There are Group 65 AGM batteries available that are 950 CCA. (Enersys Odyssey Extreme).

The higher CCA is due to more plates inside the battery.

Enersys can stuff more plates inside the same size Group 65 case because the individual plates are thinner.

Enersys can make the plates thinner because they claim to use pure lead (rather than recycled lead), and the lack of impurities in pure lead make the plates less likely to break apart, as the amalgams of recycled lead have been known to do if made too thin.

More pure lead stuffed inside the box makes these batteries heavier than equivalently sized flooded wet cell, as well as other AGM batteries which are not made with a Thin Plate Pure Lead manufacturing process.

The fact that the electrolyte in the AGM battery is embedded into fiberglass mats (recombinant) layered between the lead plates... significantly reduces out gassing (valve regulated), and eliminates electrolyte loss and leakage.

The consequence of a lack of evaporative, degenerative, boiling, or outgassed leakage or loss of electrolyte is: No battery maintenance.

This is a consequence I can live with.

No more prying open battery caps. No more peering down dark little holes trying to see what the level is. No more judging if the reflection of the liquid is a correct indicator of level or condition. No more dancing around with Q tips trying to prevent any dirt from falling into the black holes... dirt that was hidden under the 3 per unit caps that could not be cleaned off the battery prior to removing said caps. No more hunting for distilled water. No more finally finding my battery hydrometer, only to find that the rubber bulb deteriorated and cracked apart on the squeeze and now I have battery acid all over my hands. No more breathing in sulfuric acid vapors while staring down into the battery. No more removing, power washing, wire brushing, sanding, priming, drying, painting, drying, and reinstalling oem battery trays from the mysterious leakage of wet cell batteries. No more replacing battery cables from corrosion at the battery terminals wicking inside the insulative jackets of the battery cables themselves. No more exchanging batteries every 3 to 5 years. All of these formerly routine chores were wrested away from me once I switched to AGM batteries, with the first switch occurring about 17 years ago. I find the forced retirement from those duties to be a tolerable consequence of switching to AGM.

Speaking of switch... if your truck sits for extended periods of time, consider some type of battery disconnect switch on the negative terminal. Just don't get the green dial screw type kind, such as what is sold at Harbor Freight... they are not rated high enough, and the screw can back out from vibration. I'm using knife switches, as shown below.

 

As I mentioned in the earlier post that you quoted, there is a ground connection on either side of the lower engine toward the radiator. Follow the battery ground cables down if you are unable to find them. Once you do, you will see how close you were.

Almost 4 years ago I lost all confidence in flooded lead acid batteries. I was tired of them letting me down and having to be swapped out too often. Even though they were prorated or replaced under warranty, that didn't remove the hassle of replacing them and possibly being stranded in the middle of nowhere while boondocking.

I took a leap of faith and bought some Northstar AGM batteries and never looked back. Even after sitting for 3 months, they are still fully charged. If they make it to 6 years I am even money and if they make it past 6 years I am money saved, time saved and no hassles.

I don't typically buy things because of the warranty, I prefer to buy them because of their reliability. Warranty doesn't mean crap to me if the part let's me down when I need it.

A list of AGM batteries that Y2KW57 put together is below.

AGM batteries is one of those things that you get what you pay for.

Link: AGM Group 65 Battery Comparison

 

I'll second the vote for Northstar AGM's. I run single in my boat where most people run two. More CCA's and RC than other brands in a given size. Batteries Plus sells them with their own branding for a little better price.
Also, have you checked your starter solenoid? The contacts can get burned up inside them and may cause some issues.

 

Northstar is no more.

Northstar was begun about 20 years ago by 3 executives and the chief technology officer of Enersys, who all left Enersys when they met a local entrepreneur in Missouri who was flush with hundreds of millions in cash from having just sold Contico Plastics.

This entrepreneur quickly realized that he had before him the brain trust of Enersys in the form of these four corporate refugees, so they set up shop down the street from Enersys and began Northstar, starting off with selling batteries for telecommunications.

A couple of decades and a couple of corporate restructurings and foreign acquisitions later, at Enersys and Northstar, Enersys grew bigger, faster, and was able to swallow up Northstar back into it's fold. So now Northstar is Enersys. Full circle.

 

Money ain't never wasted on new batteries,starter or alternator.

 

It seems the Odyssey Extreme is out of stock everywhere and can’t be ordered online. The local Batteries Plus store said their warehouse is out and not even available to back order.

 

Maybe the list in the link I provided above will allow you to find a suitable replacement if you are looking for an AGM.

Just before posting this, I performed a Google search for "group 65 odyssey extreme" and saw that Amazon and Advance Auto showed them as in stock. I stopped looking after those two sites.

 

Did you pull the starter apart and look at the brushes? I had a very similar issue that sure seemed to be the batteries even though they were less than a year old. Replaced batteries, took a trip out of town, and all seemed good. When I got back in town it started up again, pulled the starter and it was worn brushes. I wound up installing a very lightly used 2021 6.7L Powerstroke starter, and man was that the best upgrade as it spins over faster than I've ever heard a 7.3L spin!

 

A few updates.

Batteries were swapped at Costco for no charge. The Odyssey batteries were too expensive - at least for now.

I made the mistake of not testing the old batteries first.

I removed the starter and took it to AutoZone where it tested working. That’s not to say it’s not an intermittent problem but I didn’t want to ask them to test multiple times.

I checked the ground wires coming off the batteries and they both seemed clean (no corrosion) and were not loose.

I perhaps jumped the gun and bought the Denso starter from CNC. I also bought two grade 8 M10-1.5 x 40 bolts and lock washers.

I am starting to believe that the batteries don’t like sitting idle for 1-2 months without being charged. There is an aftermarket alarm on the truck that I assume draws some power from the batteries so that can’t help the situation.

I park the truck in a location where running an extension cord is not practical. Thus I think I need to look into a solar powered trickle charger. Unless anyone has any other ideas I’ll look online to see if anyone has suggestions on the best solar powered option.

 

Yeah, sitting for a month at a time without running doesn't work. Then it needs to be run a not to charge the batteries. I bought a solar charger off of fleabay but I do not think it is working so be wary of what you get.

 

Did somebody say Knife Switch?

 

To put a pin in this for future readers, I replaced the batteries with Costco standard lead-acid batteries, the starter with a Denso from CNC, and determined that as noted above the load on the batteries lasts for about 60 seconds from the time the key is switched in the on position.

I am starting to think that my issue was primarily not waiting the full 60 seconds to start the truck.

That said I suspect a worn (but not broken) starter and dead cells in my batteries.

I must say that starting the truck is a completely different experience than any time in the last ten years.

Thanks to all for their feedback.

 

I almost never wait for GP’s to time out before starting. Based on GP LED mod.

 

Soon as the WTS goes out my truck is started.