new battery is smaller than OEM

[snowshew]

Hello,
I am replacing the OEM battery in my 2009 Hyundai Elantra, a 121R. (13 Alaskan winters of service.) I bought a NAPA Legend on sale today "guaranteed to fit" my Elantra. The OEM battery is 8 7/8 wide, 6 1/2 deep and 8 inches tall to the top of the plastic case (8 3/4 to the top of the posts). The NAPA part number 75121R is 8 1/8 wide, 6 1/2 deep and 7 1/4 to the top of the plastic case (8 to the top of the posts). It will fit as the hold down doesn't know that it is shorter and narrower (left-right) than the OEM battery it is replacing. NAPA's website says this battery is 8.25 wide, 6.93 deep and 8.125 tall. I see different references to what a 121R should be online. Can someone tell me if I should be concerned/annoyed that this batter is quite a bit smaller that the battery my car came with? The cranking amps on the battery are correct, I just assumed that the replacements should be nearly identical to what came in the car. A misperception on my part? I browsed BCI charts and don't see a group that matches much closer, it just seems like NAPA (East Penn) is undersized for this group. Thank you-

 

[CharBaby]

I'd be more concerned with the output of the battery meaning, CCA/CA as compared to your OE battery or other brands that fit you Elantra.

 

[RAR]

I’d think that as long as the hold down clamps that new battery in place and it doesn’t move, the main concern is output given your conditions in Alaska.

If it’s ok, then I’d say it’s nothing to be worried about if the hood down is working.

 

[atikovi]

As long as the CCA are in the same ballpark, don't worry about the size.

 

[michael007]

I see on a Hyundai forum that in 2012, a 121R sized OEM battery had 600CCA.

What does the label on the new battery say?

 

[snowshew]

I'll stick this one in and not give it any more head space. It seems like it is as close to the size of the battery tray/original battery as I am going to find in an East Penn-made unit. The original had 550 CCA, as does this one. I believe it is the same in all but a few dimensions and those are reasonably close. It is labeled 121R and it would be hard to make a convincing case that it is in fact the incorrect battery.

Thank you all for the feedback!

 

[benjy]

in very cold climates bigger aka more CCA is better as cold lessens the CCA. East Penn in Reading Pa makes batteries for Napa among others BUT like Wallys batteries are likely sourced from closer makers due to their weight + shipping cost +my Wallys about 70 miles away likely gets East Penn batteries with their brand on them + thats my choice for their better price + of course less time setting after ACTIVATION is BEST!!

 

[FZ1]

I'll stick this one in and not give it any more head space. It seems like it is as close to the size of the battery tray/original battery as I am going to find in an East Penn-made unit. The original had 550 CCA, as does this one. I believe it is the same in all but a few dimensions and those are reasonably close. It is labeled 121R and it would be hard to make a convincing case that it is in fact the incorrect battery.

Thank you all for the feedback!

If not too late, I'd return it and get the biggest battery and highest CCA you can fit. WM is cheap and fresh. .02

 

[nthach]

I'd be more concerned with the output of the battery meaning, CCA/CA as compared to your OE battery or other brands that fit you Elantra.

The aftermarket will recommend smaller but equal in CCA batteries where the retailer wants to keep inventory to a minimum. The group 35 battery fitting many Japanese cars calling for a 24/27 battery is one such thing and the older 34/78 battery to fit almost all GM/Mopar products from the 1970s-2000s as well.

The smaller battery will have less reserve capacity which may or may not matter if you don’t have the hotel loads on deadhead.

 

[Snagglefoot]

I have see this in other sizes where they lump a few of the battery types into just one. Maybe this saves on producing too many sizes.My 24F was smaller than the normal size designation.

