The batteries in my F-250 keep going dead over the space of a week or two of non use. So, that means when it's cold and I forget to put it on my trickle charger (which is nearly 100% of the time, same with the block heater) I can't start my truck. In general this isn't a huge deal, unless I need to get somewhere. It's happened twice in the past few months. My charging system is just fine (new-ish alternator putting out about 14.4 VDC), and the batteries take a charge just fine, they just don't keep it. It could be some sort of parasitic load I haven't discovered yet.

With all that said, I had the comptroller dig up the receipts for the last two Diehards, which I bought at the Redmond Sears just over 7 years ago. So, it's time for new batteries in any case.

Costco sells Interstate group 65s for $99 (I need two for my 7.3L diesel). Walmart sells what I think is a Johnson Controls (Everstart Maxx) with a 3 year warranty for $88. I think I can get an Everstart AGM for $150 or so from Walmart, but not sure it's worth it, there were no AGM batteries at the Monroe WM yesterday. I don't have any gizmos on my truck with the exception of my winch which almost never gets used.

So, a few questions.

Any of you guys battery resellers? I'd rather throw cash at a WaGunner than some random box store.

Is there a case for AGM batteries? This truck is my daily commuter, except I've been working from home for a year due to Covid, and expect to continue to do so into the foreseeable future. This is also why the battery isn't getting a charge, the truck basically just sits unless we're running errands, which is about every two weeks.

Are there better places to buy batteries?

My 1998 Suburban with a 454 and Red/Yellow top Optima batteries was not a good combo. I too have a slow parasitic drain and a big engine to turn over. Switched back to lead acid and have been happy.

I wanted top/side post batteries so I ended up with 2 year warranty batteries which isn't what I wanted but it what was available to me at the time.

I have had good luck with Duralast Gold from Autozone. Had a battery last about 12 years. I only replaced it as a precaution not because it failed. And that battery was drained to dead several times.

AGMs are not my choice for my diesel truck or my equipment.

Lead acids are great for rigs and equipment that sits around.

I use AGM in my boats for small (60 h.p.) outboard and inline inboard motors. They are supposed to be better for things that get bounced around a lot and I've had good luck there. Ran Diehards in my truck for years but somehow Sears pissed me off awhile back and I went with Interstate and have had very good luck with them. Had one go soft on me after about 5 years once, and the guy didn't prorate, just swapped me a new one, no questions asked. Also use Interstate deep cycles for electric trolling motors and the have always given good service.

Last battery in my truck was autozone gold top. It lasted 10 years. When I looked at a replacement they wanted twice as much as costco, which I believe are interstate

My diesel van sucks because it takes two different battery sizes. Last time I replaced them O'Reilly was the only place that had the thinner one. So far so good, although I don't drive it much and always keep it on a charger

The Peterbilt has four group 31 batteries that I also always keep on a charger. Those are Exide and came with the truck when I bought it 8 years ago. They are holding up well

Flooded batteries, 800-850 cca, check cables and terminals REALLY good.
7.3 should start without any issues at 20 degrees IF glow plugs, and/or grid heater works AND starter spins fast enough to build high pressure oil for injectors to start spraying.

Johnson Controls is the way to go, IMO.

Both Interstate and Everstart MAXX are made by Johnson Controls...

AGMs are still SLA/VRLA, just laid out a little differently with different materials.

The general advantage of AGM is lower resistance, which means you can get more current during both discharging, and charging...

They will recover faster after a large drain, and can deliver more current than a traditional SLA. This falls directly in line with Diesel engines in cold environments.

I would go with Costco, because they have (had?) a 42 month full replacement warranty.... and will allow you to essentially swap batteries every 3 years, at no charge.

If you're consistently below zero, and it's sitting for any stretch of time, the AGMs can be a good choice, but I've run traditional SLAs in all my diesel trucks, even my 5 ton, and started them up with no issues...So, they're not necessary, but have their advantages. If I can start a 855ci 14L Cummins, with no ether and no glow plugs, at 30*, with 2 Group 65s, you should have ZERO issues....

Optima batteries, while owned by JCI, moved manufacturing to Mexico years ago, and they haven't been as good as they once were. They're also a little smaller, and tend to have lower CA/CCA/RC for another AGM battery of the same battery class.

Thanks for all the replies guys. It sounds like I should be fine with a couple of Walmart's Everstart Maxx group 65s, although I'll call Costco about their warranty. Don't mind paying a bit more for a longer warranty.

If it is a parasitic load then new batteries won't help. It isn't terribly hard to determine if you have a draw on your batteries after you shut your engine off (and after all accessories power down), you can see it with just a multimeter placed between your cable and the battery. Here is a good video of it but you don't need to scan tool he uses, a multimeter would do the trick too, you just won't have a graph of it.

Have you checked and see if the outer case of the battery is causing a drain? It might sound weird but if the outer case is dirty, they can cause a drain and you'll constantly have a battery that is dead after sitting a while.

