Please help me diagnose this charging issue

[gsniegow]

Short Question:

When recharging a battery from the alternator, what is the rate / Amps at which it will recharge the battery?  (See long question if this made no sense!)  UPDATE:  Ignore this question as I have since learned that I should not be trying to leverage the alternator to recharge the battery.   


Long Question:

About three months ago I upgraded various components on my electrical system.  I replaced the battery with an Optima Red Top and I replaced the alternator with a PowerMaster 80Amp (one wire).  PowerMaster tests the alternator and states that she should be putting out 68 Amps while idling.  For the last several months this setup has worked brilliantly without any flaws.

About three weeks ago I ran a stereo and amplifier.  Everything has been working wonderfully as well, no charging issues at all.

About a week and a half ago one of my electric fans died.  Those were installed in April along wth an aluminum radiator (not happy with that experience either, but that's another story).  While the fans were functional, they never cooled the radiator off as I would have expected them to.  Anyway, there were never any charging issues at that point either.  I could have the 2 fans on, head lights, radio, and amplifier and everythign worked out great.

After the fan had died a friend of mine offered me his old fan setup to try.  It's a dual 11" Spal fan.  I installed them on Friday night and they worked amazingly, cooling the car down in no time!  I am extremely pleased with the results of the Spal fans!

Saturday I take the car out a couple of times.  Everything seemed fine, but I did NOT capture any readings as all seemed well.  

Sunday I go to start the car and it's dead.  I jump the car and drive it around.  Went to church, came out and it started again with no issues.  With the dead battery in the back of my mind I decided to pull the main fuse from the amplifier as I was suspecting that maybe it was draining the battery.  Then I put her to bed for the day.  

Monday I get home from work and want to see if the battery was dead again or not.  Sure enough, it's dead.  I grab the voltmeter and she reads 5.69 only!  I jump her again and let the car run idling in my driveway.  I measure again and she is reading 12.6 while the car is running.  I believe this to be the juice from the alternator being measured, not the battery.  Car reaches temps and the fans kick on.  I decieded to measure again, and she was now reading only 11.9 with the fans running.  I keep running it and drive it around for a few minutes.  Back home I shut her down and measure again.  With the car not running the battery is reading 11.4 volts.  Car will not start again.  I call it a night as I am using some colorfull language and there are kids outside  playing!  

This morning on the way to work I do another measurement.  She's reading 9.6 now.

Oh, forgot to mention that the fuse for the fans is rated at 30 Amps.

My theory was that while the fans are running, they must be pulling just under 30 Amps to run (as the fuse did not blow).  I don't know how much the battery needs to charge, but if the alternator claims to be putting out 68 Amps at idle, and the fans are using 30 on their own, that only leaves 38 amps left.  I did NOT have the radio, headlights, or anything else on.  To me, 38 Amps should have been enough to charge the battery, which obviously it had as it went from 5.69 to 11.4 in that 30 - 45 minute window.  

BUT shouldn't the volts be in the mid 13's while she is running?  Shouldn't the battery have charged to at least 12.6?

Last night I also pulled the electric from the fans JUST in case I had a draw there.

So even if I had a charging issue, would you expect the battery to slowly drain like that overnight?  In 10 hours the battery went from 11.4 down to 9.6 volts?

Obviously, the delta is the introduction of the Spal fans.  But unless I'm mistaken, things just don't add up.  I could understand if they were pulling 40 or 0 Amps alone, but they must be coming in just nder 30 as the fuse remains intact.  Any and all info would be greatly appreciated!  I'm no mechanic, just trying to take care of my baby and learn along the way.

Apologies for the ignorance, I am learing allot of this as I take this journey.

Thank you in advance!  

- Gene

[resq302]

Well, if you have a stone dead battery, the alternator will give it more charge than a battery that is somewhat low.  It is never a good thing to jump a car with a battery that is that dead otherwise you could chance damaging the alternator from it putting out full current for too long and essentially burn up the alternator.  What is recommended when replacing a battery is to give the battery a full charge on a battery charger and then install the battery.  Do most people do this?  No.  However, most batteries Ive seen, like Interstate, come with at least a minimal 11volts at the battery already which is enough to start a car.

Try charging your battery up over night and with both of the terminals disconnected.  Take a reading when you take the charger off of it.  Write it down.  Check back in an hour or so, write that number down.   Repeat a couple more hours later.  Let the thing sit over night, take another reading.  If you have any significant drop in the battery, chances are the battery is shot with either a warped cell or a cell that is going bad since it is not draining enough from a quick stop and then restart but something that happens over a couple hour time.

If the battery tests out good, I would check the alternators output after the battery has been fully charged and see what output the alternator is putting out.  If that checks out good, I would then try starting the car and taking it out for a drive.  Come back and then disconnect the new fan or anything else new you have put into the car recently and let it sit overnight.  Next day, check the voltage at the battery prior to hooking up the items you disconnected.  If the voltage holds steady at the battery or stays within a volt or so, I would say you found where the problem is with the electrical component.

