Comparing pros & cons Lead batteries vs AGM

MAXRPM

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trying to figure out besides being a sealed battery without liquid acid, what other benefits AGM brings, longer logetivity? Or what if anything does Lead batteries have any edge on AGM? Battery savvy here we go
 

nayr

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FLA last just as long and for automotive needs AGM's simply cost more money..

whole bunch of snake oil around AGM's, they are actually less durable and tolerant to abuse, so they are even easier to permanently damage than a normal FLA battery.. in the end Flooded vs AGM its still just a lead battery, chemistry is the same, the advantages of AGM's dont start being seen until you have an off the grid cabin that daily cycles the batteries for a decade or so.

The +$60-$100 more for AGM will return you no benefits other than a lighter wallet.
 
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Mongler98

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oh geeze, go search this topic, save us the arguments again!
long sotry short, go with what the car requires, charging issues with AGM and so on and so forth. read into it. variable charging, sinwave alternator outputs, proper charging, proper ventilation, there are a LONG LIST of reasons why not to and why you should.
just go with a quality battery that your car calls for. nothing else.
btw only 3 companies make batteries, ALL batteries are just off branded versions of these 3 brands.
DON'T BE FOOLED.

in before s'storm
 

MAXRPM

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oh geeze, go search this topic, save us the arguments again!
long sotry short, go with what the car requires, charging issues with AGM and so on and so forth. read into it. variable charging, sinwave alternator outputs, proper charging, proper ventilation, there are a LONG LIST of reasons why not to and why you should.
just go with a quality battery that your car calls for. nothing else.
btw only 3 companies make batteries, ALL batteries are just off branded versions of these 3 brands.
DON'T BE FOOLED.

in before s'storm
Cmon it's got nothing to do with the previous posting I did, I'm curious about difference of these 2 types of batteries, I'd like to put my recent experience between the 2, and pls chime in.

My passat came with the original lead battery, replaced it about 1.5 year ago, got it from Costco, passat was giving me issues starting appears to be the key was not electronically communicating when firing her up, I was actually planning to take her to the stealer for programming, (nothing wrong with battery just communication issues) so I decided to switch battery with Costco and I got me an AGM, car fired right up, communication appears to be on track now, locks right up and everything seems to be fine, this is why I was asking you guys, I heard from interstate battery rep, that AGM batteries are better for electronics than lead battery.
 

Mongler98

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i dont wknow where your getting your 100% inaccurate and BS marketing info dude.
12v DC is 12vDC
AGM and lead acid batteries are identical in every way save for one. the acid is suspended in a glass mat. if it tips over, it can't spill
still have the exact same chemicals in it other than the matt.
charging however is hit or miss. some cars (most newer ones) have variable charging rates and special sinwave formats for AGM's
you will kill an agm faster than a conventional, battery if you put them in the wrong sistuation.

go over to candlepower forums and battery forms. literally everything you want to know about the right way and the wrong way.
just put a quality lead acid normal battery back in it that is "rated marketing BS" for 5 years. costco batteries are eh,,,,
if its not guaranteed for at least 3 years, don't bother. 5 years life is MAX.
dude, just do some reading and don't take our word for it!
 

nayr

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I get FLA Duracells from Sams Club, they are just East Penn/Deka rebrands that are priced nice and cheap.. dunno what Costco is slinging.

AGM's only automotive benefit is for race cars that can get by with a little deka lawn mower battery for starting and save a bunch of weight without lithium money.. Thats my plan for my ALH Westfallia swap, I want both battery holders for house bank so the starter battery is going to be a tiny lil Deka AGM battery I can stash somewhere.
 
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MAXRPM

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Maybe my lead battery that I removed from my car was at edge of dying, and was not fulfilling the electronic needs. Who knows, but now my car reads the keyless start no problem,

I do not need to go to any other forum, this has been my forum for a long time and if I post something is because I expect to learn from members that are savvy as nd knowledgeable, if you get irritated by it, pls do not reply
 
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STDOUBT

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We need Herm in here!

Maybe my lead battery that I removed from my car was at edge of dying, and was not fulfilling the electronic needs.
Not having the voltage numbers, hard to say but
Maybe it's a VW thing, or maybe all computery cars do it.
But when my MKIV's batteries are pooping out, various, random anomalies tend to pop up in the electricals, even though the car "runs fine".
 

MAXRPM

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the yellow top optima in my tdi tacoma is over nine years old...ran it dead several times leaving the lights on with no sign of stopping.
Yes I had one of those in my caddy way back in the days and now that you reminded me, it lasted like 7.5 years I gave it for an exchange for a reconditioned lead battery, and the culprit turned out to be the starter, so who knows how long that battery would've lasted
 
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nayr

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Battery life is more dependent on where you live and conditions you drive in than the differences between AGM v FLA.. A person who lives in Florida, daily drives it and never does a cold start can often get 10y outta a Starter battery.. but take that same person, and same car, with same batteries to a less mild climate and getting 5y out of it could be a good job.

