I have a 45k old 2k2 maxima. After the movies i could not start my car. Had to ask the guys to give me some juice. Is my battery dead, will I have to replace it. If yes? What? Where? How much? What is he cheapes way to deal with this? had never replaced a batter on any of my cars.

 

couple of things, have you gotten the battery tested, you can get it tested free of charge at autozone. have you checked the water level. If the battery is good, then they can test your alternator to see if it's going bad. If nothing turn up, is there something that you might have left it on, i.e headlight or courtesy light on?

 

probly dead, maybe $60? Nissan dealer or an Advance Auto or AutoZone type place

 

The car turns on normaly. Passport reads 12V when the car is off and about 13.5V when the car is on. Passport (radar detector) has an option to measure current. Should I keep driving with it or should I just get a new one?

 

try this:
Leave the engine off but the radar detector plugged in to measure voltage.

Look at the voltage with the engine off. If should be ~ 11.5 - 12.5 Volts.

Then, put on your headlights. The voltage should only drop 1 or 2 volts. If it drops a lot, then the battery is fried. If, when you put the headlights on, the car electrical just goes away (you'll hear relays clicking) and the detector shuts off, that's because of too great of a voltage drop. If that happens, then the battery dropped a cell or 2 and is fired.

Shorted cells happen a lot these days. Back in the old days a battery gave you some warning when it was going out, you would hear the engine crank slower before it finally gave way. That's because when they went, it's was because of chemical breakdown. These days it seems, more often than not, batteries just drop a cell or two and die and instant death. Two of my brother-in-laws own car shops, that's what they're seeing. Some still die the normal way, I'm just saying cell failure seems to be a lot more common with today's batteries.

 

I agree with having the battery load tested. The car has a battery saver that turns off headlights and courtesy lights after about 5 minutes so that probably would not be a concern.

 

Works, so I am not gonna bother to get a new battery. Now the question is where did all the energy go yesterday. Is it possible that headlights did not go off...? I know they should , but may be something melfunctioned.
I don't know.

 

Still wouldn't hurt to have a free battery load test.

 

Have it load tested, only way to test without doubt. My poor-man's load tester really doesn't load the battery as much as it should be. It does work when a cell is dead.

The other thing to consider is that you drained the battery then recharged it in the car. A car battery isn't designed to be deep-cycled like that.

When a car battery is completely drained, the worst thing you can do is jump it then drive the car because the alt won't exactly "trickle" charge it like it should be when it's been drained. No one ever does that because your stuck, you have no choice.

On a battery like a car battery that's not meant to be deep cycled, the alt will push enough amps into it to get it hot and that will cause some chemical changes that will shorten its life. It may still hold up for a while but that deep cycle will definitely take some months off its life.

 

Not to mention the strain put on the alternator when it's charging a nearly dead battery. It produces a lot of heat within the alternator housing while charging it. That can also shorten the life of the alternator

 

There are a couple of battery tests. You can purchase one of the acid testers which are easy to use and check each cell.

The other test is a load test which requires a machine to test. The load test will require a fully charged battery. The battery tester will charge your battery for you but you will have to wait till they are done (can take several hours for a seriously depleted battery).

If the battery checks out then the next step is to have the charging circuit tested. You can also ask some part shops to test the charging circuit on the car. They use a handheld tester which hooks up to the battery. Pretty easy to do, only takes a few minutes, and is usually free as they want to sell you a new alternator. I know Kragen's offers this but I don't know where you are.

 

If you need a good conventional battery - go to Costco - they got the best batteries accroding to consumer reports. and they are cheap with 5 year replacement warranty. They are made by Allied signal or something like that....
they sell Optima's as well if you are into that type of thing..

 

Here are a couple of q+d tests for the charging system.

Start the car with the door open and keep an eye on the interior lights. They should get dimmer while you are cranking the engine, then, after the engine starts, they should be noticeably brighter than before you started the car. If this happens, then almost certainly the charging system is OK. If they are not brighter after starting than before starting, then you probably want to get your charging system checked out. It may be easier to be certain of the light levels before and after starting if you do this at night, or in a dim garage. Note that you have to be looking at the light level of incandescent light bulbs: the brightness change of LEDs with voltage is less, and if you have HID headlights, their brightness does not vary at all over a large range of battery voltage.

Another crude but no-cost test is this: with the engine running at its hot idle speed, listen carefully for the alternator whine while you turn on the headlights (high beams), rear window defroster, and step on the brakes. If everything is operating OK, you should hear an increase in the whining tone of the alternator. It's subtle and you have to listen for it, but it is there. (Helps if you put the windows down and do this in a garage or next to a concrete wall, so that the sound from under the hood will be reflected back to you.) Turning on all these devices causes about 35 amps of load which is enough to tax the alternator at idle speed. Obviously, since you are listening for a fairly quiet change in sound, do this with the radio and the AC/heater all turned off.

With the IC-based voltage regulators that are used in all modern cars, odds are that either the alternator and charging system work correctly or they do not work at all. If you have a lot of corrosion under the hood then you might get some bad connections that would cause the system to have limited capacity and/or low voltage.

 

I agree about having it load tested. I had it tested by a handheld tester and later a larger machine where I had to take the battery out and into the store (Schuck's auto supply). It very promptly failed on my 2K2 Max w/16.5K miles at the time.

I brought it to a dealer knowing that I'd have to pay 75% of the cost of the batt (cuz of the terms of batt warranty) if it was bad. They told me the batt is bad and they found nothing wrong w/the electrical system. I figured the latter was worth the peace of mind even though I wasn't saving any $ on a battery compared to Costco since the basic warranty on the car will run out for me end of November.