kevinb120

On the lot it seems like the cars with the active anti-theft are always dead, the others are fine.

tmcolegr

This is the one I'm using

metroplex

The capacity of the Optima is about comparable to the stock Group 96R/40R flooded lead acid batteries. I don't see the benefit in using an Optima red or yellow top in a on-road car that uses the battery for a SLI application (starting, lighting, ignition). For off-roading or a boat, the Optima makes a lot more sense.

Martimus

One advantage I experienced with Optima batteries was survivability. I had a Red Top installed in an old Toyota 4Runner of mine. Without my knowledge the battery shifted to where it was rubbing against a pulley. The spinning pulley made a hole in the side of the battery the size of a quarter. Even with that hole the Optima battery lasted almost a full year before giving out (at the time I lived over 200 miles from the nearest Optima dealer). And when it did give out the Optima dealer replaced it and gave me a brand new battery with a full warranty FOR FREE!

metroplex

Well that's apples to oranges... The Optima is a Valve Regulated Lead-Acid Absorbed glass mat (VRLA AGM) battery so you could fire a 124 gr FMJ 9mm Luger bullet into the battery without acid leaking out. The standard batteries in our Stangs are Flooded Lead Acid Batteries (FLAB) so you can't puncture the battery casing without acid leaking out.

The other problem with Optimas is that they use an odd size so they don't fit properly in most applications like the trucks, vans, or Crown Vics without expensive brackets and adapters. The plastic tab/fins they include are a joke.

Martimus

Yea we all know the physical differences in batteries. The point was pretty simple... Spiral cell batteries can take more punishment and abuse and survive in conditions that would toast wet cell batteries in a New York minute. Is that worth an additional $20 to $50? Maybe not for some but it is to me...

metroplex

Actually the spiral cells waste a lot of space. There are voids between the spirals that could have been utilized.

If you want a smaller capacity battery for an additional $50, be my guest. Unless you are using it in a boat, off-roading, placed in a weird spot (passenger compartment, upside down), or NEED to ship it via air transport, it's a waste of your money. If the Optima were sized properly, it wouldn't have shifted out of place in your vehicle and rubbed against a pulley.

Martimus

Whatever! Personally I'd rather spend $110 on piece of mind that I know will last 5+ years than waste $75 on a crappy wet cell battery that'll be lucky to last 2 years in this *bleep*ing desert heat!

metroplex

High ambient temperatures are one of the things that kill FLABs and non-VRLA batteries. This is something the AGM batteries do better, but only slightly better. I'm not sure if you personally got 2 years out of a quality FLAB and 5+ years out of an Optima in the SAME desert environment, but I've seen only marginal improvements in lifespan from the Optimal/AGM batteries (less than twice the lifespan of a FLAB). There is an improvement, but it isn't something I'd spend over $100 for on a normal daily driver especially with a smaller capacity battery that doesn't quite fit right in my battery tray. A Sears Die Hard Gold lasted 9 years in my T-bird that had trouble with cold starts, so it'd take an average of 20-30 cranks before it would start. I used that car as a DAILY driver for those 9 years.

The Group 34 is too small for my Group 65 trays, and their wingtip adapter is an absolute joke. I am not going to spend $100 on an Optima bracket to use their $110 optima batteries. I can just buy an Everstart from Wal-Mart or a Pro-Cell from Meijer and get the same 3 year full replacement warranty 100 month pro-rated as any other battery these days.

Martimus

As I said before, whatever!

I've seen, so called, quality wet cell batteries croak in ONE year. And I've seen cheap batteries last longer. Warranties on batteries are great til you have to use them... and they're pointless when you're stuck somewhere at 2am with a dead battery.

metroplex

I've never had a problem with Sears Die Hard Gold flooded lead acid batteries. We've been stranded numerous times with MOTORCRAFT flooded lead acid batteries. They usually die before the 3-year warranty is up. However I hear the same number of anecdotal reports that factory Motorcraft batteries can last 7-9 years.

Optimas have a smaller capacity (as in ampere-hours) than the same sized flooded lead acid battery due to the wasted space found in the voids between the spiral cells. I've seen quite a lot of AGM batteries and Optimas that lasted only 3 months. It all depends on where you are using them and how you are charging them. Most regulators were not designed for VRLA AGM batteries so they tend to overcharge them in the summer and undercharge them in colder temperatures.

