Constant Battery Problems

[ludalex]

My mother who is a senior drives a 1993 Camry (with just 65,000 miles on it), and it regularly has to be given a boost. At first, we thought it was the battery itself, so we changed it. But even now, with a new battery (about 6 months old), every couple of weeks, the car won't start. The AAA people who come to boost it say it's because my mom doesn't drive enough. She goes out at least once a week, and she starts the car a few times a week. it's true that she never takes in on the highway.

The car is with my mechanic now, and he can't figure out what the problem is. In fact, I told him that my mom is willing to pay whatever is necessary to fix it (it has no other problems), but he simply doesn't know. Clearly, something is draining the battery when it's sitting in the garage but it's nothing obvious.

Would anyone have any thoughts?

Thanks!

[Stillrunning]

Ask mechanic to check for what's called "parasitic loss".

[ludalex]

Thanks! I have told him, and he is aware of this issue, but can't find the source of the drain. If he can't definitively fix the problem, are there any makeshift solutions? For example, would it help if I took the car out for a 30-minute spin on the highway once a week?

Thanks again.

[Stillrunning]

Buy a solar or plug-in battery charger/maintainer to leave on between driving.

[ludalex]

Thanks again, and I really appreciate the advice, but it's something that would apply to me, but not to my mother. Unfortunately, she's 75-year old, and I can't even imagine bringing up with her the idea that she would be opening the hood, connecting the wires, etc. And I don't live close enough to help her with this every time. Nor are there neighbors that she can rely on.

Since the loss of power doesn't happen immediately and if the mechanic can't find the source of it (esp. if it's the wiring), would it help to buy a specific (expensive/longer-lasting?) kind of battery?

[JohnGD]

Get a digital multimeter if you don't already have one. Harbor Freight has one often on sale for about $3. These can test 10-100 mA DC.
http://www.harborfreight.com/7-funct...ter-90899.html

How are the battery post connections? Any corrosion crust build up?

1. With the engine off for more than 12 hours. Measure the battery voltage. What's the reading? (Doors closed so the courtesy lights don't put additional drain on it).

2. With the key, all lights and accessories OFF. Disconnect the battery ground cable and probe the multimeter in series with the negative cable and battery post (positive probe to the cable, negative probe to the post). What reading do you get?

3. Measure the battery voltage again just to see with the post disconnected if you get the same measure as in #1.

4. Connect everything back. Start the engine. What's the voltage at the posts? Between 13.5-14.5v?

5. Consider the free battery and charging system test at Autozone or your local parts store.

Dirty battery posts can cause problems too. So use a $1 terminal cleaner to clean them and the clamps:
http://www.harborfreight.com/battery...ner-94450.html

[dc_98_cam]

Check for DC ampere leakage .... a multimeter set to DC amps in series with one of the battery terminals... A few milliamperes (0.001) leakage is probably normal, but not much more.

If there is any significant leakage .... maybe greater than 0.1 amperes,
then check the alternator for defective diodes. It could be that the diodes that are internal to the alternator are defective ... after 18 years or so ...
and allowing current to conduct away from the storage battery.

It used to be standard procedure to replace alternator diodes every few years. ... At any rate, this would be something to check.

It used to be that you would remove the alternator and take it to a shop ... maybe Autozone ... and have them test it for you.

I don't know if an installed alternator could be tested ....

Like the previous poster mentioned ... all terminals and battery posts need to be bright and shiny before they are clamped together, in order to avoid
any potential electrical problems.

[RichieRichJP]

Have you actually confirmed that there's a parasitic loss of power directly related to the battery?
To me it sounds like you have other issues especially given the fact that you've already installed a new battery.

What happens when you turn the key in the ignition? What do the lights do? Do you hear anything from the engine bay?

Here's what I would check:
- battery terminals. Old terminals may not conduct well for various reasons including fitment and conductivity. If they're old, I would replace them with something new and more solid.
- the starter solenoids could be wearing out causing intermittent start-ups and failures. If your car doesn't crank, try giving it a whack and see if you can crank the car up. If it doesn't work, its probably not the culprit.
- alarm system. Does your car have an aftermarket alarm by any chance? The anti-theft could be randomly kicking on/off causing the car to (or not) randomly be able to crank. This could be because of loose wiring.
- alternator. Bring it to Autozone and have them test it.

[Pauloil]

you also need to do a voltage drop test under load on the cables between the alt. and the batt.: like asking the cable how many volts cannot go through with the motor at 2K rpm with headlights on , rear defrost and blower on high. see link for explaination. all alternator evals. should start with a check of the cables. if the pos. cable by the batt. is hot after a drive, it is bad.


http://www.aa1car.com/library/voltage_drop_testing.htm

[Stillrunning]

Originally Posted by ludalex

Unfortunately, she's 75-year old, and I can't even imagine bringing up with her the idea that she would be opening the hood, connecting the wires, etc.

Plugs into cigarette lighter.

[hill8570]

Define "regularly". I would hope that the mechanic has made sure that the alternator is properly charging the battery, but I'd want that ruled out before looking at things like parasitic loss.

[ludalex]

Thank you, everyone, for all your advice and suggestions! This is my first time on this forum and I am really impressed. My mechanic is now convinced that this is a wiring issue (he checked the battery and the alternator), but he hasn't yet been able to find the source of the leak. Just to reassure everyone, he won't be charging me for this anything extra, so it's not something he is doing just get in some additional hours of labor. He is keeping the car in his garage and wants to wait until the battery is drained. He thinks that will help him figure out where the problem is.