would have resulted in the battery drain out at the end of the day. The battery would have got drained with just the AC being on in the day time, leave apart running those amps would have made the battery completely dead. When a cell go weak or dead it is still managable to start the car by push or jumps start, once the car is started everything runs fine thats because the alternator is doing the job of keeping the battery charged to some extent in other words suppling the current the battery requires. But when the car stalls, the car won't start thats when coz of the weaker cell the battery is not able to supply full load that is required for the car to start. If one of the cell of the battery in GTO's car had gone kaput this would have been one of the scenario he would have been facing. However there's no harm in finding out if all cell in the battery are working at it's best.

Here is my understanding to the problem, the ELD is connected or falls between the battery and ECM. It signals the ECM how much power is required and in return ECM signals back how much power should be supplied. GTO has connected the amps directly to the Battery, in which case the ELD senses the battery power is being wasted and puts it the safe mode at the ideal by drop in voltage which means keeping the battery power safe incase to feed in enough to other components.

I suspect none the battery and the alternator have gone kaput but yes I am guessing they have definitely gone weak by time after adding those amps and their usage.
The other possibility I think could be where the ELD and the ECM together (after adding the amps) detects that both the battery and alternator is working hard in trying to keep up with the power output that is required but puts out into protect mode at ideal after the car warms up that's because when the battery and alternator is at rest since more than couple hours the voltage output is wee bit more compared to what it is once its working and warms up, where there is bit drop in voltage. No wonder GTO is not facing the drop in sound at the start of the car and only when the car warms up one sees a drop.

This issue wouldn't have been in the first two months of using those amps but everyday usage and in trying to keep up with the power/current required, the battery - alternator could have gone weak.

The solution I could think of is to get the battery completed charged at some battery station, after putting it back after the charge, determine the time duration it takes before dropping the voltage. If the time is somewhere close to earlier one and is not much longer this time, than I suspect it's the alternator that has gone weak.

Putting the bigger alternator will make things easier for the battery where ELD will not suspect where the additional current is going. Bigger alternator will keep charge at the optimum, ELD will sense the components that needs power/current are getting at it's best which could be including the amplifiers. In the current state (with the amps) power drawn from the battery is higher and the alternator is not able to keep up in charging the battery in the required stipulated time. A bigger alternator will do that more efficiently thus making the ELD believe that the power is not being wasted or leaking anywhere and avoid going into the protect mode or dropping the voltage. At idle the stock alternator is not enough to keep up with the charge that the battery is throwing which makes the ELD sense the issue and drops the voltage at idle. The stock alternator puts out its rated ampere or charge at higher RPM around 2,500/3,000 rpm in which case the battery is keeping up with the required charge it needs thus enabling all the 3 amplifier work fine when the car is running. High output alternator will do just that at idle since their rated amps is 80 at the idle and that's equivalent to what the stock alternator does while the car is running.

Originally Posted by navin

No GTO this would be a last resrot solution. I'd not advise messing with the ECU and it's associated components unless we have a Honda expert on board.

I agree there are many more options that are available that could solve the issue here before investing into it.

Originally Posted by navin

Superb Idea. Ajay proposed this to me yesterday too. My suggestion was more efficient speakers but that would mean that GTO would have to tune his set up all over again.

I would just switch the Subwoofer amp to class D first. If that works then whny change all the other amps.

Getting all full range class D amps would be better proposition while keeping the speakers. JL HD are surely one of the best SQ class D amps out there, it's Class D with regulated power supply plus it would match up with the music requirement, DISCO on wheels
The other that would work fine would will be the ones with regulated power supply like the JL Slash series. The other choice could be the Infinity kappa 4 and kappa one available locally.

Originally Posted by navin

However a simple check to ascertain if this would work is to simple disconnect 1 of the 2 DLS amps that feeds the rear speakers. I think Vanhallen suggested this in an earlier post.

GTO can you live with a front speaker+subwoofer solution for a week?

Why not disconnect both the rear and sub amp and run just the front to see if the problem still persist. May be running for a day should give an idea.

[Mpower]

Originally Posted by GTO

What's the way ahead?

• Get an Amaron yellow top battery (D55 / D34). Link. Is a high aH rating battery the solution?
• Upgrade the "Big 3 cables"? Some already done to my car at the time of install, others not required.
• Lower the amp gain level? Still not the real solution though, I love the sound the way it is.
• Install capacitors?

Thanks for the help!

Assuming your alternator and battery are sound, you're not getting enough juice due to the heavy electrical load. There is a product called overdrive pulley which spins the alternator faster during b2b crawl. Check this out, NST 21922

NST - The Leader In 8th Gen Civic Pulleys

[montyguru]

Originally Posted by Invinsible

If a cell from the battery would have gone kaput, it would have resulted in the battery drain out at the end of the day.

i faced no such problem. once in 7 days, the car refused to crank. the batt never drained out, it never even showed a voltage drop. i paid 3 trips - one regular check, one getting the batt fully charged... on the 3rd we checked each cell and found the problem.

