a short, the alternator, battery or starter solenoid???

[remigio]

vehicle: 86 3.2L 911.

symptom: having had to start the car daily and run the engine for ten minutes or so to maintain charge to start the car; otherwise the battery goes dead. quick jump from our other vehicle will start the car (INSTANTANEOUSLY, no hesitation, no cranking/growling sound) and is good to go --unless i fail to run the engine daily.

background: this battery came with the car which was bought jul 2010. battery went flat and was fully recharged three months ago; the car started fine since but the symptom is back for a couple of weeks now.

i put less than 200 miles a month on the car. i want to just hook it up to a battery tender.

comments/advice

[Jdub]

The amount of charge you take by starting cannot be made up for with 10 minutes of idling - you are going in reverse. The fable is that simply running the car charges the battery - true, if you are performing up to half an hour of highway driving.

You are most certainly putting strain on your electrical system, esp. the diodes in the alternator. Yes, get a Battery Tender and hook it to the battery to keep it in top nick. But first, pull the battery, go to a Local, and have them bench-test it for ability under stress. Age of battery means nothing - it is all about how it has been maintained since its first charge.

Killing the alternator is a self-fulfilling thing. You don't want that kind of expense.

[remigio]

thanks.

[daniel911T]

I fought with a similar problem with my '69.

Annoying thing about alternators: they need power to make power. If your battery is low they the alternator won't make enough power to properly charge it back up.

As a first step to solving your trouble, I would strongly recommend taking your battery out of the car and giving it a charge and load test. With the battery fully charged you may very well find that your problem goes away and that the alternator will be able to recharge the battery as quickly and efficiently as it's designed to.

I had other issues, but the thing that fixed it once and for all was battery replacement. (after changing some wiring, the alternator and voltage regulator!)

Good luck!

-Dan

[Tremelune]

For $20, you might as well buy a few:

Battery Tender 021-0123 Battery Tender Junior 12V Battery Charger : Amazon.com : Automotive

They are foolproof.

[timmy2]

That is a very good price, might pick up another one.
Have 2 already.

[remigio]

had the battery charged up and load tested today. it passed. will buy the tender tomorrow.

i have a couple of questions on hooking up the tender. i imagine the battery needs to be isolated from the car beforehand and the tender wires clipped to the battery posts. is this correct?

secondly, my house has a gas water heater and it is in the garage. should i be concerned about ventilation (in a enclosed garage) or battery gassing? can the tender be left hooked up to the battery overnight (or longer)?

thanx in advance. sorry about these newbie questions but i know squat about cars and the learning curve is steep.

remigio

[timmy2]

Battery stays connected to the car, just connect the tender clips to the terminals.
My gas furnace is in the garage, no problems, or I wouldn't be writing this!
Opening the garage door once a day will provide more than enough air replacement for any hydrogen gas produced from a very active charge. Yours is a small maintenance charge and gasses very little with a maintainer.
You can leave them on for months at a time as they are self regulating.

[James Brown]

try this, with the car off, remove the negative battery cable, use a test light touch the negative terminal and touch the other end of the cable and see of the light lights. If it does, there is something that is drawing current in in the car, now comes the hard part, finding it. glove box light, hood light (make sure that that light is NOT on when doing this test) interior light, etc.

[timmy2]

Clock is always drawing a little. voltage can get pretty low after 2-3 weeks....

[Traveller]

Originally Posted by remigio

had the battery charged up and load tested today. it passed.

It passed a load test, but does your battery have any capacity.

You either have an excessive electrical drain, or a battery that self drains too quickly or a battery with very little capacity.

If you need a battery maintainer hooked up to the car for parked periods of less than 2 weeks, you have an issue. I can leave mine parked for a month and it'll start.

[beepbeep]

Switch off every load in the car and connect Ampere-meter in series with battery. If there is more than 10mA current running, something is wrong and draining the battery.

[Traveller]

Originally Posted by beepbeep

If there is more than 10mA current running, something is wrong and draining the battery.

It could be higher than that and perfectly normal.

For example, on a 993 it is just under 50 mA and 22 mA with the immobilizer/alarm disabled.

[beepbeep]

Originally Posted by Traveller

It could be higher than that and perfectly normal.

For example, on a 993 it is just under 50 mA and 22 mA with the immobilizer/alarm disabled.

On ordinary healthy but few years old battery would have something like 50Ah capacity. Draining it constantly with 50mA would drain it completely within 1000 hours...which is 41 days. In reality, it would probably have problems cranking even after a half of that.

So 50mA is somewhat high for a car that is not frequently used.

[Traveller]

Originally Posted by beepbeep

So 50mA is somewhat high for a car that is not frequently used.

But it is what it is. Mine generally sits one to two weeks during the driving season. The on-board voltmeter gives me an indication when battery voltage is too low for my liking.

The only reason why I do keep the battery fully charged during the winter storage months is sulphation prevention. Its why I get the crazy number of years out of my batteries.

[Joe Bob]

Voltmeters draw juice as well. Most meters are on the ignition side as a result.

A tender is a good idea for our old cars if planned non op for more than a couple of days. Just my experience....

[Traveller]

Originally Posted by Joe Bob

Voltmeters draw juice as well. Most meters are on the ignition side as a result.

They do, but the one I have which is "always on", draws less than 2 mA.

For that reason, my voltmeter can be and is wired directly to the battery for a "true battery voltage" reading which is really what I want to know...not some voltage point in a circuit as most voltmeters are wired.

[DRACO A5OG]

check both connectors.

I had non charging issues, found positive connecter was cracked half way down theconnector and if I moved it a bit I would get 12.8 volts to start her then I driver her around and my on board volt meter shows 11.5 BAD. No start.


Replaced connector from a flaps and soldered for extra measures and $5.00 later, 14.2v at meter at speed. No more inconsistant start issues.

Get the Ctek 3300 battery tender/maintainer, $60 cheap insurance.

[remigio]

i bought a deltran battery tender jr rated at 12v and 750mA. will this do? hooked it up this morning (six hours ago) and the indicator is still red. is this normal on trickle chargers/tenders or should i have gone to a higher rated tender?

by the way, thanks for all the comments and advice. much appreciated.

remigio

[Joe Bob]

Look up the word "trickle"......nothing fast about a trickle charger. They will do a day or more before they go "red"....

You want fast, get a battery charger from sears,try to find the analog ones. The digital ones suck.