[davidhenderson]

Recently, mid-november 2010, my battery light came on so i drove to advance auto and they said the alternator was dead. i replaced the battery previously in May of 2010 and the car had 144K at that point so i bought one from them and replaced it myself. about a week after installing it my car hardly cranked up one morning so i had the battery tested and although it said it was low and needed to be re-charged it was good (12.63 volts) per advance auto again. they tested the new alternator too at the same time and it checked out well producing 14.35 no load and 14.11 volts loaded. they also ran a test for the drain on the battery and with everything off it showed a 7 amp draw. i had them re-test it 3 days later and it had a 2.36 amp draw. i read on line to check and by putting the pos probe from a multimeter to the positive terminal on the battery and negative to negative to check for AC current which i did and with the car running it read 25.4 volts AC. the site i was on said if it showed any AC current than a bad diode was to blame in the alternator so i took it back and replaced it with a new one that they bench tested before i installed to ensure the diodes were ok in this one. after installing the 2nd alternator i brought it back to have it tested and it showed battery still good but in need of recharge, alternator 14.37 volts, 8.1 amps no load and 14.14 volts, 6.9 amps; .45 amp draw with everything off. thinking i had solved the problem i drove my car on a 400 mile trip to my folks house where it then stayed parked for 36 hrs before it was restarted and it seemed a little weak starting but did ok. the rest of the trip was fine drove 400 miles back home and everything seemed ok other than the occasional weak start on a cold morning until it snowed here and it sat parked for 3 days in the garage with the key in the ignition when i went to restart it again it was hardly able to start. i have gotten a new battery today because the other one from May was finally deemed no good but the computer at Walmart said there had been a significant parasitic drain on the battery.
i came home to check everything out with my multimeter again after getting the new battery in and came up with a drain that ranged from .035 amps with the key out of the ignition to .055 with the key in the ignition (multimeter in 10 amp setting). i don't know why it would make a difference with the key in or out of the ignition as nothing was turned on nor was the key in the ACC position it was just slid into the ignition and repeatedly came up with the same readings.
i then started pulling fuses if i removed #15 from the fuse box under the hood it zeroed out the meter - no draw at all and that fuse is labeled "back up, ACC" otherwise i only saw a .017 difference if the #7 "back up" was removed from inside fuse box or .04 difference if the drivers side pwr window fuse was pulled. all other fuses did nothing with the exception of the radio which was only .01 difference. i would think these draws are normal but am not sure as these fuses control devices with memories?
the thing that seems most unusual is the difference of the draw with the key in or out of the ignition.
i should also mention that i typically drive approx 60 miles a day with probably 8 - 10 starts within that distance (i am a local traveling salesman), i do have days where i drive 150 miles and still start the car approx 8 times.
any thoughts or help would be very appreciated; i feel like i am getting close but would like to be done with this and have solved the problem.

 

[Aviography]

Man that was difficult to read! Please split up the paragraphs.....

Now that I *think* I read it through, I have to ask why you left the key in the ignition?

Finally, 0.035 amp is 35 mA (milli-amp), that is more than acceptable since your radio and fuel control computer requires certain amount of power to keep the memory in them, that's why the fuse you pulled to "zero" the voltage is called "back up" as it backs up the values stored in memory of the radio and fuel control computer.

I don't think you have a problem at this time with a mere 35 mA of current draw.

 

[davidhenderson]

Thank you for your prompt response; i was worried it was too long of a post.
Since I always park my car in my garage my car at night I have gotten in the habit of leaving the key in the ignition out of convenience; no searching for my key in the morning.
Does anyone have an explanation for why the key in the ignition VS being removed would make about a .02 amp draw difference? Again it is not switched on or to ACC position only in the off position within the ignition.
I guess if I need to remove the key and lay it on the dash to avoid additional an additional drain on the battery i could do that but out of curiousity i would like to know why the key in makes a difference.
thanks again for any help you can provide.

 

[PKile]

Honda uses an ignition immobilizer circuit to prevent the car starting if an incorrect key is used. This circuit senses the output of a transmitter in your key when it is inserted in the ignition lock.

My guess is that the immobilizer circuit is energized when the key is inserted in the lock, even before the key is turned to start the car. That would cause the battery drain.

And just an added point - leaving the key in the ignition or on your dash even with the car parked in your garage seems to be a car theft waiting to happen. I put up a key rack in my laundry room right inside the door to the garage, and when I come in the door I always hang my keys up there. Never lost them yet.
Cheers,
Paul

 

[richpor]

Forgetting about your "draw" how old was your battery - if you got 4 -5 years out of it then you are done.... Mine died the same way as what you are explaining... just got weaker and weaker - it's called "reserver capacity" and is diminishes with age on old batteries, I think you just had a old bad battery.

If you had a bad alternator, putting AC into a DC battery, you would probalby have contributed to the demise of the battery..or you just got a bad one to start with, what kind did you get, an Interstate?

 

[Yal]

0.35mA is acceptable draw.

 

[Aviography]

0.35mA is acceptable draw.

I'd like to know how OP could have measured 0.35mA? :dunno:

That's in the micro amp range! :lmao:

 

[SatinSilver]

Man that was difficult to read! Please split up the paragraphs.....

I said forget it after sentence number two. :biggrin:

 

[Yal]

I'd like to know how OP could have measured 0.35mA? :dunno:

That's in the micro amp range! :lmao:

Its a ridiculously small draw for a modern car. But if you have a good multimeter you can read that

 

[Yal]

I'd like to know how OP could have measured 0.35mA? :dunno:

That's in the micro amp range! :lmao:

Its a ridiculously small draw for a modern car. But if you have a good multimeter you can read that I have a Craftsman that has that scale.

 

[EugeneT1979]

Battery Drain

Going to resurrect an old post.

I have a similar situation. I'm on my 2nd battery.
1. 2 new batteries usually reads 12.4 - 12.45 volts when not charging, even if it's only a few hours after driving.
2. Voltage goes up to 14v with car started, drops to 13.7 with engine RPM at 2000 with high beams/lights/AC on.
3. Current draw with everything off is 80mA.
4. If I pull Acc/Back fuse out from under the hood box, draw drops to 0.
5. If i pull a Radio fuse in the driver footwell, draw drops to 30mA.

I'm trying to see if there's a short or a parasitic drain but so far nothing obvious comes to mind. Looks like the alternator is working, voltage is high enough at full load to charge the battery but it's not showing fully charged.

Any ideas?

 

[RickBlaine]

eugenet: You may want to post a new thread instead of adding on to this one as the Original Poster probably turned a lot of people off with his lack of paragraphs....A new thread may attract more people to help rather than read through that first post.

I need Advil.

 

[D-JET]

35 mA is too small. You don't have a parastic draw problem. I would check your charging system and get the battery tested.

 

[RickBlaine]

35 mA is too small. You don't have a parastic draw problem. I would check your charging system and get the battery tested.

My point: the NEW Poster is saying his draw is 80, not 35.

Start a new thread or be punished for the original poster's lack of paragraphs.