New Battery --> Group 25 (stock), 24 or 34???

gathermewool

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Having had success with the LOW, LOW, LOW stock CCA in my '14 FXT I'm not concerned about it as a main feature for my new battery. I have the below specs for NAPA The Legend batteries of each group whittled down to my priority, in which case group 24 wins:

BTW, I'm taking the advice of some on here to upgrade my battery before it gives me problems. I showed weak on the latest load test. I'm also installing a new starter and think it's a good idea to replace the battery to give it its best lift, too.

[Linked Image]
 
I agree to go with the group 24....

I have a group 24f in my car.. I'm guessing the length is good in your case has well.
 
Typically Marine batteries have ~20% lower CCA than starting batteries, indicating slightly thicker and thus more durable plates.

They usually also have less warranty, but defects aside, the battery properly recharged is not going to fail within warranty period anyway.

I believe its wise to stuff the largest marine battery that one can, in their vehicle, even if a dedicated starting battery is lighter and has higher CCA and appears to be a better bang for the buck.

I know marine batteries come in size group 24, but they also come in group 27 which is about 12 inches long and group 29/31 which are 13 inches long 6.75 wide and 9.25 tall to the tops of the automotive posts.

Marine batteries usually come with regular clamps AND threaded studs for wingnuts or regular nuts. Marine/dual purpose batteries will often say 'deep cycle' on them, but their plate thickness is not really comparable to that of a true deep cycle battery.

A true deep cycle 12v flooded battery other than 8d or 4d sizes which are huge and 120 and 150Lbs each respectively, would have pathetically low CCA, and the few true deep cycle 12v batteries that do exist, do not even list CCA figures, only amp hour capacity figures at 20, 10 5 and 1 hour rates. They are a GC12 size group and the trojan t1275 is likely the best example, although interstate dealers can order them. They used to be made for interstate by USbattery, but that has likely changed and I am told by those who called and asked that one GC12 is nearly as expensive as a pair of GC-2's which are 6 volt golf cart batteries and the most durable deep cycle flooded battery option. A pair of GC-2's wired in series for 12v is likely about 650 CCA, and together weigh no less than 128Lbs. This gives a good idea what starting batteries sacrifice in order to eek out as many CCA as they do for a fraction of the weight of a true deep cycle battery.
Here's a '12v marine battery guts compared to a GC-2's guts:
[Linked Image from marinehowto.com]


If this topic is of interest to you, please read the following link, where I stole that pic from:

https://marinehowto.com/what-is-a-deep-cycle-battery/


The trojan t-1275 is almost 11.5inches tall and a slightly bigger footprint than a group 31, about 85 Lbs, and would likely have about 500CCA. where a group 31 starting battery likely has 1000CCA and weight about 55 to 60 and a marine 31 has 650 to 700CCA and weighs ~64Lbs.

https://www.trojanbattery.com/product/t-1275/

Marine batteries are likely best cycled no deeper than 80% state of charge whereas true deep cycle say 50%. Starter batteries should ideally never be discharged to 80% much less any percentage below that. 12v Marine batteries in deep cycle service almost always require higher voltages held significantly longer than expected, to revert the specific gravity to its maximum. If they are regularly deep cycled without this extended recharge regimen, they degrade quickly, but if never deep cycled or cycled deeper than 80% can give very good service as a starting battery.

As always the deeper the lead acid battery is discharged, and the more often it is discharged, the more important the recharge regimen becomes.



I'm going to be modifying a battery tray in an older Toyota Tundra to stuff a Marine 27 or 31 into the stock location soon. The owner plans to drive it to Costa Rica once the pandemic passes, and the itty bitty ancient battery currently in there is loose, with the most disgusting terminations I have seen, but without corrosion, and it still starts 'just fine'.

5 years ago I began modifications to fit a t-1275 inside my engine compartment, but stopped when a single group 27AGM located under the body proved more than capable of taking care of my needs, and I could stuff two under there. Now there is no battery in my engine compartment, or battery tray for that matter.

I think my owner's manual specs a group 34 battery with no less than 550CCA, and I have used 24, 27's and a 31 in the stock location, but the 31 was a shoehorn fit. and the handle design was the only reason it could be fit, as one handle could be pivoted out of the way and allow the hood to close all the way, but it was resting on the edge of the battery.

Good luck and do look for a marine group 24. Wally world likely has them, and they are likely less than half the price, and half the quality of Trojan's group 24, which is likely the best group 24 wet/flooded marine battery available.

but if you dont have the desire or ability to insure regular true full charges via plug in charging sources or solar, don't bother getting highest possible quality batteries, as they are not immune to living their life chronically undercharged, and will only slightly outlast the cheaper option when chronically undercharged. but if properly recharged to full regularly, they will likely outlive it by double, at the minimum.

As always, the best lead acid battery chronically undercharged, will not outlive the worst lead acid battery kept fully charged or at least returned to very high states of charge often and promptly after any significant discharge.
 
I'll inquire today about the Trojan battery.

