For those of you looking to upgrade the batteries in your LMM and want an AGM I found that Deka is now making one.

http://www.remybattery.com/images/products/9AGM48_AGM_Performance_Battery_MD.jpg

Specifications:

Cranking Amps 875
Cold Cranking Amps 760
Ah Rate (20 Hr) 70
Group Size 48/91
DIN Size H6


Dimensions:

Length 11"
Width 6 15/16"
Height 7 1/2"

Very Very cool.

I may have to pull the trigger on a couple of these this winter as one of mine barely made it through the cold last year.

I may have to buy some myself the factory batteries are crap there only 2 years old if I leave my truck sitting more than 2 days truck won't start

For those unfamiliar with the term AGM or just want to learn about batteries visit.
http://www.windsun.com/Batteries/Battery_FAQ.htm

Is my Cat a AGM battery?>

Is my Cat a AGM battery?>


I'm pretty sure they are not AGMs, they are flooded... they ARE however built to a rediculously rugged spec. with unreal CCA's

good because I was fix'n to ask what the heck AGM meant.....:)For those unfamiliar with the term AGM or just want to learn about batteries visit.
http://www.windsun.com/Batteries/Battery_FAQ.htm

I just put two Optima standard red tops in mine (Delco 7-year ones went belly up in 2 years as usual). The red tops were $148ea and have 1000cca.

I just put two Optima standard red tops in mine (Delco 7-year ones went belly up in 2 years as usual). The red tops were $148ea and have 1000cca.

I assume you used a group 34R. Did they fit without any mods?

I assume you used a group 34R. Did they fit without any mods?
I'll look. They took a bit of fitting - as the new funky cable ends barely reach, but with a bit of re-routing, they worked fine.

So, I see this 48 has the posts in the stock locations.

The only other benefit I see to the Optimas over this is having the side-terminals also. If anyone has a winch or stereo gear that they need direct-battery connection and do not want to bother the stock cables at all.

Other than that, the benefits of AGM are pretty equal between brands.

I just looked it up - it's their "34/78" unit:

http://www.1st-optima-batteries.com/Images/schematic_3478_op.jpg

But, their 75/25 model would work better:

http://www.1st-optima-batteries.com/Images/schematic_7525_op.jpg

Is there some feature of the charging cycle on out trucks that takes batteries out? Or is it just the Delco batteries are crap?

My '09 seems to go through a charge/float cycle that is very optimal for a flooded lead acid battery.

Has anyone got a track record to show the Optimas (or any other brand) last in our trucks?

Don,

It would appear that you know a little about batteries by your statement on charge and float cycles.

IMO, our trucks are tuff on batteries for several reasons

1) The do not start charging until some cycle at startup is done. I believe it is the glow plug cycle as it takes longer in the winter before they start charging. Not sure what GM found it sure appears that they don't start the charge until the glow plugs are done. If you watch your volt meter you will see it gets pretty low at startup and stays there for a while, I have seen it not start charging for over 5 minutes. And as I am sure you know the life of a battery is exponentially related to charge cycles and depth discarge. So this is creating a much deeper discharge cycle than a gasser would have.

2) The passenger side battery seems to really take the heat, literally. With is location near the turbo and the back near the firewall where little to now are moves I believe there is a lot of heat. This IMO is the reason so many have had issues with the passenger side battery failing and boiling over.

Is there some feature of the charging cycle on out trucks that takes batteries out? Or is it just the Delco batteries are crap?

My '09 seems to go through a charge/float cycle that is very optimal for a flooded lead acid battery.

Has anyone got a track record to show the Optimas (or any other brand) last in our trucks?
ALL flooded batteries are crap, in my book. I have owned all of the brands and they all start leaking at some point. It's not IF a flooded batt will leak - just WHEN.

Diesels have a lot of vibration and heat, which flooded batteries don't like EITHER of.

AGM batteries CANNOT leak - ever. The are hundreds of times more resistant to vibration, since there is nothing sloshing around inside.

So, if you add up all of the positives of AGM, they all point toward working with diesel trucks.

Odyssey is coming out with AGM group 48's this Spring also........

http://www.odysseybattery.com/

;)

Don,

It would appear that you know a little about batteries by your statement on charge and float cycles.

IMO, our trucks are tuff on batteries for several reasons

1) The do not start charging until some cycle at startup is done. I believe it is the glow plug cycle as it takes longer in the winter before they start charging. Not sure what GM found it sure appears that they don't start the charge until the glow plugs are done. If you watch your volt meter you will see it gets pretty low at startup and stays there for a while, I have seen it not start charging for over 5 minutes. And as I am sure you know the life of a battery is exponentially related to charge cycles and depth discarge. So this is creating a much deeper discharge cycle than a gasser would have.