I used to get 6-7 years out of my batteries when I lived in the midwest, now I live in Colorado and its been 4 winters before a new battery.. Of the half a dozen cars I've had here in Colorado, not one of em had a battery last more than 4 winters.. AGM or FLA didnt matter.

When the battery in my Audi TDI went out, there was a ton of things that started acting wonkey.. the rear lift gate stopped closing, the infotainment system started cold booting, blind spot monitoring turned its self off, etc.. however it was still starting and going fine for at least a month with all those quirks before it finally refused to start.. put in an identical battery to the one I removed and suddenly all those grimlens vanished.. When you got a battery going out it acts as a big current sink and robbs other electronics of proper voltage, thats all that you had going on with your old dying battery.. probably had a bad cell internally and would never take a full charge, but could still start the car.
 

turbobrick240

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AGM batteries are supposed to do better in high vibration environments. The best lead acid battery I've ever had is the Delkor lead-calcium battery that came new with my Kubota L4400. It's been fully discharged a couple of times and is still going strong after 12 years!
 

nayr

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FLA GC2 batteries are used in golf carts without any suspension at all.. I'm sure they see significantly more vibration than the battery in your german car.

Even among rock crawlers and offroaders physical failure of a FLA from vibrational stresses is extremely rare.. And those guys still dont buy AGM's for their physical endurance, but for the high amp output they can do intermittently.. You can start to take advantage of AGM's strengths, instead of all its weaknesses, when you have huge loads like winches and air compressors for 37in truck tires you can get by with less using AGM.

in my leafsprung camp trailer that was like a paint can shaker on washboard roads had FLA batteries last longer than the AGM's.. Cheap AGM's wont take any charge abuse before they crap the bed.

Deep Cycling lead comes down to how thick the lead cells are, the bigger the cells the less damage they take when they go below 50% SOC.. but this is at the expense of peak current output, they are designed to take low loads for longer times than high loads for shorter times.. True Deep Cycle AGM's are only made by a couple companies, and they cost a small fortune for Rolls/Lifelie quality AGM, where for a tiny fraction of that you could pair up a couple cheap FLA GC2's for under $200, and get >230AH of deep cycle capabilities and throw that whole bank away several times before it equals the cost of just one AGM bank of equivalent size.

You also have recourse for restoring a FLA bank, drain the battery acid, refill with RO water, give it a long charge w/a desulfator, then refill it with battery acid and you can often recover significant SOC.. they also store better since they can ship and sit on shelf dry, so you know it didnt sit at a partial charge on a shelf for months/years, cant do that kinda stuff w/a sealed AGM.

Battery life all comes down to TLC, if you very carefully care for a battery and coddle it like your first born you can get em to go decades.. the mars rovers are proof of that.. but we're not driving mars rovers, our vehicle's are not coddling batteries it only uses for half a second to start. Your car is rather apathetic to your starter battery, its not charging it when its parked, or compensating charge voltage for battery temp, or maintaining environmental parameters to maximize battery life .. so buy the best quality you can get for the least cost, and thats almost always some form of East Penn/Deka FLA rebrand.
 
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jmodge

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For what it’s worth, when I worked at the city we had a lot of problems with the yellow tops in police cruisers and ended up replacing them. It might’ve been parasitic draw’s from computers and such. We didn’t have the same issues with Lead batteries, but many of those yellow tops went on to live useful lives elsewhere
 

turbobrick240

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FLA GC2 batteries are used in golf carts without any suspension at all.. I'm sure they see significantly more vibration than the battery in your german car.

I actually don't think golf carts are very abusive to batteries as far as vibrations go. They also have deep cycle batteries with thick, robust lead plates. My tractor however sees real, sustained vibrations when it's working, and it's heavy duty lead-calcium FLA battery has held up exceedingly well.

Battery life all comes down to TLC, if you very carefully care for a battery and coddle it like your first born you can get em to go decades.. the mars rovers are proof of that.. but we're not driving mars rovers, our vehicle's are not coddling batteries it only uses for half a second to start. Your car is rather apathetic to your starter battery, its not charging it when its parked, or compensating charge voltage for battery temp, or maintaining environmental parameters to maximize battery life .. so buy the best quality you can get for the least cost, and thats almost always some form of East Penn/Deka FLA rebrand.
I would agree, but I'd be careful not to lump all of the various battery chemistries in together. Obviously none of the Mars rovers have lead acid batteries. A buddy recently built an RV from an enclosed aluminum trailer with three solar panels on the roof. He was going to put in a gazillion pound FLA battery bank, but I told him about cheap, lightly used LiFePO batteries from medical devices (ventilators and such). Saved him a ton of weight on a trailer that was already just about maxed out.
 
