2002 Camry - First failure: Battery (maybe more?)

[Conan555]

My camry died yesterday, and I discovered that it was the battery. After 3 jump-starts to get to/from work, I picked up a new battery and installed it today.

I did alot of research about the charging system, just in case it was something other than the battery at fault. (The car died on me once after a jump start at a traffic light, and again when I pulled into my parking spot, which let me to suspect something w/ the alternator) From what I've read, the output from the alternator should be ~14.5 volts when the car is started.

After I installed the battery, the car started up just fine. I measured the voltage at the battery, and it read 14.1, as expected.

Then, I went inside the car, turned on the fan, high beam, defogger, and every other accessory i could find in the car.

I went back out to measure the voltage accross the battery, and it was back down to 12.5ish volts.

After shutting down the engine and restarting, the voltage stayed at 12.5ish volts. It didn't seem like I could get the voltage back to 14.x volts?

I waited a couple hours, went back outside, started the car, and measured the voltage again: 13.x volts. I decided I was going to try driving it around the block, but chicked out when I backed up, and the car started to feel like it was going to stall. I got out and measured the battery voltage again while the car was still on: 12.x volts.

The car also studdered like it was about to die. I called the toyota dealership, and he said, "I wouldn't worry about it." He told me to drive a couple miles and it should steady out (which it did. I guess the ECU was relearning)

So my question is, is this normal??? Shouldn't the output at the battery be 14.1 volts (to charge the battery)??? How is my battery charging if the voltage is 12.x volts?

[Forced Induxion]

if your battery dies again you may want to check out your alternator.

[majorgercko1]

I think the vatery charges when you have the car running. Its no problem trust me mine is a 12 v battery works fine.

[toyomoho]

Connect the voltmeter to the battery terminals. Battery voltage with engine and all accessories off should be 12.2-12.9V. Start the car and check voltage between idle and 2000 rpm, accessories off. This should be between 13.9-15V when you first start a cold engine.

A fully charged battery is 12.65V, 50% 12.25V, 0% 11.89V

[marc780]

I understand what you are trying to ascertain, alternators are not cheap. My guess is yours is marginal, but it will give some more service who knows for how long, and you dont wanna be stranded but moneys an issue.

Firstly, could your alt belt be glazed, loose or slipping? This is important to your decision. Make sure the belt is perfect in tension and condition before proceeding.

After shutting down the engine and restarting, the voltage stayed at 12.5ish volts. It didn't seem like I could get the voltage back to 14.x volts?

Here's the probable reason, try this test again but let the engine idle for 3 minutes after starting and THEN take the reading. Your reading was low because the alt was busy trying to replace the juice you used to start the engine. If it now reads 13.9V (Barest minimum) or more, this alt might have some life left in it.

12.5 volts at idle, even with a load, sounds too low. So like i said i believe the alt is marginal. And nows summertime and the heat isnt going to help this problem one bit. If it were my call id just change out the alternator.