When to replace a battery?

Joined
Jun 5, 2003
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Location
Apple Valley, California
The Battery in my Jeep is a Deka Intimidator AGM. Rated @ 775CCA. My tester shows that it can only put out 625CCA. Still plenty to start the Jeep. At what percentage of CCA loss should it be replaced? My tester says good,recharge and replace depending on it's mood.
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Cold starts are not a thing here in the Desert compared to other places. 28F is about as cold as it gets here and now that we are going into spring I won't be seeing any temps near that.
 
You go by CCAs to determine if the battery is bad? Have you tried doing the load test with carbon pile to see if the voltage is above 10 V?
 
When the wife tells me that her car was slow to crank, I send the car directly to Advance Auto for one of their batteries using a promo code.

Seems to be every 2-3 years down here.

If I have time to mess with it, I'll get one from Wally.
 
I think it depends.

If you're spending time in the back country where failure to start would be a major problem, then travel with a buddy (and booster cables), or keep that battery fresh.

If you only drive around town or on long highway trips, I'd run it 'till the battery fails to start the Jeep. My rule of thumb is "one no-start and it's done" unless there are extenuating circumstances, such as left the lights on or something like that.
 
I am in a similar situation. My battery is a 96R 590 CCA but is only testing at 470 CCA with a full charge. The voltage still comes up to 12.7 after the surface charge is bled off and the hydrometer has all cells reading on the low side of green. It seems to crank slower now than before and once after sitting for several days it started but some dash lights were on for hill assist and airbag disable which cleared when I shut it down and restarted. I also suspect my charging system is working harder then it should. At least once a week I put the slow charger on it overnight but I really need to replace it before it leaves me in a parking lot at night with all the stores closed or ends up killing my voltage regulator. I have been having a hard time finding a fresh battery in my group size, all the ones on the shelf have 01 or 02 month codes since this mess started no new battery stock. As an aside it is the factory original battery in a 2012 Fiesta so I cant complain about longevity.
 
Originally Posted by samven
I am in a similar situation. My battery is a 96R 590 CCA but is only testing at 470 CCA with a full charge.

As an aside it is the factory original battery in a 2012 Fiesta so I cant complain about longevity.


Go to SAMs they have a battery clearance, group 34 AGMs are $98, don't worry about the age, they are an inch longer and taller but same width
but can be made to work with some effort (check your battery area first to make sure you can rig up a different retainer)

I almost never use the OEM size in any of my cars if I can avoid it

Good luck
 
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With respect to AGMs the red top POS ones used to half-fail on me after a year. I drove over a year with one that slow-cranked but always started. But, the radar detector would go into a weird self-diagnosis loop. I should have, and eventually did, go to an X2Power AGM.

FWIW, the HF battery analyzer won't condemn a battery until 50% of CCA. I think that's too low, and you'll definitely hear it.
Nowadays, a DMM with min peak voltage capture I think is a pretty good tool. You're loading it with the actual load.
 
Deka Intimidator's did poorly when capacity tested in PSOC( partial state of charge) deep cycle duty by practical sailor magazine.

But Your jeep is not deep cycling it so it their testing relevant? Can't prove it either way. not without actual experimentation and data collection for comparison.

Odyssey AGM are considered among the best available AGM's.

Here is their 'conditioning' procedure:

https://www.odysseybattery.com/documents/ODYSSEY_Battery_Reconditioning_Charge_Procedure.pdf

I'd perhaps not use quite as high an amperage source with an Intimidator , but use at least 30 amps per 100Ah of capacity, and monitor it for excessive heat build up. Just keep it under 100F. The temp will help dissolve sulfation, but this does not mean get it to 150f while laughing like a maniac.

If you can actually accomplish the proper recharge according to their procedure, i would be surprised if your conductance tester's results does not improve markedly.

Lifeline AGM are considered the top dog of Deep cycle AGM battery manufacturers. They have a different reconditioning procedure.

Scroll to page 21.

http://lifelinebatteries.com/wp-content/uploads/2015/12/6-0101-Rev-E-Lifeline-Technical-Manual.pdf

keep scrolling for their 'deep discharge' recovery procedure.

Both procedures require a capability your existing charging equipment likely does not have.

I have performed the Odyssey procedure on my Northstar AGM( sold as X2power at batteries +) a few times, and while I don't bother with conductance testers, the procedure did improve subsequent times to reach full charge, and the voltage retention in deep cycle duties thereafter.

the Lifeline procedure requires 8 hours holding the battery at 15.5v after a normal full recharge, which means holding their battery at 14.4v until amps taper to 0.55 of the battery capacity measured at the 20 hour rate.