 

[Nukeman7]

Hello,
I am replacing the OEM battery in my 2009 Hyundai Elantra, a 121R. (13 Alaskan winters of service.) I bought a NAPA Legend on sale today "guaranteed to fit" my Elantra. The OEM battery is 8 7/8 wide, 6 1/2 deep and 8 inches tall to the top of the plastic case (8 3/4 to the top of the posts). The NAPA part number 75121R is 8 1/8 wide, 6 1/2 deep and 7 1/4 to the top of the plastic case (8 to the top of the posts). It will fit as the hold down doesn't know that it is shorter and narrower (left-right) than the OEM battery it is replacing. NAPA's website says this battery is 8.25 wide, 6.93 deep and 8.125 tall. I see different references to what a 121R should be online. Can someone tell me if I should be concerned/annoyed that this batter is quite a bit smaller that the battery my car came with? The cranking amps on the battery are correct, I just assumed that the replacements should be nearly identical to what came in the car. A misperception on my part? I browsed BCI charts and don't see a group that matches much closer, it just seems like NAPA (East Penn) is undersized for this group. Thank you-

I encountered the same situation in my 2010 Elantra. Although all battery catalogs list the 121R as the OEM battery, it is not the case. I found that a Group 35 battery was 100% identical to the original battery that came with the Elantra, which I purchased new off the showroom floor. I think some of the Elantras were outfitted with the 121R battery while others came from the factory with a Group 35 battery. However, I have not found any catalog listing that calls for anything other than a 121R.

 

[John105]

I'd be more concerned with the output of the battery meaning, CCA/CA as compared to your OE battery or other brands that fit you Elantra.

If the same group size I wouldn't be concerned. It's very typical, however, in the case of a 24F, to have someone recommend a group 35. Older cars would have the two as OE depending if a "cold" or "winter" package were selected. In this case, I would not want the smaller battery. I've swapped 24Fs and H6/48 and I didn't measure them. I highly doubt they were the same as what was replaced down to 1/8". Also alarming is the price increase of the 24F since pre pandemic, vs. the H6 which is the same.

 

[snowshew]

I encountered the same situation in my 2010 Elantra. Although all battery catalogs list the 121R as the OEM battery, it is not the case. I found that a Group 35 battery was 100% identical to the original battery that came with the Elantra, which I purchased new off the showroom floor. I think some of the Elantras were outfitted with the 121R battery while others came from the factory with a Group 35 battery. However, I have not found any catalog listing that calls for anything other than a 121R.

I think I saw a write up on Elantra batteries from these years (yours?) mentioning this discrepancy but it was hard not to believe the NAPA website declaring that it should be a 121R for my car, nor did I have the foresight to bring the OEM battery with me when I picked up the new one to verify that it was correct. After reading your post this morning I got motivated to bring the 121R back to NAPA and investigate. Sure enough, the Legend in Group 35 is a match, with a higher CCA and reserve capacity to boot. I brought the Hyundai one with me and put it on the counter so the salesman would understand that the computer was in fact incorrect. He swapped the batteries for me with no trouble and now the 35 is under the hood. Glad to have an exact match that was made in the US in Aug of this year. Thank you for posting!

Without reading this website and asking questions of the collective knowledge base I would have had nothing to go on, that is, no way to start finding the right battery, nor even knowing that it exists. Thanks to all who offer advice on such a wide range of topics, it is a huge help.

 

[Nukeman7]

Really glad that it worked out for you snowshew. I suspect that Hyundai failed to provide the complete battery fitment information to the major battery manufacturers including East Penn, Clarios and Exide. I checked the Advance Auto, Autozone, NAPA, WalMart, O'Reilly's and Interstate Battery fitment guides and all of them indicated the 121R was the only correct battery for that generation of the Elantra. I did the legwork by measuring the dimensions of the OEM battery and cross-referencing it to the BCI Group 35 unit.

 

[Carmudgeon]

Unfortunately, application guides aren't 100% correct, and can contain errors and omissions, or fail to note if a particular application can support more than one size.

And when discrepancies are encountered in the field, how likely do you think anything other than head scratching occurs? If there's no error reporting system, or it isn't utilized, the status quo is maintained.