Battery drain - illogical behavior

My 1995 Maxima is draining the battery. Driving it charges the battery somewhat but after parking for a few hours or overnight the battery is very weak. So far I tried this:

- Brand new battery: same behavior within a week.

- Starter is OK, about 1/2 the time it starts right away, other times it takes longer.

- Measured 110 milliamp draw between the negative terminal and its cable with car turned off, keys out [in my pocket]. The book says it should be ~50 milliamps max.

- Measured 350 milliamp draw between the positive terminal and its cable with car turned off. I know it seems to defy physics but I measured this repeatedly with the same voltmeter.

- Pulled out each fuse in turn. One of them dropped the draw from 110 to

  1. The rest made no difference at all.

- Had the car at a reputable shop for a week. They worked on it ~ 8/9 hours, checked plenty of things, could not find the problem. They truly are professional, charged me for only 2 hours and put in much more + asked their friends' opinion.

- Even when the battery is weak starting the car, all other electrical things work fine: lights, power windows, radio, etc.

- Battery voltage = 12.5V with key off. Starting the car shows ~14V to

14.5V i.e. the alternator seems to be doing its job.

I hope someone had the same symptom and can share the root cause(s) with me. At the very least, offer ideas who are the primary suspect systems? It seems to be some circuit that's not going through a fuse and stays connected even when the key is out. Any advice is thoroughly appreciated.

Regards GS

Reply to
Gershon Shamay
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That kind of drain isn't going to kill the battery is a few hours or even overnight.

Have you tested the alternator with a full load on it or done an amp test?

Has the alternator ever been replaced?

Reply to
Steve T

I agree with your comment about defying physics. A couple of questions: Positive or negative earth? How is the starter motor cable included in your testing method? Stupid question: is there a centretap cable connected to the battery or is there another cable present of which you have not measured the current? Did you change test-meter current ranges between the positive and negative?

Reply to
jim

"seems to defy physics but I measured this repeatedly with the same voltmeter·"

- with clean connectors, measurments should be equal. Clean, Use dielectric grease. (See p.14)

- the issue is leaking alternator rectifier diodes. Disconnect alt charge connector [2.] at positive pole to verify. (see pic below, web page5)

- I replaced the diode bridge and regulator/brush assy. This dropped the drain from 1.25A to 0.15A. Note: after one day stay, everything else is cold except alternator, alt casing warmth may be felt by hand with 1.25A leak.

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It is a problem as I dont use the max daily. Short drives, cold weather means high consumption; needs extra charging. Cold battery intake below freezing point is poor.

Your .35A consumption should be ok IF:

- charge is ok,

- battery warms up,

- driving times exceed 30min with 2000rpm or over.

- weather is above freezing

- Below that, using multiple appliances and frozen batt will cause drain...

A writeup can be accessed at

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Calculating: The reference to amps is per one hour...

  1. Thus your daily system drain is 24x0.35A=8.4A
  2. Battery is
60A -BUT- cold subzero weather 'reduces' it to 25A
  1. Cold subzero weather reduces its recharge capacity to 5A
  2. Each startup takes 2A-10A depending on start lenght

Summing down: 25A minus one day sitting (8.4A) leaves 16.6A for cold startup. Bad start, minus 10A to 6.6A. Half hour drive charges battery with

2.5A. Day ends with 8.5A. Day three: One day sitting (minus 8.5A) and even leds will not blink...

Depending mileage I'd repair your alt (after harness cleanup; read pages 14 and 10).

What I am still planning to do, is to add a double relay to cutoff my 0.15A alt leakage (when engine is off). Without alt, the drain will be near zero e.g. below 0.01A

If u need hlp, e-mail me, address is on page1

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Reply to
Wiikinki

Hi,

Here's a problem I had a couple of years back, and posted the foolowing to this newsgroup. help you.

93 GXE 140k miles

Had nearly 30 days of continuous below-freezing weather where I am, Washington DC suburb. Drove one to local mall a few miles away. Came out after about two hours, battery is completely flat, will not turn engine over. I figured it was the cold weather, many cold starts, heater running constantly, often using headlights, short, start/stop runs.

Called my wife, she brought her car with jumper leads, started OK. Drove the car home and put the battery (only 18 months old) on the charger overnight. Reconnected it next morning, car starts and runs fine. Assumed the problem was solved. Next day I get a call from my wife, Maxima has flat battery outside local library.

Same procedure, jump start then drive home. Took the battery out and put it back on the charger. Left the car till the weekend for further examination.

