bad battery or not (arguing with Sears)

[theksmith]

today i wasted my breath arguing with Sears over what constitutes a bad battery. to sum it up, i believe that the reserve capacity of a AGM battery and it's CCA are two independent properties of the battery, and though loosely related, the battery may test "ok" for CCA but still no longer be able to deliver a good portion of the rated reserve. can someone with more firm knowledge of battery chemistry weigh in on this?

to me, my die-hard platinum battery clearly has an issue as it will only charge to 12.30 volts and no longer can sustain a typical load for even half as long as was common for the first couple years of it's life. this has happened fairly suddenly over the past couple months. i have a second battery, exactly the same, but 1 year newer... it still rests at 12.80+ volts and can sustain a decent load.

however, Sears has no way to do a run-down test to determine the reserve capacity or amp-hour rating. so at 12.30 volts and 90% of the rated CCA, they say the battery is fine. they would not even consider a pro-rated credit for it, even though it's still under the full 4 year replacement warranty.

 

[ldivinag]

i'm in the same boat.

i had my truck sit for about a year when the timing belt blew (and being unemployed...).

anyways, prior to that the diehard platinum worked like a charm. prior to that the optima batt i just replaced another optima batt did not last 6 months before it was dying on me.

anyways, got my truck going and tried to have sears look at the batt. i had or was able to get the batt to at least charge up and start the truck for about a couple weeks.

now it would not last overnight. i kept a jumper box so i could start the truck in the morning.

anyways, twice i went to sears and they took the batt out, put on their "charger" and i waited about 30- 60 minutes.

the kept saying battery is fine... blah, blah, blah. but still even when charged with their charger it would last a few days before overnight would "kill" it and me needing my jumper box.

i finally said screw it and bought an AGM from autozone for $150. so far, two weeks into and no issues.

the DH PLAT maybe great but then again sitting for a year...

 

[mathers420]

I've had similar problems with a die hard platinum.

I never killed mine and charged it regularly with an 8 amp charger that has an AGM specific setting.

My battery is now sitting at 12.43 volts. As soon as you put any load on it, it drops to 8 volts and then slowly rises back to around 10 volts. Remove the load and it is back at 12.43 volts. When load testing, it shows ~ 100 cranking amps.

I haven't taken it back yet because I live 3 hours away from the closest sears auto center (they aren't in Canada anymore)

 

[DaveInDenver]

Open circuit voltage is an indicator of battery condition, the easiest to measure.

After a full charge cycle an AGM should sit unloaded (a volt meter does not present any appreciable load) at 12.8V. If it does not then you are below 100% state of charge (SOC) regardless of remaining current capacity. If the battery has sufficient voltage then you would measure capacity to more fully determine condition. Even left in circuit with most stuff off, like your starting battery with the key off, a good battery shouldn't be much below 12.8V anyway.

They don't even need to run a full charge profile, just an hour sitting on a battery conditioner should bring it above 50% SOC, which for an AGM 12.3V open circuit indicates that state of discharge. If after a charge an AGM battery sitting at anything other than 12.8V is clearly failed/failing IMHO.

 

[DaveInDenver]

BTW, if Sears disagrees that a battery can drop below 100% voltage fully charged they may be right, but that also requires a more comprehensive test than just a basic charger and volt meter. You need to measure power and time to determine condition, especially for reserve capacity.

At minimum you need a real load to judge CCA, although you can simulate it to some extent with your headlights and what-not. A good battery, even a deep cycle, should be able to handle a decent load for a short time without dropping much. The low beams in your headlights will draw about 55W each, so both will draw 110W or about 8A to 9A from a good battery, which will power this without dipping much initially (this mimics a ham radio, which all batteries should have no trouble with).

You might be able to get the current pretty high with high beams, fog lights, etc. A winch might also be a good demonstration load. In any case, to fully measure it you'd want to see it achieve 1/2 the rated CCA for 15 seconds. So a 900CCA battery would need to supply 450A for 15 seconds regardless of measured voltage. A bad battery's voltage will dip pretty low and fail this, but it's current & time that are key.

To measure reserve will take longer. Starting from a fully charged battery you measure how long it takes to hit 10.5V flowing a constant 25A. If Sears says a 12.3V starting point is fine then they need to measure this. If the battery says it has reserve capacity of 120 minutes, then they need to show you that it is 10.5V after 120 minutes in this test. Again, it's current and time that are key.

 

[theksmith]

Dave, your posts exactly highlights my 2 beefs with them...

- when i asked what an acceptable open voltage after them charging it themselves was, they said somewhere around 11.8v - to me that is ridiculously low for any type of vehicle battery. so my 12.3v is considered "good" to them.

- second, they have no way to do a draw-down test and instead make the judgement about the condition of the battery based solely on the open voltage and a cranking amps type test. i would not have bought an expensive AGM hybrid style battery in the large group 65 form factor if i wanted just a starting battery, IMO it needs to deliver a fairly high percentage of the rated amp-hours to be still considered "good".

i have not done a measured draw-down test, just a seat of the pants thing. i know that i used to be able to run my fridge (with nothing else on) for over a day and still crank the vehicle easily (even in warm weather) - now the battery is to the point it won't even turn over the vehicle after full day of running the fridge even in cold weather.

i'm going to a different Sears tomorrow to see if i have better luck.

 

[jrose609]

Good luck. I had the same issue with my PM1. I have to charge my battery each night to start my rig, but Sears says its fine. Said to replace my starter and alternator and that would fix my problem.

