What up with my stock battery?

[03SvtSonicCobra]

Well i am trying to get my Cobra ready for the spring,I know my battery is dead from storage so i buy a battery charger and charge my battery. Here is where the problem begins the charger says my battery is fully charged but the eye in the battery is red???? The car fires right up with out the charger on it but i know this means my battery is bad(red eye). How does a 2 year old battery go dead!!! I was wondering when i take my car in to ford will they replace my battery for free under warranty or will they just make me buy a new battery. If i am not mistaken batteries last 3-4years correct? I heard other stories about 03/04 Cobra batteries dying for no reason, even when they are not in storage sitting there like my Cobra was. :shrug:

 

[HISSMAN]

You can never really tell by that green eye. Best thing to do is take it and have the battery tested. Next time you put it into storage use a trickle charger.

 

[03SvtSonicCobra]

yeah thats what i got now live and learn. I have it charging right now at 2amps(trickle), i am just scared that i am going to walk out to my garage on fire, or my cobra motor on fire with leaving the charger on.

 

[03yellow]

Try to move the battery side to side. Shake it a little. Sometimes the eye will flip over.

You may want to ask it questions before you shake it (8ball)....like will I buy a kenny bell supercharger!

 

[03yllwguy]

I would just take it in, should be no ?'s asked in theory over a $50 battery.

 

[ChicagoMike]

Don't use a trickle, they can overcharge and cause damage. You need THIS:

http://www.batterytender.com/

 

[HISSMAN]

Just get something that turns off when the battery is charged. I have a trickle that quits charging when it is charged, and then starts again when it senses the batter is getting low. It was like $39.00.

 

[eiblish]

:coolman: Not unusual for a Cobra battery to have only a two year life. Mine lasted just over two years, and several on this forum have said the same. Get yourself an Optima battery if you want a longer life, but, of course, it will cost more than the stock battery.

 

[Fast Willy]

put it on a battery tester, thats the only really safe way to figure it out.

 

[x14]

Yup, battery last 2-3 years. It will not be able to keep the charge as long in the 2nd year. I plan to get an Optima red top when mine goes.

 

[ModsAway]

I had a battery tender on mine last year and this year (winter storage) and went out about a week ago to find my battery dead (red eye as well).

Jump started my car, battery receives full charge and remains charged (alternator doing its job well).

Immediately after turning my car off my battery slowly (about 0.1 volts per 2/3 seconds) loses its charge until it is again completely dead.

I will jump it in the spring and take it in for warranty.

 

[VenemousShadow]

I had a battery go bad so I replaced it, a week later my alternator went out, go figure on that one.

 

[03SoCalCobra]

Mine started slow-cranking after about a year, replaced it and the alternator went 1 month later. The second battery is about 75% gone already.

BTW- if you're ever driving and starts feeling like it's misfiring under WOT boost.. and gets worse... then the radar detector dies... followed a few minutes later by the Mach 460, that'd be a good time to find a gas station or other parking area really fast.

 

[03SvtSonicCobra]

I had a battery go bad so I replaced it, a week later my alternator went out, go figure on that one.

This happened to two people on this thread whats up with that!!!!!! I hope it
don't happen to me. Now i am scared to change my battery. Could anyone else chime in with there baterry horror stories, or alternators taking a crap on them after battery change. and warranty coveing there batteries???

 

[NyteByte]

or alternators taking a crap on them after battery change. and warranty coveing there batteries???

My guess is that the two are related. There was probably something already wrong with the alternator which caused the battery not to charge properly.

Finally the problem gets so bad that the battery dies, but the alternator also goes out soon after.

 

[JB]

My guess is that the two are related. There was probably something already wrong with the alternator which caused the battery not to charge properly.

Finally the problem gets so bad that the battery dies, but the alternator also goes out soon after.

usually its the other way around...

alternator burns itself out trying to keep a dying (internally-shorted) battery fully charged

 

[03SvtSonicCobra]

Is it true if you smaller pulley don't your alternator burn up faster???

 

[JB]

smaller upper pulley doesn't turn anything faster besides the blower

larger lower pulley is what spins your alternator and stock idlers past the intended RPM

 

[harry gilbert]

The acid test we used on lead-acid storage batteries is to check the voltage across the battery. Should be 11.8 - 12.5 volts. Now, keeping the voltmeter hooked up, turn on the headlights for a few minutes. The voltage should gradually start to drop, but after 5 minutes or so should still be around 11 - 11.5. When the car is running, the voltage should be 12.5 to 13.5. A good battery will hold it's voltage for at least 5 - 10 minutes under a load (with the headlights on). A battery that sits for a long period of time will become sulfated and lose it's ability to give/accept a charge. If the battery is sulfated, the voltage will drop rapidly. When cranking the car, it might drop down to 8 or 9 volts.

There is a way to salvage a sulfated battery that will usually work. Deep cycle the battery: drain it ALMOST dead by leaving the headlights on (car not running) then charge SLOWLY to avoid heat buildup. Repeat this again. This has saved more than one battery for me over the years if it's not too badly gone.

 

[03Cobra19]

The acid test we used on lead-acid storage batteries is to check the voltage across the battery. Should be 11.8 - 12.5 volts. Now, keeping the voltmeter hooked up, turn on the headlights for a few minutes. The voltage should gradually start to drop, but after 5 minutes or so should still be around 11 - 11.5. When the car is running, the voltage should be 12.5 to 13.5. A good battery will hold it's voltage for at least 5 - 10 minutes under a load (with the headlights on). A battery that sits for a long period of time will become sulfated and lose it's ability to give/accept a charge. If the battery is sulfated, the voltage will drop rapidly. When cranking the car, it might drop down to 8 or 9 volts.

There is a way to salvage a sulfated battery that will usually work. Deep cycle the battery: drain it ALMOST dead by leaving the headlights on (car not running) then charge SLOWLY to avoid heat buildup. Repeat this again. This has saved more than one battery for me over the years if it's not too badly gone.

Great advice! Thanks for the tip. :thumbsup:
all my batteries (past cars, one mustang) have lasted many years. I've never heard this two year rule. I've killed them, and got them jumped a few times. No prob.

Is this a big issue with new cobra alternators/batteries?, if so why?