I utilize a DC bench PS to charge my starter batteries every 1-3 weeks at 14.4VDC overnight. Charge current usually drops to
We rarely leave any load on while the car is off. My wife has a bad habit of using the powered tailgate, but that's about it. If the kids get fussy while one of us is out of the vehicle to, say, run an errand, the other will play music through our phone's speakers instead of turning to car the ACC, to prevent wasting juice.
 
If your battery, when you hook it to your bench top power supply set at 14.4v in the evening , quickly tapers to 1 amp, and then you leave it overnight at 14.4v, it was already at a high state of charge, you are likely overcharging the battery leaving it on teh battery for 10+ more hours at 14.4v.

This does more than use more water from electrolysis or 'boiling' as so many like to call it, but causes positive plate degradation too.

You should really get a hydrometer, temperature compensated, like the OTC 4619 and dip the cells and STOP applying 14.4v once the specific gravity has stopped rising, or has reached its expected maximum.

If one or two cells do not respond to 14.4v but remain lower than expected, then bringing the battery to as high as 16.2v might bring them higher while overcharging the other cells. This is called equilization and it is abusive to the battery, and should only be performed when one or more cells reads 0.015 lower than other cells as measure by the hydrometer.

Arguably, starter batteries with their thinner plates are even more susceptible to damage from overcharging than their marine and deep cycle brethern and EQ charging even more detrimental to the cells which might not require such treatment.

The Group 24 trojan has a good Data sheet, and likely quite a high price to match.

https://www.trojanbattery.com/product/24tmx/

And while it says deep cycle in bold letters, on other Trojan data sheets, one will see that their 12v marine batteries are almost rated at half the total rated cycles, as their real deep cycle lead acid flooded or AGM or Gel batteries.

Good luck. This is my Last battery/battery charging related post on Bitog.
 
@WRCSIXEIGHT, thanks for the great response. I'm still learning everyday, so I appreciate posts like yours!!!

After replacing the starter, the over-run noise was gone and the starter sounded 10X better; however, it also sounded a little bit slow to start and, after a couple of repeated tests, it began to click before finally starting - the battery was dying after 6.5 years, 78k miles, and several drain-to-dead events (OEM Battery). I put it on the charger for a couple of hours @14.4VDC while waiting for the battery to be delivered to my local NAPA and charge current almost immediately went down to
With so many people online complaining about how bad the OEM subary batteries are, I feel like my charging scheme was THE main reason it lasted so long, even after a few episodes where it was drained to the point where the car wouldn't start (and then charged to full soon after). While I don't yet use a hydrometer, I do pay careful attention to the batteries in other ways.

//

Most of the time, our automotive (and Power Wheels, but that's another story lol) batteries are as fully charged as any other vehicle on the road, based on my frequent charging. Even still, maybe three quarters of the time, depending on how the stars align (recent driving/charging patterns), the batteries will take PS-limited maximum current (~5.2A) prior to reaching 14.4VDC using the VOLTAGE potentiometer. In these cases, I typically slowly raise voltage to 14.4VDC so as not to exceed around ~ 4.5A to prevent unnecessary wear on the PS. This usually only takes about a minute or so, considering the batteries are usually reading 12.7+ volts to begin with.

I usually keep a very close eye on the batteries while charging, and was wrong to post so generally and cavalierly about simply hooking up 14.4VDC and walking away for up to 24 hrs. I don't do or recommend that at all! I only charge while I'm home (for obvious reasons) and check up on the battery(s) every hour or so while charging. Once the charge current has dropped to nil I terminate the charge immediately. This is generally < 0.1A @ 14.4VDC and typically 0.06-9A, depending on vehicle (i.e., my FXT has a larger parasitic draw than the Legacy). I try not to let the charge dwell at 14.4VDC with the battery saturated for any extended period of time.

In the few years that I've been doing this, I may have had to add water only once. I say, "may", because I can't recall whether I added water before beginning my charging scheme or after (I believe it was before). I have not seen any appreciable consumption since (all flooded cells with accessible caps or see-through case).

I also used to perform a short equalizing charge @15.0VDC for maybe an hour or so, but have since given up that practice.

I have in the recent past left a battery @14.4VDC overnight and HAVE sometimes seen nil amps prior to disconnecting in the morning. I plan to stop this practice and only charge during the waking hours. Like I said, I haven't noticed any water consumption, but there are safety and wear concerns that supersede the convenience of an overnight charge.

Finally, I think I'll start relying on my CTEK 3300 to maintain my wife's battery, since she can go several days at a time without driving, even before the pandemic. In a recent test, I actually found that JUST after the CTEK completed its charge, current settled at ~0.3A (300mA) when I hooked up 14.4VDC to it. That's WAY better than my BatteryTender; I don't remember the exact current upon termination, because I never caught it in time, but it was an order of magnitude higher, IIRC.
 
Originally Posted by gathermewool
That's WAY better than my BatteryTender; I don't remember the exact current upon termination, because I never caught it in time, but it was an order of magnitude higher, IIRC.



Correction: NOT an order of magnitude. More like 100% higher. Sorry for the confusion.
 
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