2) The passenger side battery seems to really take the heat, literally. With is location near the turbo and the back near the firewall where little to now are moves I believe there is a lot of heat. This IMO is the reason so many have had issues with the passenger side battery failing and boiling over.

I have designed and produced some charging circuits, but I am far from expert on batteries - more book-learning than practice.


1) I can't believe that delaying charging by 5 minutes or so has much effect. Mine holds above 12.4 Volts even during that 5 minutes in winter, so it may not be rapidly charging the battery - but it's not pulling much out, either. It may actually be doing the bulk charge during that time to replace all those cold cranking amps, and it just takes that long for the voltage to climb. I'll monitor this with my EFI this winter to see how much alternator load it thinks it has during that time.

2) This is probably the major issue. In parallel battery systems when one fails it inevitably takes the other one with it a few cycles later. We could prevent this by monitoring the battery states individually, but that adds a lot of expense and adds more failure points - so I would not go there even if I was designing from scratch.

I wonder how the AGM batteries react to the heat? I'd imagine just like flooded cells, since it's the same chemistry. So unless the vibration is killing them I can't see the AGM paying off. I could be convinced, though, by folks with experience.

I can't see the AGM paying off. I could be convinced, though, by folks with experience.
I have 22 AGMs (Optimas) in play right now. I have killed two over the years, which were both my fault (10 amp charger).

My original one in my '57 Chevy is a 1998 model. Still going. I am sure it doesn't have the original capacity, but it starts the car perfectly.

Every single Delco battery (OEM) I have had in new vehicles have leaked and started hurting the positive cable(s). My last two just did the same thing - the original in my LMM. Just put the two new Optimas in.

In some of my muscle/classic cars, the battery tray alone is significanly more than the battery itself. So, I can't AFFORD to have flooded batts on the sheer possibility that they will leak. BOTH battery trays already had corrosion/rust starting in my LMM from those damn flooded batteries that were in there. My bad for not pulling the useless things out sooner.

Persuaded yet?

The passenger side battery seems to really take the heat, literally. With is location near the turbo and the back near the firewall where little to now are moves I believe there is a lot of heat. This IMO is the reason so many have had issues with the passenger side battery failing and boiling over.

I won't proclaim to a battery expert, but here's my theory why the passenger side battery boils.
Boiling occurs because of overcharge. If a battery is boiling, it was my thinking that this WAS the good battery, (until it boiled).
On my 2002, the ECM monitors the driverside battery. If all connections are clean, tight, and minimal to zero resistance, AND if both batteries have simular charge and discharge rates, both batteries will charge somewhat equally.
The driverside battery connection has dual cables in one, one routed to starter, and one to the electrical system at the underhood fuse block and the ECM. Maybe this dual cable connection causes poor connections.
If the driverside battery connection is loose or if this battery is defective, it doesn't charge as good as the passenger side, the ECM sees a lower than normal electrical system voltage, so the ECM drives the alternator harder than it should, and the good, passenger side battery over-charges and boils.

Modified, I am going to throw one kink in you theory. If the voltage is sensed at the driver’s side battery then it is being sensed at the battery cable not the battery itself as there is only one cable connected. So a bad connection at the driver’s side would indeed cause the driver’s side battery to be undercharged but not the passenger side to be overcharged.

Modified, I am going to throw one kink in you theory. If the voltage is sensed at the driver’s side battery then it is being sensed at the battery cable not the battery itself as there is only one cable connected. So a bad connection at the driver’s side would indeed cause the driver’s side battery to be undercharged but not the passenger side to be overcharged.
Besides, they are both connected together - constantly. There is no way the ECM could monitor one or the other without a switching mechanism that isolated the batteries.

In the newer trucks, and I don't know when they started this, there is a very large fuse panel on the firewall just beside the passenger batt. It has three large wafer fuses - 175a, 125a, 125a. One goes to the intake heater. Another goes to the glows, and another goes to the starter. I would imagine other things tap off of each or one of these, but I haven't traced them all.

So, there is only ONE cable going to each battery. They both meet up at the inlet of this fuse block. I'll see if I can dig up a pic.

Actually, the two batteries connect at the positive cable of the passenger battery. One cable comes IN from the driver's batt and one cable goes OUT to the fuel block.

