Grand daughters car battery

37chief · Dec 25, 2014

Last week I posted a problem my grand daughter had with her 3 month old battery going dead after a few days. I had the battery checked it is good. the alternator is ok. I charged the battery. I removed the ground, and have 6 ma between the post, and the ground cable. in a few seconds it drops to 4 ma. Then I notice the meter droops to .5 ma. Does this sound like it is working ok? This is a 02 Honda. Problem is, I don't know what made the battery go dead in the first place.Stan

Janicholson · Dec 25, 2014

That is not an excessive draw. 200ma is one tenth amp. Tt should go weeks even with that much draw. Maybe something like a light was left on, or the brake light switch kept the brake lights on. Jim

david - or · Dec 26, 2014

200ma is 2 tenths of an amp, not 1 tenth, and a car with this draw and a typical 125RC starting battery, parked when fully charged, will be down to 10.5 volts in about 10 days. At that point it is considered fully discharged and may not start the car.

Automakers strive for the standby current (called IOD or ignition off draw) to be 50 ma or less.

This allows about a month of standby time.

A draw of 6 ma or less is well within this spec, and is so low as to call the accuracy of the measurements into question. If it really is 6 ma this is not the source of the grand daughters no-start problem.

One possible diagnostic test is to remove the battery cable overnight. The next day, re-install the cable and again try to start the car. If it starts, the car has excessive standby loss. If it does not start, the battery is bad (perhaps with an internal short that doesn't show up on a simple load test).

Fatamus · Dec 26, 2014

(quoted from post at 00:00:22 12/26/14) 200ma is 2 tenths of an amp, not 1 tenth, and a car with this draw and a typical 125RC starting battery, parked when fully charged, will be down to 10.5 volts in about 10 days. At that point it is considered fully discharged and may not start the car.

Automakers strive for the standby current (called IOD or ignition off draw) to be 50 ma or less.

This allows about a month of standby time.

A draw of 6 ma or less is well within this spec, and is so low as to call the accuracy of the measurements into question. If it really is 6 ma this is not the source of the grand daughters no-start problem.

One possible diagnostic test is to remove the battery cable overnight. The next day, re-install the cable and again try to start the car. If it starts, the car has excessive standby loss. If it does not start, the battery is bad (perhaps with an internal short that doesn't show up on a simple load test).

Yup that will do it.
Good luck.

MarkB_MI · Dec 26, 2014

I wouldn't be concerned at all about a draw of less than 10 mA.

Some thoughts:

It could be the condition drawing down the battery is intermittent. For example, a trunk light or brake light switch.

Is there any aftermarket equipment in the car? Remote starter, aftermarket stereo, etc.? Try disconnecting anything that's not original.

The battery could be bad, even if it passes a load test. Only way to know is to disconnect it for a few days and see if it discharges.

The alternator might not be fully charging the battery. Check the battery voltage while the engine is running after the car has been running for a while. Anything less than 13.8 volts I'd be worried about.

JDJACK · Dec 26, 2014

I agree 6 ma seems low.
You want to hook the meter up in series, with the negative cable still hooked up and let sit for 30 minutes, and then disconnect neg cable, (make sure that that neg side has never broken a connection) with meter still in series, reading the draw.
I have a tool that I used for this, when I worked at the dealer. Excellent tool and cheap to make.
Helps saves on the meter fuses also.

RickieBlue · Dec 26, 2014

I agree totally with jdjack. I have see alternator diodes that are functioning as they should while charging, once the charging goes away, they will be show signs of being shorted and draw some amperage. Once the battery is disconnected, and reconnected, it will be OK. Often times with diodes that perform like this, while charging they will show above normal AC voltage above the allowable reading of .5 volts. This is best checked at the alternator.

ASEguy · Dec 26, 2014

Yes that sounds ok. As controllers go to sleep the current flow will decrease. How old is the battery? Age doesn't necessarily determine when a battery goes bad, but in my experience most conventional lead acid batteries won't go past four or five years reliably. Date codes are usually branded into the plastic or they will have a sticker on the battery. Hope this helps.

Geo-TH,In · Dec 26, 2014

Stan, Something isn't adding up. A good battery can't go dead in a few days.

Is the car being driven in those few days? If so, then the alternator isn't doing it's job, or there is a drain larger than .5ma = .0005amps.

Who told you the battery was goo? Who told you the alternator was good? Like I said, something isn't adding up.
george

El Toro · Dec 26, 2014

My neighbor was having that problem on a big Ford car. She said they checked the alternator and battery at a battery warehouse and told her both were ok. They told her to take the car to a Ford
dealer. She called the dealer and they told her it would cost $100.00 just to check it. I took some beets and green beans over to her and took along my multimeter and had her to start the car.
I was only getting 12 volts and told her either the alternator is defective or you have a broken
belt. The belt was ok. I told her the meter should have a reading of 14 to 14.5 volts.

