Honda Group 24 Battery 31500-SF1-A1100M

Oct 20, 2005
Scruffy City
So, the Acura uses a Group 24 battery. Not the much easier to find 24F (the terminal polarity is opposite.)

This was among the cheapest with the longest warranty battery I could find in stock.



Heres where it gets sketchy:


Nice give me a new battery with half a charge.


Many hours later.


You have removable caps.

Take a specific gravity reading with the above hydrometer on all 6 cells.
Make sure no bubbles are sticking to the float.

Are they all 1.265 or higher and within 0.010 of each other?

Let the charger go through another cycle.. recheck specific gravity. did it improve?

New batteries, and especially those which have sat on a shelf and self discharged for a few, to several months, can behave outside expectations when first put into service, but far more noticeably if that service is deep cycle duty as opposed to the relatively easy task of starting a fuel injected engine in summertime.

I would not put any weight into whatever electrical gizmo decides to declare, until the battery has seen some level of discharge to 80% or less and been promptly and hopefully fully recharged, or nearly so, and allowed to cool off to ambient in the 77f range or below.

turn on the headlights for a half hour and immediately put on the 'smart' charger at 6+ amps over night and dip the cells the next AM.

If one were trying to make a battery live as long as it truly could, knowing the the true maximum specific gravity when new is wise, so on subsequent recharges, one can judge just how well their charger is doing.

Often one will find that their 'smart' charger needs to be restarted over and over to attain that previously established maximum temperature compensated specific gravity.

It will vary among different batteries and often, among the same cells of the same battery, if one bothers to actually take and record the data.

But of course batteries are only rented, and such efforts, even on an anal retentive site like Bitog, that stresses PPM of boron and moly in their 5w-30, are often dismissed as a waste of time.

A 'new' battery that has sat and self discharged for months will often need a deeper cycle and extended recharge cycle, perhaps to higher than usually recommended voltages, for specific gravity to max out, and without such care, will lose performance and capacity faster than it otherwise would.

The temperature compensating Hydrometer is the flooded battery polygraph. it will show when a battery is truly fully charged, but it will not reveal the remaining capacity, as compared to when new, healthy, and fully charged.

New, but shelf aged Lead acid batteries can often give excellent service, but the chances of excellent longevity increase substantially when the specific gravity maximum has been achieved/established early on it its usage.
Most never bother until the battery is on its last legs anyway and will not benefit from such care.

But ignorance is indeed blissful, and one can hope for failure within the warranty period.
Production date on that battery is 10/19 - “J9RFK” J=October, 9=2019. That should explain the low charge on the battery.

24 group size isn’t too uncommon but I believe you are correct on the longest warranty battery being it’s 100 months warranty. 36 month free replacement and 64 month prorated.
I suspected it might be pretty old, I believe this battery only goes up until about 2000 in Honda’s and don’t imagine there is a ton of dealer traffic on a car that old. If it had been a 24F I could have gotten one easily for about 60% of this one. Most 24 batteries were 160 +.

2019 coincides roughly with when this dealer opened though I think it was prior to October.

I appreciate the advice on the hydrometer, I don’t know that I’ll go to that level but I have restarted the charger several times and will run it another cycle at the first opportunity.
UNless you intentionally discharge the battery a fair amount, The charger will likely spend very little time at higher absorption voltages, and drop to the 13.2v float voltage for the rest of the time you leave it plugged in.

If one uses the AGM setting, float is usually 13.6v.

This higher float voltage applied overnight might help to dissolve some sulfate from sitting on a shelf for so long.

I found achieving maximum specific gravity with a smart charger, to be a time wasting effort, and a lesson in near futility, but my batteries get cycled deeper, and getting that last 1% into them really helps them live and perform well for a respectable amount of time.
next time get the Everstart Extreme 24 marine starting battery at Walamart. 1000 MCAs, $80 and 45lbs about the heaviest you can get in the 24 size. probably last much longer than the honda battery will.
Having a battery with a J9 date code on the shelf shows that that dealer's battery vendor (Interstate handles Hondas batteries IIRC) sucks. Twice a year we get stock rotation from Deka (interstate does the same) and anything over 12 months gets rotated back for fresh stock. That battery should have never been sold. If we have a battery on the shelf that is getting old but hasnt been rotated yet we will hold it back for rotation and order in another fresher battery.
Anybody know if 34M can replace 24?

24 > Duracell AGM Deep Cycle Marine and RV Battery, Group Size 34M?​

So the battery in the OP died.

You have to take the whole car in. This was sort of a pain, but the process was mostly painless, they replaced it.

The not painless part is they broke to terminal cover and grilled the clamps. - This is why i hate other people working on my cars.

We will see if they do the right thing.
So to bring this to a close:

This is a Hendrick dealership.

They twisted up the clamps on the cables by over tightening them and twisting the square head past the built in holder. (I think they used an impact)
They broke the red plastic terminal cover.

I had texted them the same day with a photograph and asked what they would do about it and never got a reply...

Over the holidays I had the thing we don't talk about and basically couldn't do anything so I sent a letter and photos.

They sent me a new cable and reimbursed me for the cover and bolts i had bought from the local dealer here. The Negative cable is NLA and they tried to locate one but could not so i'm kinda stuck with that. Fortunately it is not too severe.

They apologized and sent me the reimbursement and cable without any arm twisting past the pictures and letter. They did seem a little miffed i went straight to the dealer principal and didn't give the lowers a chance to straighten it out but i said i felt like i did that when it texted back to their text, and that was the end of that line of discussion.

All and all i always say the measure of a dealer is how they deal with an issue, and i would say this was a solid A for service recovery.