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Discussion Starter #1
Delco battery on my '04 3.6 is finally kaput. Kept having to recharge and noticed that when driving, the volt meter says its pulling 14.7 volts. This should fall over time, but it stays constant. Find now that the battery doesn't hold the charge for more than 2 days. Anyway, I saw on this forum and from reading Consumer Reports that Optima batteries are an excellent repacement choice. Can anyone who has one tell me what size they installed and does the plastic cap on the top posts clear when closing the hood? I don't think Optima makes a 101 series yet and I would prefer not to have to go AC Delco again.

Thanks in advance!
 

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I use the red Optima batt. It works fine. I did take the red cap off of the possitive post and saw about 1/4 inch if the post off and put the red cap back on. Clears the hood now.
 
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Guys!! how did you fit it under the hood?

I have a Red Top Optima battery just sitting in my garage!!

What do I modify to make it fit?

I thought about using my Angle Grinder to cut down the posts but I dont want to worry about the battery exploding with all the vibration.

????
 

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2006 STS V8 AWD, '95 Ford Ranger
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Be careful trimming the posts. The connection between the battery internals and the side posts is made through the top posts. Trim the top posts too far and you've disconnected the battery. Optima batteries are AGM(Absorptive Glass Mat) batteries and are extremely tolerant of shock and vibration. What will kill them in short order is too high a floating(finish) charging voltage. There will be a notice posted right on the battery with details.
 

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2006 STS V8 AWD, '95 Ford Ranger
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Optima AGM batteries are constructed of sheets of plate material, sandwiched with glass mat. The sandwiched material is tightly rolled under very high pressure. There is more mat than is required to completely absorb the acid electrolyte. This type battery was invented for use in military aircraft. When shot through and through by a high powered rifle not only will the battery not leak, IT WILL STILL WORK. These batteries are sealed but do have a safety valve. What kills these batteries and will cause them to gas out the safety valve is to finish charge them with too high a float voltage. Every AGM battery I have ever seen has a warning notice posted right on it outlining how the battery is to be properly charged. The normal automobile charging system is normally set to the high end of the safe limit. If the setting drifts, the battery is a dead duck in short order. This high limit changes with ambient temperature but properly working auto charging systems are temperature compensated to match. There is no rocket science here.
 

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one of the features of the optima battery is that you can have it sit at any angle. Not sure why you would have to saw, just rotate it
 

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Discussion Starter #12
All,

Great replies, but does anyone know what Optima size group fits a 3.6 CTS? I don't want to mess with the top posts in order to be able to close the hood.
 
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