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Batteries

MrMarty51

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Remember to always have batteries load tested when you buy them. I have rejected a lot of batteries. At Rural King, they returned a whole pallet of batteries, because all failed the load test
Might be best to call or stop in a day or two in advance and have them put the batteries You've selected on a charger, allow them to charge for 24 hours, then, when testing draw out the surface charge before performing the test procedure.
At least that's the way I remember that battery testing should be done. LOL
 

Will L.

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Might be best to call or stop in a day or two in advance and have them put the batteries You've selected on a charger, allow them to charge for 24 hours, then, when testing draw out the surface charge before performing the test procedure.
At least that's the way I remember that battery testing should be done. LOL
By load testing how they sit on the shelf, you will know if they already are not worth having. Charging before you test when buying is like putting the burger under the heat lamp then checking if it is the right temperature. It might be 5 hour old burger that got to room temperature, but heating up before charging you won’t know. The parts store people are taught to always do it, so they don’t even know they are tricking you to buying one that has suffered a bit of damage.
 

WarWagon

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May have mentioned it before, the AC Delco batteries that came in my truck lasted for over 11 years, mileage was at 73,053.
IMO the entire point of this thread is IF a (specific) AGM type of batteries deliver any "value" for their additional cost. In mild climates with decent charging normal flooded batteries can clearly last as posts like yours illustrate. Yeah, AGM is not worth it for the majority in normal use IF total lifespan is the ONLY concern. Cost of 2 flooded batteries vs. cost of one AGM... Well the AGM had better deliver more than 2x the life for the investment. You wouldn't get an opportunity or even have a need to replace OEM batteries. :D

But that's not the angle of AGM marketing let alone reputation: AGM is marketed to be able to take EXTREME ABUSE.

Reputation has them lasting longer, but, as illustrated in the reduction of warranties not their goal anymore. A faster charging rate with higher CCA's is also a marketed advantage ... and sent many firecracker GM CS130's over the thermal edge of failure after one left the headlights on too long and discharged an Optima pretty deep. For example: To those that have had a OEM stupidly routed wiring harness run under the battery tray fail from corrosion or acid leak cost would favor an AGM even if the life is the same. If you got good cables I have always felt that the AGM's would spin a diesel faster than flooded in Colorado's colder weather, but, never measured it back in the day. (Offhand the 1988 OEM was like 750 CCA vs. Optima ~1000 CCA times two.) We did stare at the direct drive starter our of our 1988 6.2 that failed after getting 2 red tops... it flung a bar partially out of the commutator and started slow twice before it completely chipped/beat the brushes to bits. o_O We did ask if we had too many CCA's!

The battery piles I dived in had Optima batteries in it for ONE reason: The single cylinder air cooled diesel light plant(s) had run out of fuel and run the battery dead. (They had so many on the remote 24/7 project that the fuel trucks couldn't always keep up.) The fleet manager had discovered that the extreme vibration from the earth shaking and unreasonably loud diesel light plants would quickly destroy the plates and/or crack the case of normal flooded batteries yet wouldn't kill as many Optima Red tops. Still had lots of work putting vibrated out bolts back in as well as lamps, delivered by the pallet often, that were shaken to death.

Charging... I am looking at moving the converter(charger) on my RV because 20' of small #6awg copper between the batteries and converter is giving me a 1.0v drop during the AGM bulk charging phase and limiting me to about 25A. I should have near the 60A rating of the converter able to be dumped into the 50% discharged Deep Cycle AGM batteries per the battery manufacturer and maybe you need a bigger amp converter... (Then I have to look at it's 3600W generator abilities powering other things like the AC and bigger converter.) Fast battery charging vs. slower flooded cell charging: Something the RV designers didn't think about a lot let alone AGM options. "Converter fits here: as far away from the batteries and everything else as we can get it on this RV..."

Storage and self discharge: Battery disconnect switch and forget about AGM's for months. You need to charge flooded cell batteries every 30 days or so from self discharge. Infrequent use is an advantage if the parasitic loads are removed as to not kill the AGM anyway.

Page 23 of this technical paper illustrates the affect high temperature has on short battery life. My POV should be clear that our beyond extreme heat is a major problem even for the best of the best. (As well as Page 19 extreme amp charging in there 500A inrush current per 100Ah of capacity.)