The input to the fuse block is on the left side (buss bar) and the cable on the bottom right of the block goes down to the starter.

http://www.dieselplace.com/forum/garageimage.php?do=full&p=112457&d=1274280927

Here is the damage from those wonderful 7-year batteries:

http://www.dieselplace.com/forum/garageimage.php?do=full&p=112458&d=1274280984

I replaced my original batts in my LMM after 2 years as well. I bought the best Oreilys had. They are called Super Start Extreme AGM (150 a piece). They are yellow topped gray batts like optimas. 970CA and 785CCA. So there is another one that will fit in our trucks if anyone is interested, only thing is the posts are on the opposite side, but everything still reaches. These trucks suck for batteries. My volts are always low at startup.

Subscribing...

These trucks suck for batteries. My volts are always low at startup.

Subscribing...
Nothing is free. This is why these trucks are so drivable immediately after startup in any weather. There is, of course, the glow plugs and they are mapped in the ECM to start full and then taper down as combustion starts forming enough heat to take over. In addition, there is the intake heater, which uses similar gobs of juice to pre-heat the intake air. This is also mapped to start real warm and begin tapering off.

Both of these systems, in addition to the stereo, climate control, BCM, TCM, etc all draw more than the alternator can overcome - temporarily. You can watch the volt gauge slowly rise as the ECM ramps the plugs and intake heater out of the mix. Summer is pretty instant, but winter time - naturally - can take a bit longer.

I have a LMM with factory dual alternators, what does all this mean for me?

I have a deka in my polaris ranger....just a little over a year old...and the thing is dead....no draw when the ranger is shut off too.....

freekin thing was 145 dollars...

on the contrary, i have an odyssey battery (dry cell) on my ds650 since 2003...not one problem ever

Nothing is free. This is why these trucks are so drivable immediately after startup in any weather. There is, of course, the glow plugs and they are mapped in the ECM to start full and then taper down as combustion starts forming enough heat to take over. In addition, there is the intake heater, which uses similar gobs of juice to pre-heat the intake air. This is also mapped to start real warm and begin tapering off.

Both of these systems, in addition to the stereo, climate control, BCM, TCM, etc all draw more than the alternator can overcome - temporarily. You can watch the volt gauge slowly rise as the ECM ramps the plugs and intake heater out of the mix. Summer is pretty instant, but winter time - naturally - can take a bit longer.

? OK I understand what on the truck uses juice prior to startup, just letting guys know another replacement option.

I have a LMM with factory dual alternators, what does all this mean for me?

Yours will charge the batteries more quickly, and can probably keep up with all those heaters even on cold winter mornings.

Probably means nothing as far as battery life goes....unless diesail's point #1 is truly a major factor.

I have a LMM with factory dual alternators, what does all this mean for me?

Not much, you will most likely still have the same problems.

I have a deka in my polaris ranger....just a little over a year old...and the thing is dead....no draw when the ranger is shut off too.....

freekin thing was 145 dollars...

on the contrary, i have an odyssey battery (dry cell) on my ds650 since 2003...not one problem ever

The two problems with batteries that are not used everyday is self-discharge and a battery that is allowed to discharge completely for all pratical purpose is done. Your odyssey battery is an AGM and while it does self discharge it does so at only a rate of 2% a month vs a flooded cell that can be as much as 20% a month. So after 5 months of storage a flooed battery can be 100% discharged and worth nothing more than the lead in it. While the Odyssey is only 10% discharged and ready to go back to work. It is for this reason that it is very important to use a float charger on any battery that is being store for more a couple of weeks.

Nothing is free. This is why these trucks are so drivable immediately after startup in any weather. There is, of course, the glow plugs and they are mapped in the ECM to start full and then taper down as combustion starts forming enough heat to take over. In addition, there is the intake heater, which uses similar gobs of juice to pre-heat the intake air. This is also mapped to start real warm and begin tapering off.

Both of these systems, in addition to the stereo, climate control, BCM, TCM, etc all draw more than the alternator can overcome - temporarily. You can watch the volt gauge slowly rise as the ECM ramps the plugs and intake heater out of the mix. Summer is pretty instant, but winter time - naturally - can take a bit longer.

It is my opinion that the alternator doesn't even start until the glow plugs are done. I suspect that the engineers might felt that the load of the glow plugs was large enough that it could damage the Alternator so they wait until after the glow plugs do their thing to start the charging cycle.

It is my opinion that the alternator doesn't even start until the glow plugs are done. I suspect that the engineers might felt that the load of the glow plugs was large enough that it could damage the Alternator so they wait until after the glow plugs do their thing to start the charging cycle.
Good theory! They just let the batts take the hit and then top them off afterward. Probably quite true.

Moved to Electrical.

Well the Odyssey Group 48 is now available!!!!

Model PC1220
http://www.odysseyfactory.com/images/battPhotos/PC1220.jpg

good because I was fix'n to ask what the heck AGM meant.....:)
X2