Hey everyone. I have a 2004 s2k. I normally never have issues with the car. For today was the first time I am having issues start the car. While I was away. My car has been sitting in the garage for the last 6 weeks I’m in ny is it a bit cold here. Today I went to start the car and drive it around it didn’t want to start. The battery died. I have a battery boost jumper which I would normally use if my battery died. I got it started but then it kept turning on and off by it self. I have never seen anything like this. Please see the video and you will understand.
Does anyone have any advice for what I can do. Do I need a new battery or is it more serious then that.
thank you

link to video
https://drive.google.com/file/d/1f9V...w?usp=drivesdk

 

Think you need a new battery.

 

Mines on charge again now and taking 4 amps
very small batteries on the S,
6 weeks seems about right given its winter and alarm draws a current.

 

How old is the battery, it's always the first suspect? 6 weeks is usually enough to drain the battery to the damage point from parasitic draws from the vehicle (radio memory, remote locks, etc.). But have it load tested before replacing it. Any auto parts has the tester and most have the battery, it's nothing unusual.

-- Chuck

 

I have had so many cars in so many climate zones I have developed a knee jerk reaction when I realize a battery is goofy or 5 years old: I just replace it. On cars or batteries that sit for a while I use battery tenders (not chargers) for long term maintenance.

 

The video shows engine stutters in a rhythmic pattern. Coinciding with this the dash is seen to flicker.

This tells me the engine is stuttering due to lost spark due to lost electrical power, also reflected in dash flicker.

Normally, once started, an engine can run entirely off the power supplied by alternator. The battery can be completely disconnected, and engine will still run.

However if there were an intermittent short in the battery (the intermittent part would be rare and weird), that would pull all the alternator power away from the car, and short it to ground. It would produce symptoms we see in video.

Or the symptoms could equally be caused by an intermittent short in some part of the cars electrical system. Or maybe the alternator has an intermittent issue and momentarily stops producing power (and at tbe same time battery is too weak to cover for it even for that brief period of stuttering).

My suggestion to start ruling things out:

Suggestion 1 below has been revised based on feedback found in subsequent posts in this thread.

1. Try a different battery. Maybe something from another car in your fleet or a friends car. Anything that can be connected to cars battery cables. Do not disconnect battery while engine running at any time during this process.

If issue goes away using a different battery, its a bad battery. This is your hoped for outcome, as its an easy fix.


2. If that wasn't it, then alternator is next likely suspect. For this test we'll need a fully charged and working battery. Put battery on battery tender type charger, and wait until its fully charged, and can start car unassisted.

With engine NOT RUNNING, disconnect main terminal on the back of alternator. If you're not a fan of sparks and potentially exploding acid battery, disconnect a battery terminal first. The main alternator terminal has a rubber hood, and is screwed in place. Remove the nut, and pull wire away from alternator.

Reconnect battery terminal, and start the car. In this test, you are running the car completely off battery, with no alternator to recharge things. The alternator is out of the picture.

If issue goes away, your alternator was at fault.

3. If issue persists with both tests above, I'm afraid you have an intermittent short in the wiring. A nightmare scenario not wished on anyone. Very difficult to troubleshoot. Get back to us if its this, so we can figure out next steps to try.

 

I'm not sure disconnecting a battery from a running car is a good idea. This may cause a voltage spike that the regulator & fuses can't handle fast enough to save some solid-state parts (like the ECU)? Just a thought...

 

Ok, I stand corrected. Did some online research and thisnis indeed a concern. Often you can get away woth it, but its Russian roulette, as never know if its gonna take out sensitive electronics.

I assumed there would be varistors or other clamping devices in place that would prevent spikes from getting past regulator.

This used to be a common troubleshooting technique back in the pre-semiconductor day, and I've done it on my S and other cars in the modern era. Apparently I've just been lucky.

Still seems ridiculous to me that something that could occur in its own in the wild could cause serious damage, and not warrant a simple charging system design to protect from it.

I will amend my previous post so someone doesn't try to follow it and not read the rest of thread to know there is potential for damage.

 

In my experience a battery cell can drop dead unexpectedly and in a second. There are six of them in series in the battery case. The alternator will try to charge it but can't. Often the battery will test good just measuring the voltage but the battery can't put out enough current (amps).

Battery is a consumable like the tires and wears out.

Until the tests suggested in the thread are run we're all guessing.

-- Chuck

 

Yeah, but cell drop dead then revive itself in regular pattern of around 5 sec alive, 1 sec dead, over and over?