Spontaneous Battery Discharge

[Mutad0r]

Yesterday, I thought I'd take me friend out for pizza. The car started fine, no indications of trouble, no lights that shouldn't be lit. I drove to my friends place, picked him up, and on the way to the pizza place we passed by the place where he worked (construction site [He wanted to give me somthing]). I pulled in, and turned off the engine. He couldn't find the stuff, so we were about to go, yet when I tried turning on the car, all I got was a clicking sound made by the motor that starts the engine. Also, my phone that I had connected to the charger suddenly went "BleepBloopBloopBleeBlooBleepBloopBleeepBlepbLeBPL bep". The battery was drained, no lights would turn on. We ( mostly me ) pushed the car uphill back to the road and push-started it. The car didn't run very well, and I could only give it a small amount of gas (otherwise it would start stalling/breaking if I tried to give it some more). By the time I got it back to my fathers place, a couple of lights inside the car had started to work already ( so the battery was charging ). I left the car there, my father left the battery charging overnight, and I came here to seek guidance on my quest against the dark forces at play. What could cause such a thing? There was no warning whatsoever.

[shorod]

When you tried to start the engine did you just get a single click or a series of clicks? Did you inspect the battery cables to make sure they were clean and tight?

Do you have a multimeter or voltmeter that you can use to check the battery voltage?

-Rod

[Mutad0r]

I can't exactly remember if it made multiple clicks the first time, but every time after that it made only one. Also, when I got to my fathers place, I tried starting the engine ( the battery had accumulated some charge, remember?) it only had enough power to turn the engine a couple of times, certainly not enough to start it. The battery is now charged and the car works, but I suspect it could happen again. All the connections should be clean. And I have a Voltmeter. After charging it read about 13,8 , with the engine started, it went to 14,2.

[shorod]

The voltages look good now, and the 14.2V would suggest the alternator is working. You could try switching to VAC and see if you are getting more than a few mV (0.001V) of AC - tests the diodes. You should also check the minimum voltage when the starter motor is cranking the engine over. If you're dropping below 10.5 you either have a huge load on the starter (thick oil or bad starter) or the battery capacity is low.

-Rod

[Mutad0r]

Thank you for your reply, however, I don't understand what exactly I'm supposed to do (Non-native English speaker). Googleing VAC doesnt help either.

You should also check the minimum voltage when the starter motor is cranking the engine over. If you're dropping below 10.5 you either have a huge load on the starter (thick oil or bad starter) or the battery capacity is low.

Do you mean that I should have someone see how low the voltage goes at the time of starting the engine?

[shorod]

Sorry, VAC is AC Voltage, or "Alternating Current" Voltage. The voltage you were reading was Direct Current Voltage or VDC. The "alternator" is actually and AC generator with diodes/rectifiers to produce DC voltage. If one or more of the diodes is not working properly, you will see that on the multimeter as a VAC reading

As for checking the voltage under load, yes, with the multimeter set to VDC and connected to the battery, have someone turn the key to the Start position and see how low the reading on the multimeter drops to.

-Rod

[Mutad0r]

Update: Today, as I tried, the voltage with the car off was 12.7V, with the engine running it was 13V and while starting the engine it dropped to 10.61V

As I understand, the alternator is in the generator. What remains unclear is where should I connect the multimeter to? My best guess is to connect it to the battery, set to VAC and have the engine running. Because it's a little hard to reach the generator when the engine is running.

[shorod]

You're correct. The alternator (sometimes also referred to as the generator) is connected to the battery. The battery will help filter most of the AC. As you suspect, connect the multimeter to the battery with the engine running and check for VAC.

Depending on how long the battery has been sitting, 12.7 V is pretty good surface charge. Likewise, only dropping to 10.61 V when the starter is engaged is decent. With the engine running, 13.0 V is a bit low though. I would expect that to be more like 13.6-14.4V.

The next experiment you may want to do could consist of using a clamp-on DC current probe, series test light, or series current meter with the positive battery cable to see what kind of current draw is on the battery with the rest of the systems off. Depending on the car, the series test light may not work well due to some of the electrical devices that may be trying to activate.

-Rod

[Mutad0r]

I just checked for VAC and it showed 2mV with the engine on and 1.5mV with it off. ( I had the multimeter set to 200m under VAC, so I guess a reading of 2.0 = 2mV). Am I in the need for a new alternator?

[shorod]

You don't have significant AC voltage, so the diodes appear to be working fine. I'm still a bit concerned with the output of the alternator though. It doesn't seem to be supplying much charge voltage. I'd suggest you stop by a local parts store and have them check the charging system with their system mainly to confirm the readings you're getting with your meter.

-Rod

[Mutad0r]

I haven't had the time to try the things you suggested, but my cars illness got another symptom. About an hour ago I was trying to start it but it wouldn't it only made the clicking sound again, but the battery light was on ( last time, nothing even worked). I tried starting it multiple times and at about the fifth time it started. All lights worked and the battery had power. I turned the car off and it clicked again, this time it took 4 tries to start. I drove a bit and the problem disappeared. Is my car haunted? Does the ghost wish me not to make it to the job interview tomorrow?

[shorod]

It's probably in your best interest to take the car to a chain auto parts store that will check the battery and charging system with the battery in the car and have them analyze the battery and alternator. The first time you listed voltages with the engine running the voltage was just fine at 14.2 V. The next time you listed the charging system voltage with the engine running you listed it at 13V (low alternator output). With the issues you're having, either you have a loose/dirty connection somewhere or your alternator is not working reliably. The parts salesperson may be able to tell you what the issue likely is from looking at / touching the cables.

-Rod

[Mutad0r]

Since I only paid 200€ (about 275$) for my car, I doubt it's worth taking it to a shop, since ( at least here ) the repairs would cost almost as much as I paid for my car. It's a small town, and they're really money-hungry.

I may not be able to repair the car, but at least I may be able to expand it's lifespan.

Anyway. The car got a new symptom. I can hear the engine through the speakers inside the car. Literally. Turning down the volume doesn't affect the sound of the engine from the speaker. Putting the radio on mute however also mutes the engine from the speakers. Also, the sound of the engine is a little more high-pitched that that of the real engine. And if you ask how I know that the sound is the engine, well, when I accelerate, the sound of the engine from the speakers changes accordingly.

I tell ya, it's haunted..

Also, Once I got home with the car it wouldn't start anymore, the same clicking was all I got. However, the lights would turn on and the radio would play, but if I turned the key to start, all the lights went out.

[shorod]

Engine noise over the audio system suggests either a grounding issue or possibly an alternator issue.

As for taking it to a shop, I was suggesting an auto parts store which in the US will usually test the battery and charging system for free. I'm not sure if you have anything like that in your area.

-Rod

[Mutad0r]

Thank you for your help so far. I'm not sure there are any free services, but I'll sure check. I do have a tiny question, is the alternator a part of the generator, or simply another name for it?