We can swap anecdotal reports until the cows come home, buy whatever you want since it is your car.

tom281

m05fastbackGT

I can't say this enough times fellas...use an automatic tender charger if your Stang isn't going to be in use for 10+ days.. Mine sits in storage all through winter and haven't experienced any futher problems since..

m05fastbackGT

Just out of curiosity, are you currently using the Sears Die Hard Gold in you're Stang ? and if so, what's the longest period of time you've let your Stang sit without running it ? I wasn't able to get more than 30 days out of any of my 3 Motorcraft batteries, until finally installing an automatic tender charger..

metroplex

My Stang currently has the factory Motorcraft battery. I haven't actually driven the Stang in about 60 days. I have the active alarm system and the Shaker 500, but it came with the smaller Group 96R Motorcraft. I start up the engine about once every 2 weeks, for roughly 10-15 minutes. My garage is at about 0F-10F right now, and has been consistently at 10-20F for the past month.
The last Sears DH Gold that died on me lasted 9 years in the 81 T-bird. It was about the same size as the battery in the Stang.

I did the math and idling the car for about 10-15 minutes should be enough to compensate for the consumption of the starter and for recharging the battery. Keep in mind we are dealing with small capacity batteries (50-60Ah) and the Optimas are no better (50 Ah for Group 34). I'm not too concerned about the engine oil since I plan to change it every 6 months regardless of mileage. I'm not terribly fond of relying on a battery tender. In a worst case scenario, an electrical fire from a malfunctioning tender/charger is going to cause more problems than a dead battery.

m05fastbackGT

I don't know if you would be willing to try this ? but being that you haven't experienced any battery failures in a span of two week periods, try letting it sit once for 3 weeks and afterwards try it once for 4 weeks and if you still haven't experienced any problems ? then we can definitely rule out the keep alive memory as the cause...From what I was told by a Ford field service engineer who inspected my Stang was that a fully charged Motorcraft battery won't last if it sits beyond 30 days because of the keep alive memory in which I still have no comprehension of what it's purpose is designed for..

metroplex

The PCM's KAM (keep alive memory) is a portion of the memory that will be lost if the PCM is no longer powered (volatile memory). KAM contains idle trim strategies, adaptive fuel table values (LTFT values for RPM / Load), and other various settings that are not stored in the individual devices/components. Every PCM used since EEC-IV has KAM. KAM should not cause a fully charged battery to completely discharge after 30 days. In fact, KAM should not ever do that since it wants to be Kept Alive. In addition, there's nothing in the electronic system that could safely handle discharging a 50 Ah battery. You'd need a hefty resistor to do that, along with large heatsinks to safely dissipate all of that heat.

70MACH1OWNER

My feeling on the battery tenders also. I also practice this running my cars that sit for about 20 minutes every 2 weeks thru the winter and have never had any issues keeping them charged up. When I run mine I run them at around 2500 rpm though. Just did both my stangs and 3 tractors on Friday night to get them thru this cold snap. Everything started and ran with no issues. I still believe guys having issues with their batteries in as little as 2 or 3 weeks just have bad batteries.
Scott

metroplex

I just went to start up the Stang after it was last started on Wednesday. Before I did anything, I measured the voltage at the center console powerpoint using a digital multimeter: 12.15VDC at an ambient temperature of 5F. When the engine is initially started, the voltage reached as high as 14.78VDC. The regulators are designed to increase the charging voltage based on ambient temperatures and demand (higher voltage when cold, lower voltage when hot to avoid overcharging/boiling).

m05fastbackGT

So in your opinion, what do you believe is the cause of these Motorcraft batteries going dead in less than 30 days ? I find it very difficult to believe that I had to replace 3 batteries in less than 6 months for going completely dead..I could accept that maybe one of them could have been defective but 3 of them ? and I also don't understand why a Ford field service engineer would recommend installing a tender charger if the car won't be in use for more than 10+ days..This is really getting very confusing and frustrating when nearly 2 years later, you still don't know what is draining these batteries after just sitting for less than 30 days, none of this makes any logical sense to me at all..Sometimes I often wonder if I had been better off holding on to my 93 SVT. Cobra I hope this doesn't sound like a dumb question but what happens with the K.A.M once a battery goes completely dead, is everything lost or is it still stored somehow ?