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-   -   Flat Battery....1 year old??? (http://www.hotrodders.com/forum/flat-battery-1-year-old-141359.html)

speedydude 07-02-2008 10:31 PM

Flat Battery....1 year old???
 
Here's the current (pun intended) situation. Somehow, gremlins I suppose, leave my ign switch in the "on" position on rare occasions. This will flatten the battery in no time. I have done this around 5-6 times in the last year or so. :spank:

Usually the battery has come right up and been fine. However this time she's a no go. I unhooked the neg cable after driving it to see if I had a parasitic drain. It fired up the next morning. I reconnected the cable and the following morning it was dead.

After reading a post by the brilliant DOCVETTE, I think I may have flattened this battery according to his wisdom. See link...............

http://www.hotrodders.com/forum/68-c...=drain+battery

Also stated in this post is a comment by him that gives a range for proper alternator output. 13.96-14.4. When I checked mine it was putting out 13.34.

Is this acceptable or is the alternator actually going belly up? The bonehead who installed this alternator stripped the lug at the back and this may have been contributing to the problem although it was snug enough, I think, to be charging consistently.

I think the battery is toast and I'll do a load test on it tomorrow. I guess my question is..........is the alternator going??? I tested the current loss between the battery cable and the battery and had just less than 1 amp. .8-.9.

According to the DOC this should be ok but I wonder..............There is NOTHING on and this seems like a bit of a drop. I may pull all the fuses and replace them one at a time as he recommended and see what that yields.

Thanks in advance for any wisdom on this.............JD

T-bucket23 07-02-2008 11:10 PM

that is ok if the battery needs to be charged. Higher current usually means lower voltage. As the battery charges the voltage should go up and the charging current should go down

Chet

speedydude 07-02-2008 11:20 PM

Confused by your answer Chet. If it were charging a low battery, wouldn't the charging voltage would be higher??, say the high end of 13+ volts and maybe come down later. This is at 13.34+/- charging a low &/or flattened battery.

Doc's post leaves me thinking my alternator is on it's way out since it's not at 13.96-14.4. I just thought if I'm gonna pick up a new battery, should I swap out the alternator as well since it may not be up to par???

speedydude 07-03-2008 05:03 PM

1 Attachment(s)
Latest update.............

Checked the battery on a load test.........OK

Had auto parts store check alternator on their equipment............OK
Re-tapped lug for slightly smaller nut............good and tight now!

After 3+ hours under the dash and engine bay, I have disconnected as many circuits as I can find and all fuses one by one with no change. I show a drain on the amp meter of 1.3a, even disconnected the voltage regulator.

I'm pretty stumped at this point. I looked around under the engine and saw that the headers run VERY close to the starter. I have a heat shield installed for the connections to the solenoid but could the heat be affecting anything inside the starter motor itself???? :confused: See attached pic.

Anyone have any ideas??

T-bucket23 07-04-2008 05:49 PM

Quote:

Originally Posted by speedydude
Confused by your answer Chet. If it were charging a low battery, wouldn't the charging voltage would be higher??, say the high end of 13+ volts and maybe come down later. This is at 13.34+/- charging a low &/or flattened battery.

Doc's post leaves me thinking my alternator is on it's way out since it's not at 13.96-14.4. I just thought if I'm gonna pick up a new battery, should I swap out the alternator as well since it may not be up to par???

No the voltage will be lower and the current will be higher. As the battery charges and the current starts to go down the voltage will start to rise. One thing to concider is a lead acid battery does not like to be flattend out. If it goes completly flat a few times it wil never come back all the way. Also if it gets real flat, have it charged, dont depend on your alternator to charge it. You will either shorten the life of the alternator or burn it up. On a flat battery a slow long charge is the best way to charge it, it wont damage the plates by overheating them.
if the battery is junk and the alternator is working constantly to charge is the voltage will be lower. If it is somewhere in the 13's it is probably working.

Try a new battery

Chet

T-bucket23 07-04-2008 05:52 PM

Did you disconnect the Alternator and the Distributor. A 1.3 amp load if fairly substantial.

carsavvycook 07-04-2008 09:45 PM

I have worked on 3 different vehicles that have had between 1.3 to 1.8 volt draws with the key off. All 3 of them would drain a battery over night. All 3 of them also had one thing in common, an aftermarket radio. I tested the 2nd one in a race trailer with a solar panel. The battery was fully charged when I hooked it up, and the next morning it had 5.8 volts. It is still in the trailer. I just have to turn off a switch when I'm not using it. :thumbup:

speedydude 07-05-2008 12:27 PM

Quote:

Originally Posted by T-bucket23
[B][U]No the voltage will be lower and the current will be higher. [/B[/U]]As the battery charges and the current starts to go down the voltage will start to rise. One thing to concider is a lead acid battery does not like to be flattend out. If it goes completly flat a few times it wil never come back all the way.
Chet

You are correct Chet, I had temporary memory loss of Ohm's law.

Deep charged the battery while repairing 5+ very poor wiring connections. NOT from me!!! I think I'll eventually try and scrounge up a good used fuse buss as this one has some real Mickey Mousin goin on. On the bright side it's just the basic original wiring. The only thing added was a radio and a separate horn button. I've disconnected the radio as I never use it.

Alternator is up now at 13.9V and the battery is staying charged well. Not sure where the drain was coming from but apparently it's all good now.

I really miss my Fluke meter,(stolen), as that was perfectly accurate and this Extech one I'm using now is China crap. My 25 year old Amprobe meter gives more accurate readings than the newer Extech. But that's another rant.

Thanks for the replies, this situation at least forced me to redo some of my wiring which I knew really needed to be looked at.

If this particular battery gets flat again, it will be labeled "core". :smash:


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