Our 2008 Duramax that towed RV's all over the USA and Canada, eh, got around 88K out of the OEM Delco batteries but less than 1 year. 3/36 warranty = our problem. Passenger side battery that gets real hot from it's placement under the hood by the firewall was the one that died. As the diesel use AGM examples I posted did not deliver any better life, well, they simply cost more. ( I got to wonder if the factor of how close to the electrolyte boiling point of 203 - 240° F the battery temp actually gets matters. )

Delco batteries were known to commonly leak from the GM side posts. Last one that leaked for me was in a 2000 GMC Sonoma that I bought off the "new" car hauler with 0 days sitting on the dealer lot. (Sitting on the dealer lot can parasitic drain kill a battery.)

As a parts delivery we delivered lots of batteries and note Delco's are made in China. If GM could they would be the first to import complete Communist China vehicles. Not like GM isn't trying hard to do so.
 

Will L.

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@WarWagon a couple things from this, and if I misunderstand- sorry. Just want to clear up incase you or others do think what I here.

“A faster charging rate with higher CCA's is also a marketed advantage ... and sent many firecracker GM CS130's over the thermal edge of failure after one left the headlights on too long and discharged an Optima pretty deep.”

How fast or slow a battery can take a charge does not affect the alternator life - an alternator is ac current and any excess created power just cycles unused before the conversion to dc. If it was a dc generator that was unregulated, it could. It’s like the refrigerator using more power than your electric shaver- the lower power use shaver doesn’t have ill effects on the power companies supply generator worse than the refrigerator does.
All AGM batteries can accept faster or slower charge (higher or lower ampere) than a wet battery, but the voltage has to be more accurate. A dead Lead acid will take a charge from a simple AA battery (just have to have a very accurate meter to see it). AGM can not


“If you got good cables I have always felt that the AGM's would spin a diesel faster than flooded in Colorado's colder weather, but, never measured it back in the day. (Offhand the 1988 OEM was like 750 CCA vs. Optima ~1000 CCA times two.) We did stare at the direct drive starter our of our 1988 6.2 that failed after getting 2 red tops... it flung a bar partially out of the commutator and started slow twice before it completely chipped/beat the brushes to bits. o_O We did ask if we had too many CCA's!”

‘Better’ cables never add to any system, only poor cables take away from. Proper sized and condition cables with proper clean connections help all batteries, starters, alternators, lights, etc.

Larger than factory CCA (Cold Cranking Amps) batteries: [trying to keep this book to a few chapters]
More is better except:
1. Cost more
2. More plates in battery of same outside dimensions equals more CCA. This means less acid to cause a chemical reaction, and therefore a shorter life. Also, means it is more susceptible to freezing and over temperature failure (easier to freeze or boil a glass of water than a lake). Also more susceptible to plates shorting out against each other because they are simply closer to each other.
3. If your alternator and it’s wiring is not sized to the battery, that will cause the alternator to work more and wear it out sooner. This is close to but not the same as the first issue brought up. If someone left the lights on every Monday, yes you would shorten the life of the alternator, but if you did it with a wet battery instead of AGM, the wet battery would drain more power, and take longer to charge up to full. That alone would kill the wet battery sooner/ deeper (time and voltage) and cause the alternator to run longer than it would recharging the AGM, and the alternator dies sooner in that scenario also.

As to The extra CCA wearing out a starter from too much? No.
Take the “CC” - that is just a legal agreed temperature set so all batteries have a level playing field to advertise off of. It is not a real electrical term. The “A” is. Amps.
the Amperage stored in a battery can be infinite but lets say I have a big one rated at 1,000,000,000,000,000 CCA. If that battery has to be recharged I need the hoover dam to do it. But I could power my dome light from it and it will never make it any brighter or dimmer. It will just stay lit a LOT longer (like centuries).

The voltage change is what causes a starter to spin faster or slower- the small battery cables have what is known as voltage drop. (Dont really do this unless on a bench- truck wiring won’t like it.) Check your rpm while cranking with 12 volts and compare it to 24 volts By hooking up batteries in series vs parallel. The starter will spin twice as fast. Then use a 6 volt forklift battery- it will spin half its normal speed. In all cases the ampere load of the starter never exeeced the amount of the battery. The cca of a car battery is like the mha of a cordless tool or remote control toy battery- they just say how many total amps that battery can possibly have in reserve if charged at 100% to show either how long it will run or what maximum draw at one time is.
 
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