 

[DaveInDenver]

Unless they are willing to do current and time testing, they have no choice IMVHO to accept the initial voltage criteria. It's up to them to explain any justification otherwise, you are on absolutely firm ground from a chemistry standpoint.

There is no universe where 11.8V is acceptable. For all lead acid types an open terminal voltage of 11.8V~11.9V would indicate a completely discharged battery. Such a low voltage would indicate the discharge is so deep that you are approaching the point of risking reversing one cell.

They might reasonably argue that a fully charged settling voltage of 12.65V, 12.7V might be OK. You'd ideally want 12.8V or maybe a bit higher. But there's no reason to argue over a couple of percent error, which could be in the meter, temperature, etc.

Does the warranty say anything about technical criteria?

 

[4xdog]

I'd go to a different Sears store if you can. Might not be better, but you already know what you have at the one you visited.

 

[coax]

Good info, I love battery/electrical threads. I am by no means an expert, but one thing you could try as well is after having sears charge it, let the battery sit for an hour, see if the surface charge dissipates quickly and drops the Open Circuit voltage down. That's kind of a wasted hour though if they still won't warranty, and I'm not sure if a surface charge would disipate much over an hour, even if the battery is on the way out? Or put a small load on the battery for a minute?

Also I believe AGM's have a slightly higher voltage that standard lead acid batteries, so while a DHP put on a charger and then measured might "pass" a standard battery test, my guess is once it was charged, let rest for 24 hrs, and the measured the voltage comparted to what an AGM should be, it could be "bad"

 

[dwh]

to sum it up, i believe that the reserve capacity of a AGM battery and it's CCA are two independent properties of the battery

That is true of any lead-acid battery - not just AGM type.

If you have a battery that is for example 100 amp hours capacity, and it becomes 90% sulfated, then it might act like a perfectly good battery...but it'll only be a 10ah battery, not a 100ah battery.

It will still charge up to a proper "full charge" voltage. It will still drop down to a proper resting voltage after it sits a while.

It may even be able to supply the full rated cranking amps.

But under load it'll be dead in 1/10 the time it lasted when new.

 

[phatman]

Sears Diehard are easy to kill

I too had a problem with my Sears Diehard Platinum. I Had a PM1 in my Tacoma for two years. Right after I moved I went on a trip with a lot of banging around. Then for 6 months after the trip I would drive the truck weekly to keep everything fresh. I thought the battery would be fine being that I drove it regularly on the freeway. Well it sat for about 1 month and when I went to start the truck, nothing. dead... would not even crank.

Well I jumped it and ran the truck on the freeway to charge it up. I then got my charger Batteryminder 12248 (which BTW was at the time rated for Odyssey batteries) and tried to recondition the battery per the instructions. I found that the charger would go into float mode right away. It would then reset it settings. I look in the manual and found that it's a sign that the battery that is discharging (internal short.)

I decided to clean my battery even thought I had little hope of this helping, and while cleaning it I found two cracks in the case. These cracks ran between the terminal post of both terminals of like polarity. Well that was it for me. This is supposed to be a sealed battery.

I took it to a Kmart with a Sears auto center. I told them it was out of a Boat that had been on a battery maintainer and when I did my maintenance check I found the cracks. I also said that I can not have a battery that could potentially be bad as this is used on an Ocean vessel. Done, they replaced it with a battery that was built 3/2012 (a year old.) When I got home I put it on the same charger and put in 2 amps overnight. Clearly the battery maintenance at Sears is lacking. All is good so far but it's only been one night.

The thing about these batteries is that they are not built to the same quality that an Odyssey branded one would be. For example, the case is all plastic instead of metal jacketed. I feel these batteries are not really up to being under the hood of a off-road truck. The heat and bouncing can't be good. I also feel that the battery does not handle deep discharge as well as they advertise.

In any case, I have a new battery and some theories. First I plan to put it in the bed of the truck with a proper battery box. The box will give it some structure and the location will keep it cooler, and not have as much shock as under the hood does. secondly I plan on keeping the battery on the charging/ maintainer during long periods of inactivity. Also I plan to research a bit more research because they is conflicting information on how to properly charge these batteries (lead vs AGM setting.)

 

[dwh]

Also I plan to research a bit more research because they is conflicting information on how to properly charge these batteries (lead vs AGM setting.)

Odyssey tech manual has the recommended charging profile (Page 15):

http://www.odysseybattery.com/documents/US-ODY-TM-001_0411_000.pdf


Bulk to 14.7v,
Absorb at 14.7v until current flow drops below 0.001 of C10 amps (for example: 100ah (battery capacity or C) x 10 (C)10)) = 1000a x .001 = 1a)
Or, absorb at 14.7v for 6-8 hours
then drop to
Float at 13.6v


In other words, basically the same charge profile as any other lead-acid battery except it likes to get up to 14.7v on the bulk and keep it there during the absorb, instead of bulking up to 14.4v and dropping to 14.2v for absorb the way most chargers do (and most manufacturers recommend).

A 3-stage 14.4v/14.2v/13.6v charger will still get the job done - but it'll take longer (prolly an extra day or two of sitting at float voltage) to creep up those last couple of percentage points to reach 100% full.

 

[highdesertranger]

this thread s why i no longer go to sears for batteries. highdesertranger

 

[keezer37]

I said from the get go when this whole "rebadged Odyssey" thing started some years ago and folks were to understand that the only difference was the name; when a corporation as large as Sears contracts with a supplier, they can do more than just change the name of the battery. It's just speculation on my part but the Platinum batteries are heavily discounted from their assumed Odyssey counterpart for a reason... as indicated here.