Recommended 12v charger?

[Ducky's Dad]

Interesting stuff... was anyone aware of Odyssey/DieHard Platinum AGM's claim that their plates were made from "99.99% pure virgin lead"?

I am aware of their claim, and had that discussion with Bruce Essig of Odyssey. Bottom line is that lead is lead is lead, as long as it has been properly recycled (emphasis on "properly"). The virgin part is just pure marketing hype.

Too, these particular AGM's require a long time (3 to 6 hours) in an absorption phase and at a voltage higher (14.7!) than what other makers recommend.

That seems to be a quirk that is specific to Odyssey, and I have also had that discussion with Bruce Essig. Northstar and Optima claim that theirs do not need 14.7+V. And an Odyssey 2150 Extreme can require more than 6 hours in absorption phase, depending on the input amperage of the charger.

Along with your excellent theory which includes an ever-increasing "idle" draw current and phantom loads,

Not really "phantom" loads, because we know they are there, but they vary by vehicle and equipment package. Each load can be very small but there are a lot of those small loads and they add up. Even Odyssey says that the only sure way to eliminate then is to disconnect the battery's ground or to install a kill switch. The biggest problem with that is that every time you reconnect the battery to drive the vehicle, the computer has to "relearn" a certain portion of your driving patterns to get all the sensors working. I had to smog test a vehicle two years ago that had been parked with no battery power for a while. Emissions system in perfect working order, but it failed the smog test because the O2 sensors were not sending the right data to the smog test computer, even though the truck ran fine and there were no codes thrown. Took 500 miles of miscellaneous driving to get the O2 sensors to pass the smog test.

these premium AGM battery types are not being charged completely... these need a 3-step charge profile from a microprocessor-controlled charger. Alternators alone will only take it to 80-85% state of charge and with what we know now about AGMs, this can also kill battery longevity.

The right alternator/voltage regulator combination can keep the AGMs at 100%, depending on driving patterns, but I am not aware of any mass market vehicles in the US that come from the factory with the ability to properly charge something like an Odyssey 2150 Extreme. The newer conditioning chargers are up to 8 or 9 steps, instead of the standard three-step profile. There is an extensive thread on all this under "what batteries do you recommend" (or something like that).
http://www.expeditionportal.com/forum/threads/146807-What-batteries-do-you-recommend

Odyssey/DieHard Platinum AGM's

Sears is phasing out the Odyssey line and their new Platimums are supposed to be coming from Northstar.

 

[rayra]

I'm well aware smart chargers have profiles for flooded, AGM and even LIPO. Marketing aside, I don't see how they can desulphate a AGM battery..

Do you think that AGM batteries don't still have lead plates? The 'AGM' fills the voids in a an otherwise 'wet' arrangement, lead plates / sheets still form the core of the battery. It's still a lead-acid battery technology. And thus desulphination still works.

 

[Ducky's Dad]

And thus desulphination still works.

Do you mean desulphonation (aka desulfonation)?

WHAT IS DESULPHONATION?
The removal of sulphur, such as in the sulphur that naturally occurs in petroleum products. Diesel, to name but one.
Removing sulphur from diesel fuel cuts air pollutants that contribute to acid rain (sulphuric acid).

Not the same as desulfation.

15.12 Desulfonation. Mechanism of protonation
100-175 oC
with aqueous acid
This desulfonation is the exact reverse of the sulfonation process by which
the sulfonic acid was originally made.
Removal of the relatively volatile hydrocarbon by steam distillation shift the
equilibrium toward hydrocarbon
Sulfonation is unusual among electrophilic aromatic substitution reactions:
- its reversibility
- Ordinary hydrogen (protium) is displaced from an aromatic ring about twice as
fast as deuterium+

http://staff.guilan.ac.ir/staff/use...r_repo/file/Org_Chem_2_Ch15F_2 (PPTshare).pdf

Any chemists out there who would care to elaborate?