Lifeline is the ONLY AGM manufacturer to recommend voltages this high. UP to you whether you care to release some of the gas of your Deka, but one significant overcharge is not going to 'dry out' an Agm, and the vents do not forever remain open once their psi rating is exceeded, so disregard any online BS you might have read claiming that.

Since your equipment will likely not be able to attain the amperage listed by Odyssey, nor hold 14.7v as long as they say, that does not mean that leaving the headlights on until the battery falls to 10v and then using whatever large amperage charging source you do have, will not be somewhat effective in improving the numbers your conductance tester spits out.

Just putting a 95% charged battery older battery on a smart charger does not have the same effect as discharging the battery fully and then instantly putting it on a charger, getting it warm to perhaps almost hot with a higher amp charging source applied for longer., and then preferably hold 14.4 to 14.7v until amps taper to less than 0.5. is a very valid procedure, and can take 12 hours for amps to taper to that level on a sulfated battery

Perhaps tapering to 0.35amps @ 14.4 to 14.7v would be better for your group size battery.

On deep cycle batteries, they condemn them when capacity declines to 80% of new. But this condemnation is designed for blue water sailors, who can't just run to the store and get another, or might notbe able to get a quality battery at whatever port they next visit.

Don't know of a specific CCA reduction condemnation threshold. carry a jumper pack and when it fails, see what your conductance meter says of the failed battery.
The data would be useful to all of us.
 
The article you are referencing did indeed say the Deka AGM battery was no match in comparison to other true AGM batteries like Lifeline, Odyssey or Northstar... The article also made a good statement that AGM does not mean a battery with that sticker on it will be up to 700, 800 or 900+ deep cycles to a 50 percent DOD... It is what inside that AGM that matters and in that article it mentions exactly what you said about the conditioning process and proper recharging process.
 
BBhero,

I've got tons of experience cycling lead acid batteries, and lot of tools to measure amperage voltage, count amp hours and watt hours into and out of lead acid batteries, and measure battery temperature, alternator temperature, and temperatures within plug in charging sources. I have also converted ALL my charging sources into having manually adjustable voltage. I can spin a dial and watch the amperage change, as well as the temperature of the charging source, and how it things change at different state of charge and different states of battery health and different battery temperatures and of course different batteries too.

While ithis was not always true, I no longer post anything I don't have experience with, unless I say I do not have experience with this, but read...... effectively parrotting what could be false or misleading or incomplete information.

When discharging I can see how much amperage over how much time has been drawn from the battery, and I can see how long it takes it to reach true full charge again, and again, from different states of charge at different temperatures with different batteries as they age.

I read everything I can on the matter, and the Marine guys, who push both their large battery banks and charging systems to the absolute limits not only in a quest to have enough electricity for that trip, but years worth of trips from teh same batteries, obviously have established those limits more so than any regular contributor on an Automotive forum, however intelligent they might be in their respective fields/ areas of expertise.

I keep remembering the times many years ago when my understanding of how batteries charge, how charging systems work and how to get good service life from lead acid batteries was severely lacking, so I can also easily see when others understanding of such systems is also lacking, much as anybody who has a firm grasp on any particular subject/area can see those who do not, by the words they type or say.

A lot of my knowledge does not come from words written on paper or cyberspace or theories from a textbook, it comes from questioning them. wanting to understand them, and this requires performing experiments, requiring tools and situations where they can be tested.

When the result is not as expected, one investigates why,perhaps finds an actual issue, like a poor connection or a fault in their understanding of how it actually works. The lessons learned are invaluable.


Not having control of the voltage regulation of any charging source, is very frustrating for me, and In many ways I wish I could go back to being ignorant of it all, and just replace batteries more often.
The automatic' smart' charging sources throwing the green 'full charge' light is a joke, when one has the ability tools and desire to actually confirm a true full charge.
Seeing automatic charging sources fall so short time and time again, and then trying to get them to actually complete the job their marketers claim it can do, but cannot, is even more frustrating. Then coming here and seeing praise for charger brand A or B, when one knows them to be truly deficient in their ability to achieve a full charge, is even more so.

But Ignorance cumulated over time, killing batteries prematurely, and when not exercising battery warranties unhonorably or dishonestly, that becomes significantly more expensive than actually treating the battery better, and this is accomplished by better recharging to a true full state of charge, often.

Verifying a true state of charge whether by a hydrometer or ammeter and perhaps a columb counter, a device which needs regular calibration and rezeroing, which is accomplished by the hydrometer or the ammeter with the battery held at higher voltages, becomes paramount.

