Red Top Voltage ?
Thread Starter
Drifting
Joined: Jan 2001
Posts: 1,347
Likes: 4
From: Slidell La
Red Top Voltage ?
I have my 1st optima red top. It is about 18 months old. However when I get in the car and leave the DIC on Volts I only see 11.1 volts. It does start and the voltage drops to about 10 while cranking. Fortunately it starts easy. With the engine running I hit 14.2 volts and after driving it will drop to 13.8. These voltages are normal. I bought the car new and these readings are what I had driving it home day 1. SO my question for those of you with the Red Top would you check your voltage before starting when you first get in so I can compare my readings. Thanks Jim
Race Director
Joined: Sep 2004
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From: Redsox, Pats, Celts & Bruins !!! Redsox Nation !!!
St. Jude Donor '06-'07-'08-'09-'10-'11-'12
How long are you letting the car sit between drives? You can get a battery tender and it will keep it charged.
Drifting
Joined: May 2000
Posts: 1,917
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From: Southern NH
The DIC voltmeter is really designed to measure the generator voltage when the car is running, and will always show a lower battery voltage when the car isn't running. Having said that, 11.1V on the DIC with the engine off is a bit low, but not that bad.
The best way to check a battery is measure the voltage across the battery terminals with a digital voltmeter. In general:
12.66V = 100% charge
12.44V = 75% charge
12.22V = 50% charge
12.00V = 25% charge
11.80V = 0% charge
If you measure the battery after it's sat for 24 hours and it's significantly below 100% charge, then it's likely starting to go. My 5 year old Delco AGM had a hard time getting above 12.3V.
If your car sits for more than 3 weeks without starting, it will slowly drop below 12V.
The best way to check a battery is measure the voltage across the battery terminals with a digital voltmeter. In general:
12.66V = 100% charge
12.44V = 75% charge
12.22V = 50% charge
12.00V = 25% charge
11.80V = 0% charge
If you measure the battery after it's sat for 24 hours and it's significantly below 100% charge, then it's likely starting to go. My 5 year old Delco AGM had a hard time getting above 12.3V.
If your car sits for more than 3 weeks without starting, it will slowly drop below 12V.
Thread Starter
Drifting
Joined: Jan 2001
Posts: 1,347
Likes: 4
From: Slidell La
I drive the C5 every 10 days or so. Even after driving and shut the engine off, the voltage still stays low. If it were a wet cell battery I would say it had a dead cell and would not start, but this gell cell is my first. Even at 11.1 volts it still start and the voltage while cranking doesn't go below 10 v, I just don't want to get stuck out and there have been many questioning the quality of OPT Red. vettdvr