 

[4x4junkie]

I have done a fair amount of research and kicking things around with manufacturers and mechanics, because of the battery issues I have had over the last few years. The consensus seems to be that it is not a self-discharge problem as much as it is a parasitic drain problem. All the electronic crap on newer vehicles has increased the parasitic drain to the point that even a daily driver sees a significant drain that is not always replenished during a short commute. Do that over a long enough time and you get a degree of sulfation, and most drivers can't even spell sulfation. The sulfation can be cumulative in some situations and can lead to premature battery failure. The obvious culprits would be clocks and alarms and USB cell phone chargers that are left plugged in all the time. Nobody in the general public seems to realize that things like proximity starters (in some cars) are always looking for a ping from a local "key," and the car's computer is almost always awake to some extent. Even on vehicles in which the computer is ostensibly designed to completely shut down, there is often a much longer delay than in the past. When you lock the car and walk away, it might take the computer ten minutes to power down. I have been told that some alarm systems will keep the body module awake, even when the alarm is not activated, because the body module is programmed to look for a ping from the alarm sensors. I recently learned that some power programmers (like the Edge Evolution in my Dodge) add a tiny bit of parasitic drain when they are left plugged in to the OBD-II port, and I generally leave mine plugged in because it is also an eight-parameter programmable gauge pod. It shuts off about thirty seconds after I remove the key, but even with the display off, there is a drain. The National Luna battery monitors that I just got seem to add a bit of parasitic drain, even when turned off. All this little electronic crap adds up.

That definitely would make sense in the bigger picture overall, however it doesn't explain why I've seen batteries fail quicker in my own two rides too (the other is a '94 Ranger pickup). I've owned both of these rigs long enough to see this trend in shorter-lived batteries is fairly obvious. I've not changed or added anything to them that would create a parasitic load on the battery (new alarm, chargers, cigar plugs w/led light on them, etc.).

I can get the batteries to last a good while if I give them a little attention once in awhile (the ones in our RV are a good example), however it didn't used to be like this.

 

[Ducky's Dad]

it didn't used to be like this.

Very, very true. As Dwight D. Eisenhower once (allegedly) said, "Things are more like they are now than they ever have been before."

 

[comptiger5000]

It's interesting to see people looking down on Deka, as they're made by East Penn, who I've generally seen to put out better batteries than the standard JCI and Exide units (closer in quality to Odyssey and the other high end batteries). Personally, I've had a Duracell branded East Penn AGM in my Jeep for about 4 years now. It's been charged every once in a while if I drain it a bit and I'm not going to drive the Jeep right away, but 99% of the time, it's just charged by the alternator (which does put out plenty of voltage for a good absorb stage and it's also temp compensated with a sensor under the battery). After 4 years, it still holds plenty of capacity and is doing its job just fine.

I do definitely have some parasitic drain on top of the stock ECU and such as well, although it's fairly rare that the Jeep is parked for more than 24 hours (only happens a few times a year). Stock bits (ECU, alarm, etc.) are about 40 - 50 ma of drain. I'm probably at about twice that, factoring in the trailer brake controller and the blue sea USB outlets.

 

[Ducky's Dad]

I have no direct experience with Deka batteries, and there are not a lot of Deka dealers in So Cal. When I sorta wanted to buy one, my usual purveyor talked me out of it, even though he had one in stock. I suspect that one reason Dekas are dissed might relate to the blowout sale they had two or three years ago when they changed the color of the case and were selling Grp 34 AGMs for $100+, just to clear the inventory (I tried to buy then, but couldn't find any, got in late to the party). That may have given Deka an image as a low-budget alternative to the big names. From what I read, a lot of those Dekas went into rice rockets with huge subwoofer systems and that crowd is known to abuse their batteries with probably minimal attention to recharge regimens. One of the dealers I use has a pretty constant supply of used Optima Yellows that came out of that kind of service, some are good and some not so much.