Originally Posted by Invinsible

Putting the bigger alternator will make things easier for the battery where ELD will not suspect where the additional current is going.

this may not work as current is not going direct from alternator to battery. the ELD has a shunt mechanism with resistors. it measures batt voltage, volt reqd and automatically reduces the alternator load. for some ppl, simple things like switching on headlights or keeping power window switch constantly on has worked as it misguides ELD and generates more current.

it's all explained very well here -
http://forum.sounddomain.com/ubbthre...page=0&fpart=1

[navin]

Originally Posted by low_bass_makker

220 amp output -Full output by 1800 rpm engine speed
-Excellent output at idle, 125 amps by 800 rpm engine speed !!

Originally Posted by Bass&Trouble

GTO's system doesn't need THAT kind of power. I'd suggest to put all alternate solutions on hold till you get the new battery. We can decide on the course of action after seeing how the system reacts to this change.

The Class D amps you suggested will help.

Originally Posted by valhallen.282

Old knowledge: try everything that does not require you to change anything first. Then change one thing at a time. That's when you know if THAT particular change made any impact.

which is why I like your suggestion of disconnecting one amplifer (I'd say one of the DLS) and also suggested the capacitor (though I am doubtful it will help atleast the voltmeter on the cap can give you readings, obviously this means someone has to observe the capacitor when teh dips happen).

Originally Posted by greenhorn

If it were me, if a new battery doesnt improve matters, I'd make sure that this really is the ELD kicking in before trying out any surgery,

1. I do not like messing with the ECU of modern cars unless there is someone who knows exactly what he/she is doing. The ELD probably gets in's input from the ECU.

2. If it indeed the ELD (I think Greenhorn has the modus operandi of the ELD right) then the easiest way is to increase the efficiency of teh system by either using more efficient amplifiers or speakers or both.

[DerAlte]

Originally Posted by navin

... The ELD probably gets in's input from the ECU. ...

The ELD (the passive components in the fuse box) give input to the ECU, which changes field current of the alternator based on load profile.

[NetfreakBombay]

How does it changes field current of alternator?

I assume that would be done by increasing engine RPM, is that correct?

[low_bass_makker]

Originally Posted by NetfreakBombay

How does it changes field current of alternator?

I assume that would be done by increasing engine RPM, is that correct?

By changing the rotor excitation voltage. Actually the voltage is controlled not the current. If the voltage is reduced to 12.8 from 14.4 then there will be no current.

[navin]

Originally Posted by low_bass_makker

By changing the rotor excitation voltage. Actually the voltage is controlled not the current. If the voltage is reduced to 12.8 from 14.4 then there will be no current.

Exactly

Originally Posted by montyguru

this may not work as current is not going direct from alternator to battery. the ELD has a shunt mechanism with resistors. it measures batt voltage, volt reqd and automatically reduces the alternator load.

The question then is why, when the load increases, does the power dip and amps go off. If your hypothesis was true when the load increased the ELD would have allowed the alternator to charge the battery faster.

I suspect the ELD limits the current the alternator provides to the battery hence when the load inceases the battery is discharging faster than it is charging and at some point it's voltage drops below a threshold required for the amps. The amps then go off and a second later when the battery has regained charge the amps work again only to discharge the battery again and the cycle repeats which is why GTO's car faces the dipping about 20 times per trip.

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.

If the alternator was able to charge the battery at a rate that was faster than the rate at which the amps are discharging the battery there would be no issue.

This can happen only if the alternator puts out more current during idling (than it is doing now).

Originally Posted by Mpower

Assuming your alternator and battery are sound, you're not getting enough juice due to the heavy electrical load. There is a product called overdrive pulley which spins the alternator faster during b2b crawl. Check this out, NST 21922

NST - The Leader In 8th Gen Civic Pulleys

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.

Hence there are 3 options.

a. we mess with the ELD and change the resistor values to increase charging rate marginally.
b. We replace amps/speakers to produce more Acoustic Watts for every Electrical Watt consumed
c. We install a rectifier-regulator circuit at the alternator end (Charging System Basics) and tap the voltage from the alternator directly OR install a second battery AND dual battery isolator (so one battery does not attempt the charge the other).

Of the 3 options I believe option a might reduce the reliability of the car (GTO already has one play car), option c is expensive and complicated altheough in the days pre Class D amplification I have installed dual battery isoaltors for 1-2KW installs and before these myths were busted (http://www.caraudiobook.com/car_audi...udio_myths.htm). Option b (which was propposed by B&T and others) seems the most sensible option.

To test this hypothesis all GTO needs to do is disconnect one amp (I would recommend the rear channel amp) and live with the "correct" soundstage for live music (front only - no rear fill) for a few days. It does not cost a penny.