[Chryco Psycho]

Once you get the battery recharged put a volt meter on the battery with the car running then turn on all the accessories & make sure the running voltage is above 13.6 volts , max approx 14.8 volts , the fans may be drawing enough current that the battery is going dead even when running .If this is the case you will need a higher output alt , like a new Denso type

[gsniegow]

Thank you both!  I guess had I have given my nerves a chance to calm down I would have come to the same conclusion.  Apologies!

I tried to lookup the Denso alternator but was unable to find any for Mopar's.  Is there a part number you could share with me in case I need to upgrade my 3 month old $200 alternator already?   

Will start the testing tonight.

Your help has been very much appreciated! 

[Chryco Psycho]

Mancini has a bolt in denso system I believe . I had a custom alt built for a car I helped build with a serpentine system , it cranked out over 125 amps & would run 2 electric fuel pumps 3 cooling fans , electric water pump , EFI computer + all the regular circuits without killing the battery

[Cooter]

First off, an alternator IS NOT A BATTERY CHARGER....
12.6 is NOT Charging. Anything below 10.5 Volts with ALL excessories on, is NOT good.


You need to recheck charging components and stop using the Alt. as a battery charger. it will NOT last doing that. when you hear that faint "Whine" from it, your killing it.

[gsniegow]

First off, an alternator IS NOT A BATTERY CHARGER....

As I mentioned in my post, I am learning all of this as I go.  I meant not to upset anyone, I just did not know and will not make the mistake again.  Resq302 mentioned it in his response so last night I went out and purchased a proper battery charger and charged the battery over night.  Had I of known, I wouldn't have tried leveraging the alternator in the first place.

Here are the current data points...

* Last night at 8:10pm she was only holding 7.9 volts in the battery (She read 9.6 at 6:30am, so she dropped 1.7 volts in roughly 14 hours)
* I removed the battery cables, hooked up the charger and let it sit overnight
* This morning I took off the charger and she read 13.0 volts.  I noticed that the 13.0 dropped to 12.8 within a minute but I guess that's normal?

She is currently sitting there with no charger on and the battery cables remain off.   When I get home later I will check the charge again.  Hopefully it reads at least what, 12.6 volts?  If not, I guess I need a new battery.  If so, then I will hook the battery cables back up and let her sit overnight to see if she drains at all.

Thanks again all for the guidance.  Hopefully I'll soon know what my culprit is!

[Cooter]

As I mentioned in my post, I am learning all of this as I go.  I meant not to upset anyone, I just did not know and will not make the mistake again. 
* This morning I took off the charger and she read 13.0 volts.  I noticed that the 13.0 dropped to 12.8 within a minute but I guess that's normal?

She is currently sitting there with no charger on and the battery cables remain off.   When I get home later I will check the charge again.  Hopefully it reads at least what, 12.6 volts?  If not, I guess I need a new battery.  If so, then I will hook the battery cables back up and let her sit overnight to see if she drains at all.

Thanks again all for the guidance.  Hopefully I'll soon know what my culprit is!

No harm, wasn't upset, just btrying to keep you from frying your alt. 

Yes, just sitting, the battery will drop a few tenths of a volt, but shouldn't drop to 10.5 running, with all acces. on.
I think you either have an old battery that's on it's way out, or you are experiencing the "Chrysler Alt, blues"...

How old is battery?
What type of Alt/Charging system are you running?

[gsniegow]

Battery was purcahsed this past November, so what, maybe 7 months old?  It's an Optima Red Top battery.

Alternator was purchased and isntalled in the end of March early April time frame.  I went with the PowerMaster 80 alternator.  I had not ever thought of installing a stereo / amp combo in the car but was given the components as gifts.  PowerMaster provides an individually tested result sheet which states it pushs 68 Amps at idle.  I think I may be cutting it close if I had every electrical item on and just sat there idling. 

My two deltas are the introduction of some Spal fans which are far more powerfull then the previous ones and I also bypassed the ballast resistor around the same time.  I can't imagine that is the culprit but when I get home I plan to measure the switched ignition line I ran and see if she is in fact receiving power while the car is off.  Again, I doubt this is the case, but want to rule it out for sure.

[Chryco Psycho]

If you do to a higher output Alt I suggest you should run a bypass wire from the alt output to the battery terminal on the start relay , this will take most of the load off of the bulkhead connector & the Ammeter in the dash as well , Actually I would do this even with the 68 Amp alt , where are the fans connected to ? I assume you are using relays ?

[resq302]

Gene, the battery will drop a few tenths of a volt after you take it off charge and then will possibly drop a couple more tenths as it sits over time.  What I have done to prolong my battery is pick up a battery tender charger and hook it up after everytime I am done taking the charger out for a spin.  Guarantees that I always have  a full charge and never have to worry about over taxing my alt!