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nayr

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yes I have 100AH of LFP in my camper w/650W of solar, 30lbs and supports a 30AH day in poor solar conditions, or 90AH+ in good solar conditions.. and as a backup my honda genset can refill it from 10% soc in 2.5h w/40A charge current til its full, no silly absorb cycles that are wasting solar gathering capabilities and input/output efficiency is nearly 100%

I calculated that off engine charging alone, I would need >400AH of FLA to achieve the same level of engine runtime.. and thats like nearly 300lbs.. so an order of magnitude of weight savings, on an already heavy tongue.

that battery has a 10y warranty on it.. handles abuse better and can get enough cycles to go decades with daily cycling.

however a nice Lifeline or Rolls lead chemistry battery, well taken care of with proper environmental and charge/discharge parameters.. can also last 10-25y pretty easy with heavy daily usage cycles, just not in an automotive environment with intermittent and inconsistent charging opportunities and massive temp swings.
 
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hopcarolina

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I just bought a standard lead acid battery. I talked to the franchise owner at batteries plus bulbs for a while. good info. take it for what its worth.

The AGM batteries are better lead and will take drain downs better. New cars with all the electronics that don't get driven very far or sit have issues and the AGM battery will help.

Costco sells interstate batteries that are branded for them. Not quality. They are Johnson controls and use inferior lead. 100% East Penn FLA batteries are pure new lead and are good quality. Its best to find out manufacture of the battery and the lead.

I built a Corrado TDI and wanted 1000 CCA for my AHU for winter cold starts. I built my boost lines before the battery and I couldn't come close to fitting a 850 CCA battery. UGH I searched battery group size, dimensions and bought the battery that fit my car (AGM are smaller for = CCA). I ended up getting a Group 75/86 Dual terminal 650 CCA from Advance (Johnson Controls used lead). Advance had 20% off online orders. I bought it for $63.00!!!! I have only hd in the car for a week drove it like 6 times. it has been doing just fine for $65! The X2 AGM battery at batteries plus bulbs was $285.....

It will probaly last two years... Fingers crossed
 

SilverGhost

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Battery life is more dependent on where you live and conditions you drive in than the differences between AGM v FLA.. A person who lives in Florida, daily drives it and never does a cold start can often get 10y outta a Starter battery.. but take that same person, and same car, with same batteries to a less mild climate and getting 5y out of it could be a good job.
I used to get 6-7 years out of my batteries when I lived in the midwest, now I live in Colorado and its been 4 winters before a new battery.. Of the half a dozen cars I've had here in Colorado, not one of em had a battery last more than 4 winters.. AGM or FLA didnt matter.
When the battery in my Audi TDI went out, there was a ton of things that started acting wonkey.. the rear lift gate stopped closing, the infotainment system started cold booting, blind spot monitoring turned its self off, etc.. however it was still starting and going fine for at least a month with all those quirks before it finally refused to start.. put in an identical battery to the one I removed and suddenly all those grimlens vanished.. When you got a battery going out it acts as a big current sink and robbs other electronics of proper voltage, thats all that you had going on with your old dying battery.. probably had a bad cell internally and would never take a full charge, but could still start the car.
I call BS on Florida. Heat is what kills batteries. Most customers in SoFLo are getting 18mo to 2 years.

I researched it a while back and battery manufacturers increase the storage life of batteries by "freezing" them.

Main issue why you replace batteries sooner in cold climates is reduced capacity when temperature drop WITH an increased load from thicker lubricants and higher accessory loads.

Jason
 

nayr

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Yes heat does kill batteries, but its not like under the hood is a necessarily cool place either, I go from triple digits in the summer to negative double digits in the winter..

I was talking about my experience w/owners in more temperate climates, the portions of the country where its like average 72F almost all year.. the kinda folks complain about the heat when it hits the 80's, and about the cold when it hits the low 60's.. like portions of SoCal and Flordia.. If your one of the lucky ones who lives in a climate that never swings more than 10 degrees off 72F Ive seen car batteries last a decade, enough times its not a fluke.. They dont see hot temps, nor cold temps.. it never has to bake on a 105 degree day cruising down the highway, and it never has to start a cold engine.. this life free from abuse quickly doubles or triples the lifespan.. just for example, I bought a 10yro Florida car once and it still had its original battery, the first time it saw freezing temps the battery gave out and the front windshield cracked..

and yes, Diesels in the winter are particularly abusive to starter batteries.. with the thicker lubrication, super high compression and glow plugs your diesel needs the most amps your battery can provide, at your batteries weakest.. a battery that might be fine starting the engine in warmer temps will hit the breaking point on a cold morning, and then go back to being capable of starting the car for months/years more in warmer temps.. a worn battery in a warmer climate will go far longer w/out anyone noticing it has a reduced capacity, whereas in the cold climate it will reveal its self right away.
 
