Tech Help Please

Adower

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Today I was driving my car and did a hard pull up to near redline. When I got off the accelerator the car died on me. Motor off, CEL on, battery light on. First time this has ever happened.

I coasted a few feet and stopped the car. Started the motor and it fired right up like nothing happened. No CEL, no weird idle, no battery light on, etc.

I have been having some issues with a parasitic draw and my battery. I use an optima red top and if I let the car sit for a while (a few weeks) the battery will drain (parasitic draw?). I put a trickle charger on the battery and on two occasions when I put the battery back in it has off gassed on me after driving it for a short while. I've read a few different things about this such as you cannot trickle charge a optima red top and there is a certain way you have to re-charge them. After the second time the battery off gassed I was wondering if the battery was getting overcharged. I put a volt meter on the battery and it was getting 12V while the car was running. If I drive the car regularly I don't seem to have any issues with the battery.

Anyone have an idea of what could be the issue with the car dying after a hard pull?

Car is a 98 cobra with 26K miles
Stock motor/stock cams/ short runner cobra intake
Vortech S trim intercooler on 10 lbs tuned
Long Tubes
 

DSG2003Mach1

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You need a charger with the correct mode for an Optima - I believe it's an AGM setting.

Sounds like you might want to monitor battery voltage while driving and see what its doing, low voltage and bad grounds can make all kinds of crazy shit happen
 

9397SVTs

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I'd check the alternator. At idle, the battery should be getting 13.5-14V, not 12V.

During normal driving, the electrical system, while not functioning properly, can provide an adequate output. Under load and high demand, it can't keep up.
 

Adower

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I'd check the alternator. At idle, the battery should be getting 13.5-14V, not 12V.

During normal driving, the electrical system, while not functioning properly, can provide an adequate output. Under load and high demand, it can't keep up.

Darn. I thought it was supposed to give 12V at idle. Which is what it is doing now.
 

Adower

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You need a charger with the correct mode for an Optima - I believe it's an AGM setting.

Sounds like you might want to monitor battery voltage while driving and see what its doing, low voltage and bad grounds can make all kinds of crazy shit happen

Figures. My charger definitely doesn't have an AGM setting.
 

Adower

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I'd check the alternator. At idle, the battery should be getting 13.5-14V, not 12V.

During normal driving, the electrical system, while not functioning properly, can provide an adequate output. Under load and high demand, it can't keep up.

Shoot I misspoke here. At idle with car on it’s getting 13.9-14.1v. At car off the battery is getting 12v
 
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