When running the 7 for an hour to charge it up I turn it off then turn it on to see the voltage and it reads 11.3.
When starting it will crank slowly at first then pick up speed over 5-10 seconds and finally start up.
The Optima blue top is about one year old and even with a long slow charge the voltage drops drastically as soon as I remove the charger.
I think the optima is defective.
What should I do to prove or disprove this theory?
The car is a 1979 SA.
Dennis

 

Just running the engine is not enough to charge it up. Take her for a good drive and try again...

 

it needs to charge on the drive as kentetsu said. Otherwise get a 110 volt charger and charge properly.

 

Are you using an electric fan? Mine required a second gen alternator when i installed my Black Magic electric fan. I also replaced my ground wire battery terminal; using custom 4 gauge welding wire.

 

sounds like you have a bad ground somewhere.

 

I was having the exact same problem with one of my cars less than a month ago...turned out to be a bad battery. Have a shop load test it, shouldn't cost much, even less if you know someone.

good luck

 

Thank you for your replys.
The problem is the same whether I slow charge for 10-12 hours at 2 amps or at medium rate of 12 amps or quick charge at 25 amps.
The charger has an automatic desulphate mode and full charge switch over to a maintenance setting.
The voltage still drops rapidly when the charger is removed.
It acts like a bad cell, but I do not know if that is possible with this type of battery.
The alternator puts out around 14 volts at fast idle.
I will:
1 Remove battery
2 Swap in a standard good one to see how it acts in the car
3 Take the Optima to an auto parts store for load testing.
4 Try to find the dimensions and position to cut out the panel for the storage bins so I can do the battery relocate mod.
5 Try a yellow top next time

 

Installing a two year old conventional battery cleared up all the problems.
The Optima is FUBAR.

 

That's a drag man, but at least the mystery is solved. Thanks for posting back with your conclusion.

 

I've yet to see and electrical thread where someone doesn't respond with the old "must be a bad ground."