She had a local shop to install a rebuilt alternator. Hal

El Toro · Dec 26, 2014

Charge that battery and use a hydrometer to check the specific gravity in each battery cell and post the readings. Hal

RayP(MI) · Dec 26, 2014

We had a problem years back... Ford Bronco II. Wife would drive to work, only to find battery dead at end of shift - SOMETIMES. Spent a lot of time trying to figure that one out. Had alternator rebuilt, and there in lay the problem. Defective controller in alternator. Rebuilder had several defective ones (new). Here's what was happening... when wife would shut down car, go around to passenge's side, open door to get purse & lunch bag, sensing circuit would sense voltage drop due to dome light, and trigger alternator - energizing field coil, discharging battery. Short stops were no problem but after a 8 hour shift...
Only happened if passenger door opened after car shut down. Finally took alternator back to rebuilder, found origional regulator in junk pail,reinstalled, and problem went away. He had several bad brand new regulators in stock. So replacing with new wasn't solving the problem.

Dennis (VA) · Dec 26, 2014

It's only three months old. take it back.

JRSutton · Dec 26, 2014

maybe I missed this - but you said the alternator is ok... how do you know that?

I've had an alternator test fine at the local car parts place, but replaced it anyways as a last resort - and had my problems disappear.

So - just saying - I wouldn't fully trust a parts store test. And for the price of most alternators these days, personally I'd probably just swap it out if it's easy to get to. In a case like that I figure they don't last forever, so why not - if it fixes your problem you win, if not, you've at least delayed the inevitable replacement of it, for not that much money relatively speaking.

David G · Dec 26, 2014

Make sure she is not leaving the dome light on.

37chief · Dec 26, 2014

I took the battery to a battery shop, they checked each cell with a hydrometer. when the battery was dead, and jumped after running for around a hour, the battery started the car with no problem. Stan

gfj · Dec 26, 2014

Have you tried putting battery in another car to see if it does the same thing?

bobs old iron · Dec 26, 2014

couple of old school ideas,, did you/she put in after markets items in, radio-alarms-etc,, after a few days they draw juice off batt,,,or disco pos batt end, hook meter up between post-end, start pulling fueses and watch meter,, now if this able to be done on newer cars,,like i said, i think old school sometimes...

Goose · Dec 26, 2014

Probably no connection. but several years ago one of my wife's brothers brought me a Chevy full sized conversion van that was doing the same thing.

I went nuts going though all the conversion wiring, etc. Finally when I was poking around on the wiring under the hood, I noticed the wire was unplugged from the horn. I touched the wire to the horn and the horn blasted me.

My BIL would never admit that he did it, but the horn button in the steering wheel had broken, leaving the horn on all the time. Pulling the wire from the horn shut the horn up, but the horn relay stayed energized. And that was enough to run the battery down in a few days.

Fixing the horn button fixed the problem. I said afterwards that it must be a heck of a healthy horn relay to stay energized that long.

Janicholson · Dec 26, 2014

Late at night and my bad math. Still a good idea at .2 amps. Jim

Geo-TH,In · Dec 26, 2014

Stan, If problem doesn't go away, I would take to an auto store and have them test it with a battery conductivity tester. I have hydrometer, old school load tester and new school conductivity tester. I no longer use hydrometer. Gave my load tester to my BIL. The conductivity tester is the only way to go. Just my opinion. I just had a 5 year old marine battery die. It has been on life support for the past year or so. Yesterday the Conductivity tester said bad battery, DEAD CELL.

Also most auto stores can check alternator for you.

Is it possible that alternator and battery are good and while it's running there is too large of a load, like a very loud stereo amp?
George

IH2444 · Dec 26, 2014

One cell in the battery might have an internal short and is going dead, that would leave you about 10 volts or so.

IHC Red · Dec 26, 2014

I think 0.2 mA sounds about right. There could be a dash/interior light or something which shuts off after a minute.

I had a problem like you describe on a car which wasn't used much at the time. It killed a new battery quickly. To this day I'm not sure if it was a sticky relay, a bad battery, or a fluke, but it hasn't happened since.

JDJACK · Dec 26, 2014

The battery can be and should be tested with a good tester, not the fluid type, we had a very good one at the dealership. Just a small electronic tester, could tell if had a shorted cell or need to be charged or just a bad battery.
He is what I would do. Disconnect the cables from the Battery, test with (dvom) digital volt meter. if not 12.6 volts charge for 12 hours. then test again after charger is off. Let battery sit, do not hook up to car. come back in 6 hours should still be at 12.6 volts.

Hook to car, start car, with dvom hook up car running turn fan on high rear defroster on , wipers headlamps. read voltage should be around 13.5 volts if not alt might be getting weak.
If good there is probably a draw on system.
This is something that can be figured out in 1 hour.
Post a contact # if you need help.

Grand daughters car battery

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