You can clean it up and it should hold the charge afterwards.

Check this:

If 7 years old, they may be going (or one going, but it saves grief to change both). Get them load tested outside of the truck and if they are bad, there is probably no parasitic capacity.

AGMs do have some perks, but there are some issues if your charging system is designed for traditional lead acid, which can have a higher fixed float voltage (fixed maintain voltage after charging is detected as completed).

Technowienie pointed out the less internal resistance of the AGM, which is good in all cases except when the battery is fully changed and your float voltage is designed for the higher-resistance traditional lead acid. The voltage potential normally eaten by the lead/acid internal resistance is adsorbed and overcharges the AGM in this case, reducing life. Conversely, the lower internal resistance allows the battery to recover more quickly during short drives.

On our Audi, you actually program what type of battery tech is and it will issue different charging curves. Your truck may have an option to choose the type/capacity or can learn the battery.

Only other note is if the batteries are in the Cab, I would buy AGMs. The women and her daughter who died in Florida two years ago in a Porsche, died from sulfuric acid in a lead acid battery that was being more rapidly charged with the AGM curve and didn't have the vent tube attached.

TL;DR-AGMs are more expensive and better unless your charging system has a higher fixed voltage float. Use a battery charger that specifically calls out AGM compatible if going AGM route. Traditional lead acid you won't have to worry about these issues and would choose them unless the batteries were in the cab.

To add to that, since we're doing a deep dive...for general information....not directed at you ducky

Most people blame AGMs for burning up alternators, or even tossing belts....

This isn't true, per se.

Most models don't go with an AGM from factory, they end up replacing it when the factory one goes bad, or when the 1st replacement goes bad, so, figure 7-10 yrs into the life of the vehicle....with 80-100K depending on driving habits.. This usually happens because they're told an AGM will fit their usage, which is usually either lots of accessory usage with the vehicle off (excess drain) or infrequent use (low self discharge rate), OR they're upsold into thinking it's the latest and greatest and they gotta have it..

So, they buy a fancy new AGM.. and a week later, their alternator dies....

AGMs, again, due to lower internal resistance, can absorb a crap ton of juice, very quickly. So, some guy drives his truck once a month, or uses his dome light as he does paperwork in his car, and runs the batter low.. He's still able to start the vehicle because of the AGM design, and now you have (on average) a 60A alternator, with a battery that can pretty much take as much as the alternator will give it.... and if you have components that are already not working optimally, like, say, an older alternator... well, what happens when you demand 100% output from something when it's not in the best condition to begin with?

Same deal with belts. The alternator creates resistance to spinning when it's under load....crank that load up to 100% and that belt that might have chirped for half a second on startup is now squealing like a stuck pig, or the cracks that were forming decide that the added stress is too much, and decide to no longer stay in one piece....

AGMs have their place, and they do have better characteristics, but if you're not using them in a way that takes advantage of those characteristics, you're pretty much wasting money, IMO.


I like AGMs in diesels because starting a diesel takes a LOT of juice...

Glow plugs can draw 200A, and cranking over a big 6-7 liter diesel with 15w40 in winter is like shoving a wooden spoon into molasses, and the extra couple 100 RPM or so can make a big difference on older trucks... So, not only can the batteries generally deliver more juice, for a longer time, they recharge quickly as well.

Think of it as a 5 gallon bucket. One, you drill a 1/4" hole into... The other you drill a 1" hole into.. Both hold the same amount of water, but the one you drilled a 1" hole into, you can get more out of, quicker, and you can fill it back up quicker, as well.

Batteries in diesel trucks, when set up in a parallel configuration, need to be replaced at the same time. Batteries want to self equalize, they want to be at the some voltage, so the new battery will constantly try to charge the old battery, bringing its state of charge down as well.... and you'll have 2 crap batteries before you know it...

Color me stupid, but I had a pair of Costco Interstates put into my truck in 2017 when I picked it up from Dad.
Flash foward to Feb 2019 and I noticed the batteries not cranking over very fast. So I replaced them again.
A month later, same thing, slow turning over, barely starting down here in Texas. So we get home in mid March and the truck wouldn't start again. (Fortunately we were HOME by now) I tested the batteries and they were putting out 13.7.

Googled the issue and found out it most likely was the starter. So there I am in MT, with a lift I couldn't use because the truck was sitting in the driveway dead.

I crawled under and proceeded to replace the starter. Let me tell you, it wasn't fun, especially that blind bolt up top that required a mirror to insure I was starting it correctly.

The starter was the culprit, cranks really super now.

There are direct drive, and gear reduction starters.

Direct drive starters weigh a ton, but can handle extended cranking.

Gear reduction starters weigh about half as much, use a smaller motor with added gears, and can't handle extended cranking but boy do they spin over quick...

In my best Johnny Carson voice, "I did not know that!"