skyspydude

I have been having a problem that is starting to worry me. A while back my vehicle was having some issues with the battery. If one of the interior lights was left on for even a short period of time (i.e 1 hour) the battery would be nearly completely dead and the vehicle would have to be jump started. I went to the dealership and got it checked out and they said the battery was going bad and they put a new one in. At this point everything was working fine. Now I think the problem is even worse. A few days ago I was doing a little work on the vehicle and I had the radio running for maybe 10 min with the car off. When I went to start it, all of the electronics went off and the car barely turned over. I drove it around a while to charge up the battery again. Today I did essentially the same thing to see if the battery was charged and this time the car didn't even start and I had to get it jump started. I drove to the dealership and told them what was going on and they looked it over and said everything was alright and that "It shouldn't be doing that." So I was wondering if anyone might be able to give me some more insight to why my vehicle is doing this.

gazi001

Check the alternator output voltages while the engine is running. If you got right amount of voltage like 12 volts or so ok. Then you have to check if is there anything left on since you turn off the engine. Certified electrician could do this for minimum fee.

thomas1

While the engine is running the voltage should be 13.5 to 14.5 volts...Another if that voltage is good, then maybe you have a defective starter, or the battery cable is bad going to the starter....(corrosion)....

code58

SSD- the FIRST thing YOU shouldn't be doing is going back to that dealer!!! With proper testing equipment, determining why it is doing it IS NOT ROCKET SCIENCE! If you were in So. Cal. instead of Co., I'd be happy to do it for free, but I'm afraid my arms aren't that long.
1st. thing, battery should be charged. Charging with a charger is necessary, preferably a smart charger. An alternator is not designed to charge a battery from low or dead condition. Then it needs to be load tested with a carbon pile load tester. I have both carbon pile and conductance testers but still trust the CP over the conductance, though I use the conductance often.
2nd. is to use an amp clamp tester on the neg. battery cable to see what the draw is with nothing on, and no doors open to cause draw. It should be no more than ROUGHLY 50 miliamps.
3rd., IF all of those things check out good (which I suspicion they won't), you need to disconnect the battery when the car is not being used (preferably overnight or longer) and then have it tested to see if there is ANY loss in voltage or CCA's or reserve min. (if you are able to test those things) I have only ever ONCE in my career seen a battery that load tested fine, load test bad the next day. And that was sitting on the floor! I charged it 3 different times and load tested perfect and the next day load tested bad. Never did figure that one out, but the battery went in the junk battery pile.
I would suggest, since the dealer doesn't seem to be competent, to look for an AUTOMOTIVE ELECTRICAL shop. If you have one in your area, and they are competent, they should have no trouble finding the problem.

There's more to the picture, but I doubt you'll need that info. And yes, you should be showing at least 14 V, I prefer to see about 14.2-14.4 at about 1500 RPM. On a 12V system, anything less than 13.6-13.7V is going to leave you with battery problems in the long run.

skyspydude

Well I don't have the equipment for a load test or anything right now, so I just decided to do a voltage test of when the car was on and off. When I did both I got a reading of about 16.4v. This seemed a bit odd to me, but it might just be something simple (I'm just an idiot). Let me know what this higher voltage might mean so I can make the decision on whether or not to go out and take further action.

code58

SSD- It wasn't exactly clear when the voltage was 16.4V. I would have to assume that was with the car running. Since you said you checked it both on and off (I assume running and not running), what was the voltage with it off? You should definitely NEVER see voltage of 16.4 under any circumstances. The voltage regulator is there to keep the (running) voltage between roughly 13.6V- 14.6V. I would prefer to see it at the higher end, but since voltage regulators haven't generally been adjustable for over half a century, you have to accept what the internal regulator gives you in that general range.
16.4V would generally damage a battery from overcharging, but doesn't explain why the dealer would declare everything Hunky Dory. I still feel you need an automotive electrical shop since the dealer "acted dumb" (guess maybe it wasn't an act)
A voltage test with it off doesn't tell you a lot unless you turn the lights on for 30 seconds or so to drain the surface charge. It still doesn't replace a proper load test.