[gsniegow]

suggest you should run a bypass wire from the alt output to the battery terminal on the start relay , this will take most of the load off of the bulkhead connector & the Ammeter in the dash as well

Could you elaborate please?  I will also try to research this more.

I assume you are using relays ?

Correct



Data gathered from yesterday's test...

As mentioned before, on Tuesday overnight I disconnected the battery from the car and placed it on a proper battery charger.  I let it charge over night.  Yesterday morning when I left for work it had read 13.0 volts and dropped down to the 12.8 level before I left for work (maybe 30 seconds).

When I returned home from work, maybe 10 hours later, the battery was reading 12.49 volts.  So that's what, roughly 75% charged?  Why would a battery drain so quickly sitting there doing nothing connected to nothing?

I wanted to measure to see if there was any drain, so I attached the postive cable to the positive terminal.  Switched my meter over to measure the amps that were being drawn.  Placed the negative lead to the negative post and the positive lead to the negative battery cable.  It showed zero amp draw.  To make sure I was doing this right I opened the car door and repeated the test.  This time I could see that the lights inside the car were drawing roughly 2.7 Amps.  OK - good I think!  There didn't seem to be any draw.  I took the positive cable back off and rechecked the battery voltage.  It had dropped to 12.42 from conducting that experiment (ran the draw test maybe 4 times to make sure I wasn't screwing up).  At this point I believe my 7 - 8 month old battery is dead.

I take the battery back to AutoZone where I purchased it.  I explained what was going on and they said they would test the battery.  On thier meter it comes in at 12.5 volts.  I'm told that the battery is holding a 80% charge and that it's good.  I argue with them and am then told that a battery with a level of 9.6 volts will start a car and there is no possible way that what I am explaining is correct.  I am told (with attitude) that they have taken advanced automotive electrical engineering courses and I am wrong.  (Am I?)  Anyway - I make enough of a scene where the manager deciedes to just exchange the battery for me.

Take it home and here are my new data points, along with comments / questions...

* Initiial battery level:  12.6 volts

* Car started and running, no accessories: 14.54
* Constant power fuse block:  14.54
* Switched Ignition fuse block:  14.54

FANS KICK ON

* Battery level seconds after they start:  13.2

MAYBE 3 - 5 MINUTES LATER

* Constant power fuse block:  12.5  (Wondering why the difference?)
* Switched Ignition fuse block:  13.14
* Battery level: 13.16

TAKE A VERY SHORT DRIVE THROUGH THE NEIGHBORHOOD

* Battery level: 12.52

PARK CAR AND TURN IT OFF

* Immediate battery level: 12.43
* 5 minutes later: 12.56
* 1 hour later (after last measure): 12.59
* 1 hour later (after last measure): 12.59
* 1 hour later (after last measure): 12.59  (Yes, took measurements every hour for 3 hours)
* This morning, 6:30AM:  12.59

QUESTIONS:
1 - It would seem that the old battery was dead or dying, am I mistaken?
2 - What caused the battery to go from 12.43 when the car was shut off to 12.59 after 5 minutes?  Nothing would be charging it, correct?
3 - Optima literature states that a "fully charged battery should measure 12.8 Volts".  It wass my understanding that a battery is composed of 6 cells each producing 2.1 volts.  ( 6 * 2.1 = 12.6 )   So am I "fully charged" at 12.59 or not?
4 - My understanding of battery levels was...  12.6 = 100%   12.4 = 75%   12.2 = 50%   12.0 = 25%  Is this wrong?
5 - My battery level with the fans running was down to 13.16 (seemed to hold steady there), is that acceptable considering the car and fans are running?

NEXT STEPS:

Tonight, so long as the voltage holds, I will add my stereo and amplifier back into the electrical system.  My radio has a demo feature which is one of my suspected areas of concern.  I will make sure demo is off.  I will run the same test and collect the results.  I will also run a amp draw test again a few minutes after I shut the car down.  Looking to see how much energy is consumed by the stereo & amp combo. 

Thanks again for all the support!

[Chryco Psycho]

I run a 10 Guage wire from the alt ouput around to the start relay Bat terminal , this allows the alt to charge the battery without going through all the connections at the bulkhead , ammeter etc where heat typically is generated & causes failures .
You need more alt output , battery voltage is typically 13.2v @2.2 / cell with the engine running charging it should be over 14 v , usually around 14.2 , running at 13.1 will discharge the battery , this is ok if the voltage immediatly increases with rpm & it is low ONLY at idle speed so by 1500 rpm you should be over 14 v . It seems this is not happening as you returned from you drive with battery voltage @ 12.5 v , less than you started with !
So you have 2 choices , return to a clutch fan for cooling & lose the electric fans or increase the alt output to a newer Denso type alt putting out 100+ amps & more amps at idle . Electric fans are less efficient than clutch type & draw a lot of power .