GTo please understand this..
a. 12V x 50amps = 600W, if you had a 70A alternator it would be 12x70=840W. If your stereo is drawing an average power of say 500W (assuming 50% of the max total of 1000W rms) it leave precious little for the rest of the accessories (air-con, lights, etc..). Upgrading to a 150A alternator or installing 2 70A alternators would have worked if not the for ELD which will limit the current from any alternator not knowing that the alternator is now a superior one than the one it was programmed for.

b. All batteries have a max charging current. Upgradig the alternator without taking this into account can limit the life of the battery. Hence what we used to do in the old days is upgrade the alternator AND install a dual battery and control/isolation circuit to limit charging current to safe limits of the battery. I hoped that Class D amplifcation would eliminate all this.

c. Adding a capacitor might not help (as Gurus like B&T and Sam Kapasi have testified) but it costs nothing (if B&T has a loner cap available - I have a 0.5F cap if you need it installed in my FIL's car) and is a 10 minute install/uninstall. And by chance if it does help ....LOL.....hey what works, works na?

[valhallen.282]

GTO sir need to know if anything apart from the dyno trip happened this weekend. Else this thread will continue in speculation and will cause anyone else who has this problem to scratch their head too much.

Navin sir I still think just one sub and the front stage will be needed to see or feel the difference. The twin subs are more sustained load than just the rear fill. So removing rear fill won't make THAT big a difference but removing a sub will.

[navin]

Originally Posted by valhallen.282

So removing rear fill won't make THAT big a difference but removing a sub will.

I agree but I believe the difference between the charging and discharging currents is small and just one amp being left out of the circuit should help.

[montyguru]

Originally Posted by navin

Exactly The question then is why, when the load increases, does the power dip and amps go off. If your hypothesis was true when the load increased the ELD would have allowed the alternator to charge the battery faster.

navin, i personally think this is a battery problem.. one of the cells has gone weak causing erratic drops.
secondly, amp load is direct through battery. the ELD does not know, it has a simple funda.. when batt is 12.5v, it reduces alternator to produce 12.5v.

Originally Posted by navin

I suspect the ELD limits the current the alternator provides to the battery hence when the load inceases the battery is discharging faster than it is charging and at some point it's voltage drops below a threshold required for the amps. The amps then go off and a second later when the battery has regained charge the amps work again only to discharge the battery again and the cycle repeats which is why GTO's car faces the dipping about 20 times per trip.

bingo. this is exactly what's happening. however, this doesn't happen with headlights - and neither in starting the car... so somewhere this sudden drop has to have a reason... even if battery has 12v charge, this should not happen! the batt has enough power to start the car... then why the drop? audio surely is not taking so much out of it.

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.

ELD installed only for mileage/emissions. i wasn't aware civic has it. in the accord, the ELD is programmed to switch off or reduce alternator draw mostly at idle and cruising speeds to increase fuel efficiency. it kicks in at high RPMs when car has extra power to charge. when voltage drops below the required level, it kicks in even at idle and increases idle RPM slightly. cannot quote - but was lucky to work on new accord n paid a factory visit to HSCI ;-)

changing the amps might solve the problem temporarily. i would not recommend doing anything till first the batt is thoroughly checked - if possible a new battery tried. if the problem persists, yes, class D amps can be a solution. or an ELD bypass with toggle switch. or others.

[navin]

Originally Posted by montyguru

navin, i personally think this is a battery problem.. one of the cells has gone weak causing erratic drops.
secondly, amp load is direct through battery. the ELD does not know, it has a simple funda.. when batt is 12.5v, it reduces alternator to produce 12.5v.

an ELD bypass with toggle switch. or others.

1. If the battery is weak can it still provide the cranking amps to start the car? I assumed that the battery is stressed out most when cranking. One can still test this hypothesis out...run the audio system for 15-20 minutes without starting the car. Now switch the audio system off and crank. If it cranks then the battery should be fine na? I'd keep a set of jumper cable handy though.

2. If the ELD increases the charge to the battery once the voltage drops below 12.5V should it not allow the alternator to charge the battery faster when the voltage drops below 12.5V? In which case all we need to do is ensure the amps are designed to operate at 12.5V and not just 13V+. Almost all Class D amps are.

3. If the ELD is just a series of feedback resistors with no connection to the ECU why not trick the ELD into charging the alternator at 12V instead of 12.5V? It is a simpler, neater solution with just a resistor change required.

I spoke to GTO and he is keen to get a new battery because his old battery is 42 months old and nearing the end of the life of a OEM battery. Fair enough but why not really see if the battery is indeed faulty.

[GTO]

*UPDATE*

Electricals thoroughly checked (with engine off, and while idling) by a reputed battery shop.

- Battery OK. Termed as "healthy" by a pro battery chap. Even though I was willing to buy a new battery from him, he (honestly) told me that I don't need one.

- Alternator OK. Charging varies around the 14.xx level (between 14.1 - 14.3).

- Electrical system OK.

Now what?

[Invinsible]

Originally Posted by GTO

*UPDATE*

Electricals thoroughly checked (with engine off, and while idling) by a reputed battery shop.

- Battery OK. Termed as "healthy" by a pro battery chap. Even though I was willing to buy a new battery from him, he (honestly) told me that I don't need one.

- Alternator OK. Charging varies around the 14.xx level (between 14.1 - 14.3).

- Electrical system OK.

Now what?

Why not check the charging when amps goes off ? This will help in indicate the further possibilities. Run all 3 amps and when the amps goes off get the voltage checked.

So we save here on the battery part. That's good.