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SilverGhost

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Problem in SoFlo vs more temperate climates is the humidity which means AC runs 11 1/2 months a year. You should feel the heat coming out of a condensor on a hot day!

But also from working in SoFlo mostly since 2006 the battery replacements overall happen more often here than other places I have lived/worked (Montana, Nashville, and NorCal).

But back to topic - VW used AGM in cars before Start/Stop systems and they were always mounted somewhere else OTHER THAN THE ENGINE BAY. Phaeton in the trunk, Touareg under spare tire and/or drive seat. Battery training SSP indicated weakness of AGM was less high heat tolerance, so they tried to avoid mounting them next to engine.

That said the new cars have some REALLY sophisticated heat management in the cooling systems that does seam to drop under hood temp a little. Maybe that combined with the additional strains on FLA from Start/Stop is why the AGM has been approved for replacement (note:no factory installed)?

Jason
 

Mongler98

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I'm calling bs on heat under to hood damaging batteries and also about this inferior lead bs.
Some have thinner lead plate mats bit that's how you get higher CCA by packing more rows in. Lead is lead reguardless. I raced my tdi with insane temps so hot that it peeled the clear off the hood and I do have a battery cut off so to shut the car down and start it up I have to get to the battery and even at the point of overheating the ahu I never once had a battery much hotter than anything else, cold enough to touch and handle but definatly not cool! The #1 killer of batteries reguardless or agm or other is discharge cycles that go under 50% of the batteries capacity. 5 years is typical life even if shelved for agm and basically same for normal acid batteries. I can see 10 years on a well maintained hut it's going to be a low capacity and living in Florida I'm sure it was dead, but had enough to start it.
 

turbobrick240

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Heat kills lead acid batteries. Everybody knows that. I remember visiting my grandparents every winter in S. Florida- when opening the doors to my grandfather's Lincolns and Cadillacs the interior temp would be around 300°, lol. Sitting baking in the sun all day long is brutal on batteries. If you have a climate controlled garage, then it won't be so bad.
 

Mongler98

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Heat kills lead acid batteries. Everybody knows that. I remember visiting my grandparents every winter in S. Florida- when opening the doors to my grandfather's Lincolns and Cadillacs the interior temp would be around 300°, lol. Sitting baking in the sun all day long is brutal on batteries. If you have a climate controlled garage, then it won't be so bad.
300 seems extreem seeing as coolant temp and engine temps wont really reach higher than 200ish with heat from the sun. 300f would definatly kill any battery, especially lead based ones.
I didnt mean to say that heat wont kill a battery, just saying that in most climates that with a tdi, 5 years is still a good life.
 

turbobrick240

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My bad. The IR thermometer I carried around at age 10 registered 333°. Kelvin. :D
 

SilverGhost

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Atlas comes with EFB+, but the replacement supersedes to AGM. None of the ones I have PDI'ed have AGMs from factory.

As I said - they avoided AGM in engine where they could, but do install them there if they have to.

There is a difference between a race car(or any car) that gets screaming hot for relatively short periods of time as opposed to constant heat for longer periods of time. Also I would wager a race car does not have full trim under hood - hood blanket, side skirts, belly pan, insulated engine cover, AC on full blast, etc. A lot more open air flow to dissipate heat I would guess.

Jason
 

Mongler98

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no hood blanket, fans on hard wires 100% of the time, no side skirts or belly pan, no insulation other than selective heat wrap on firewall, i race and autocross with ac on 100% of the time unless i have to keep my windows down like in PCA and CDC autocross events.
35 minutes of WOT track racing on a 95*F day with like 80% humidity with the AC on full blast and the battery still was able to be touched with no burning feeling. when i got back to the pit i have to feel it every time, also took thermal imaging back when i was doing that water injection and the battery was always one of the coolest parts of the engine bay.
 

SilverGhost

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What is the deal with those EFBs anyway jason, noticed across the board they've been failing really quickly on everything from the atlas to golf Rs? High electric loads and tight engine bays seem to be the common denominator from what I take it
I don't know if it's crappy quality (VW penny pinching is showing in a lot of things) or the battery is just not suited well enough for the start stop and the new generator load biasing. I think a proper deep cycle/starter battery would have fared better.

Jason
 

Mongler98

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Vw does not make batteries. They grab low end rebranded garbage. Still,
 
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