On the weekend, looked up my Haynes manual. Started doing their charging system checks.

1) All fuses inside car OK 2) All relays under hood OK] 3) Battery open voltage OK 4) Put an ammeter in circuit with the battery (disconnect negative battery terminal and insert ammeter) Found that with the IGNITION OFF there was a 100 milliamp current drain. Haynes says the maximum current drain (considering, clock, radio presets, engine control computer, etc) should be 50 milliamps.

With the ammeter still in circuit I started pulling connectors off the positive battery terminal. As soon as I removed the fuseable link which connects to the alternator main terminal, the current drain dropped to zero.

Remembered Nissan Tech and possibly others had previously mentioned the alternator diodes go bad after time, so I figued I had found the problem.

Bought a new alternator my local Nissan dealer $368.00. Replaced the alternater, recharged the battery. Problem solved.

From a recent post to this newsgroup it appears that you can in fact repair the alternator, but I have I can't find the article, it was on cardomain.com I believe.

Al Moodie.

Reply to
Al Moodie

Probably leaky diodes in the alternator. The current drawn will vary tremendously with temperature. You'll have to disconnect the alternator while measuring the current drawn to see if it drops.

Reply to
SteveB

I think the only thing that typically does not go through a fuse or link is the fat lead to the starter. That is supposed to be switched through the solenoid on top of the starter, but perhaps you have some leakage there. Even 350 mA drawn overnight should not appreciably drain your battery to the point where you have a hard time starting.

Could it be that your battery or current drain is not really at fault? With a multimeter across the battery, does the voltage drop a lot when you are starting? I wonder if the starter or connections to the starter are good. Next time you are having a hard time starting, hook the negative side of your booster cable to the battery negative and the other side of the cable to a beefy part of the engine. (don't use the positive lead - just let it dangle). See if this helps your issue - if it does, you have a bad ground connection somewhere (battery/frame, frame/engine, engine/starter)

Remco

Reply to
Remco

Thanks, guys, for all the good advice so far. A few points:

- I live in South California, cold weather is not a problem.

- Turning lights on after start drops the voltage just a little bit, ~0.1V.

- This happened > Gersh> > My 1995 Maxima is draining the battery. Driving it charges the battery

Reply to
Gershon

Now this *really* sounds like a flaky starter. When you tried to start, was the starter turning the engine normally (as best you could tell)? If yes, then there was something wrong with your fuel/spark/compression triad. If no... sure sounds like a bad starter.

Maybe you have 2 problems: 1) starter going bad and 2) a slight extra drain on the battery?

Reply to
R Flowers

Had same peoblem with '92 max gxe, tried all, finally removed cig lighter all fine since. Great car have 224,000 miles and never anything cept usual maint. original alt. and all.

Reply to
jimmijoe

Thanks to all the advice, guys. I thought the group deserves to know what the problem was - after all you took the time to read and post. After a lot of work ( ~15 hours of labor) and pretty much taking the entire electrical system apart, my local repair shop traced the problem to a defective driver's side door lock master switch. That switch conspired with the theft alarm system [built in the Maxima] to keep pulling power, thus draining the battery. These items don't go through the ignition switch nor through fuses, obviously they have to operate even if a fuse is blown and the car is locked. Which is why the battery kept draining while parked.

My hat is off to this repair shop. Worked on it ~ 15 hours but charged me for only 5. Beyond that it was personal, their own professional pride took over in the battle against this problem. I know someone may say "real pros would have found this in 1/2 hour". I doubt it. Maybe if you had this exact problem previously, you would try it first but otherwise you would go after the usual suspects, like the rest of you suggested.

If you live >Had same peoblem with '92 max gxe, tried all, finally removed cig

Reply to
Gershon Shamay

Thanks for posting the problem, very few people give back to these forums..

Reply to
Steve T

Steve T cried out

I would have never guessed that.... Kudos to the repair shop!

Reply to
Rosco

Once you find a good repair shop, stick with 'em. My hats off to your Orange county mechanics. And I do understand that electrical problems can be very very complicated and take a while to figure out.

Glad to hear things worked out.

CD

Reply to
Codifus

I was just about to post to check the theft system. its the one system that can both cause extra battery drain and randomly prevent starting.

The theft system uses a fuse like every other vehicle system. Security does not trump safety.

Yea, keep those guys. If they can solve electrical problems, you want to keep them. Also follow that mechanic.

Reply to
dnoyeB

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