I had the Sport out yesterday, it started in the garage a little on the sluggish side. Then we went to the mountains, it sat outside for 4 hours and seemed to have a miss idle on the next start. I am thinking time for a new battery, cause it ran fine under acceleration, and at idle after it warmed up. So I went to the Optima website and ordered a 34 Red Top.

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2006 LTD Bright Silver loaded with all the needed mods, CCV intact.
Proudly supporting CRD vendors, and their development of quality parts and accessories.
Equipped with HDS thermostat, plenty of heat, faster warm-ups, increased fuel mileage.

flman,

The idle miss you refer to is related to the tune you are running. During the warm-up the injection parameters are the same as stock and as the coolant gauge start to increase (about 1 tick off of cold), we start ramping in the the warm injection parameters. There is a point where the pilot injection can cause a rolling idle for about 1 minute until the coolant gets a little warmer, then it all smooths out as the more efficenct injection parameters take over. It does not sound like the battery in this case.

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[quote="I kinda doubt the CCA's are only 40% of max power a 0 degrees[/quote]

Voltage in a storage battery is a chemical reaction that naturally slows as the temperature goes down. They are rated at a temperature of about 77f.
Here's a clip from just one of many links google came up with. They don't specify 0 but do mention -27 (50% loss)and 32 (20% loss)degrees F.
Further down they indicate the mass of storage batteries make them react to temperature changes slower. So a battery's temperature might not/won't the same as the overnight low
http://www.windsun.com/Batteries/Batter ... emperature Effects on Batteries

"Temperature Effects on Batteries
Battery capacity (how many amp-hours it can hold) is reduced as temperature goes down, and increased as temperature goes up. This is why your car battery dies on a cold winter morning, even though it worked fine the previous afternoon. If your batteries spend part of the year shivering in the cold, the reduced capacity has to be taken into account when sizing the system batteries. The standard rating for batteries is at room temperature - 25 degrees C (about 77 F). At approximately -22 degrees F (-27 C), battery AH capacity drops to 50%. At freezing, capacity is reduced by 20%. Capacity is increased at higher temperatures - at 122 degrees F, battery capacity would be about 12% higher."

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Atlantic Blue 06 CRD Limited (his)
Joined by a 2000 XJ Classic (hers)

Well, it is cranking over slow in comparison to the LTD, and the Sport has 2X the mileage, so it is getting a new battery. Any ways, thanks for letting me know that surging idle is related to the tune.

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2006 LTD Bright Silver loaded with all the needed mods, CCV intact.
Proudly supporting CRD vendors, and their development of quality parts and accessories.
Equipped with HDS thermostat, plenty of heat, faster warm-ups, increased fuel mileage.

Actually, now that I think about it, neither of the Jeeps have exhibited this surge idle at any time during a cold start in all the years I owned them. So it is new on me, and the vehicle was only sitting at about 30 degrees ambient for 4 hours after a 30 mile trip?

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2006 LTD Bright Silver loaded with all the needed mods, CCV intact.
Proudly supporting CRD vendors, and their development of quality parts and accessories.
Equipped with HDS thermostat, plenty of heat, faster warm-ups, increased fuel mileage.

False

I have proof that heat rises. Here's a pic taken this morning (2 degrees outside when I took the pic) that shows snow melted on my hood.

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2015 Ram Ecodiesel/Big Horn/4x4/Quad Cab
2016 Arctic Fox 22G/Onboard 2500 LP Cummins Onan Generator/160 Watt Solar Panel

I took the road less traveled. Now I'm LOST.