Now a car starting battery actually has a pretty easy life, compared to any deep cycling lead acid battery, and massive steps to insure regular true full charges are nowhere near as beneficial to a starting battery as they are to deeply cycled batteries, but lessons learned in deep cycling are applicable to the easy life of starting batteries and life living chronically undercharged, as most every automotive battery does, yet still can start the engine in come cases for 6+ years.

but automotive forums are filled with bad, incomplete or downright false information regarding lead acid batteries and their proper care and feeding.

Its a bit shocking when ones speedometer says 60mph, one GPS says they are dong 60mph, exactly, The milemarkers on the freeway click by precisely every sixty seconds, and some haughty self important internet expert says 'your wrong, your not doing 60mph at all, because it goes against my incomplete understanding of the subject.'

So I am going to go back to lurking and rarely participating.
I told myself this last year, but foolishly have come back and tried again to help enlighten people on a subject I am intimately familiar with and gain more experience in each and every day, only to regret it.

I wasted too much time relating actual data and experience and trying to enlighten people here on how to properly recharge their Lead acid batteries for maximum longevity, and very few people seem to actually attempt to understand it, preferring instead to have their incorrect beliefs repeated back to them, like how one seeks the news channel that promotes their political views and insists the 'other side' is always wrong, no matter what.

So I have a few more posts I am going to reply to here, and then take a vacation from here and contribute little forever after.
 
Originally Posted by bbhero
The article you are referencing did indeed say the Deka AGM battery was no match in comparison to other true AGM batteries like Lifeline, Odyssey or Northstar... The article also made a good statement that AGM does not mean a battery with that sticker on it will be up to 700, 800 or 900+ deep cycles to a 50 percent DOD... It is what inside that AGM that matters and in that article it mentions exactly what you said about the conditioning process and proper recharging process.


Not entirely sure of why the Deka Intimidator line would be compared to other deep cycle batteries. Batteries are designed differently based upon their intended use. It's pretty clear that the Deka is intended to be an SLI battery. The fact that it is AGM is primarily salient to the mechanics of recombination under charge, and electrolyte quantity/management in the cells. AGM does not imply deep cycle or vice versa.

https://www.eastpennmanufacturing.com/east-penn-reveals-deka-intimidator-tm/

Quote

The Deka Intimidator's technologically superior AGM design lowers resistance, increases power and eliminates acid spills, leaks and terminal corrosion by utilizing highly micro-porous separators to absorb electrolyte. Eliminating the need to add water, the Deka Intimidator's flat plate design offers increased efficiency for true maintenance-free performance and maximum power.


It's just an apples to oranges comparison where the Deka got thrown in there because it was an AGM. There will always be compromises if you put a high power battery where a high energy unit should be, or vice versus.

Condemnation should be when capacity decreases by 20%, or impedance doubles. Since nobody on here has a battery cycler that can repeatedly characterize Ah loss under constant current and constant power conditions, it's not very useful and just anecdotal.

Enter the cranking test. Assuming consistent temperatures and open circuit voltages (which equate to state of charge), this is a proxy for gauging impedance. Recall that terminal (observed) voltage is defined as:

Vt = Voc - I*R (- sign is just convention, would be + to define overpotential needed to drive current into the battery)

So let's imagine an SLI battery, of 700 CCA and 5 mOhm impedance. Load test it fully charged at half the nameplate, so:
Vt = 12.65 - 350*0.005 ; Vt=10.9V

Now double the impedance, and you're at 9.5V under load.

The lumped, generic school of thought is don't go below 10v on a load test or when cranking.

Those carbon pile testers, set to 1/2 the cca rating, to me are a bit too high of a current test. The highest rated starter I know of is the 1.7kW unit on my old Mercedes diesels. They were designed for long cranking duty of cold IDI diesels. The cars were outfit with group 49 batteries.

1.7kW = 170A at 10V conduction voltage. So why are we testing at half the nameplate cca again?

So for all intents and purposes, the don't go below 10V rule is sufficient to gauge impedance growth and thus condemnation.

For warm climates like the OP's, some liberties can likely be taken, especially if one has a jump pack and is handy like OP. Others wouldn't be as well served doing that....
 
Ohh I agree JHRZ2...

A Deka AGM is not a fair comparison to a Thin Plate Pure Lead AGM battery...

A Deka AGM is not in the same tier as say a Northstar X-2 etc...

I do think the original writer of that information was trying to let people know that a battery labeled a AGM battery does not necessarily mean it will be up to very severe long term duty... Say like a fork lift or a golf cart etc... I believe that was one of the writer's points he was making... And it was convincing. I think the Deka AGM battery did like 300 deep cycles vs the TPPL AGM batteries doing 700 to 800 to 900...
 
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