121R Battery Group Size Alternatives ?

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I am thinking of replacing the car battery on my 2009 Accent. There is really not a lot of choices available in the 121 group size.

My father in law is a retired engineer and lives in an area that has colder winters than where I live in Pennsylvania. He will not use the OEM battery spec for his cars. He selects the battery based on the tray size, clearance, etc. He says he wants the biggest battery with the most amps.

Is his method sound? Does anyone know of any alternatives to the 121R group size?
 
If you happen to still have the OEM battery in your car, I'd replace it with the OEM size and not worry about it. Look up the measurements on batteries and look at the available space you have. Maybe a 124R will fit if you have room? ? ?
 
I also am happy to find the biggest battery that fits. I think there are some legitimate reasons for it. They can put out more current, and for me, my main reason is that larger batteries typically have a longer reserve capacity. I figure if I accidentally leave a light on, it's less likely to drain and kill the battery (and consequently, more likely it will still start). I put a 24F in the place of the tiny original 51R.

With that said, there's probably no reason the OEM shouldn't work just fine.
 
With such a small 4 cylinder engine any healthy battery will crank it if it's at the oem cca. If there's no symptoms of slow starting there's no reason to out engineer them here.
 
I had a 2001 Accent and it came with this skinny battery but the tray was bigger and even had another hole drilled and tapped for a "regular" battery.

My dad had a "regular" battery for a 93 Ford escort that fit perfectly. Make sure the posts are the polarity you want as cables aren't always long enough to stretch the "wrong way".

I've found the funny sized batteries only come in "gold" and cost $130, so if one can get a "silver" battery in a bigger size for $80 they're way ahead.
 
If a bigger one fits ok then go for it. I have a group 24F in my Camry that calls for a group 35 (24F is bigger) and it fits perfect, a lot more CCA too.

Walmart has batteries for $48.88 that are made by Johnson Controls, that's what I put in my car last week.
 
I went with an Energizer (JC) 26R in my Accent. However, I had to buy a new positive battery terminal from Hyundai since the screw-crown clamp didn't fit. I don't remember the part number, but it was a direct swap.
 
I think I got taken for a ride.. But on my Subaru Legacy, I went with a different size battery than what was recommended due to height issues. New group 85 Autocraft Gold battery was maybe 30cca less than the group 35 battery they recommended, both still much better on paper than the oem subaru battery. Well, that new battery only lasted like 1 year. Went to advance auto parts to try and get a replacement, they said no go since I didn't go with what their computer recommended, they could not honor the warranty. It sounds plausible, but I don't know, I just said ok and went to walmart a half a mile down the road.

So I would see this voids any type of warranty before someone does this. No more Advance Auto Parts batteries for me because of this though.

Specs of the group 85 I went with, versus the group 35 that was recommended.

Battery Type: Lead Acid
BCI Group Size: 85
Cold Cranking Amps: 625 amps
Cranking Amps: 780 amps
Deep Cycle/Starting: Starting
Height: 8 in
Length: 9 1/16 in
Maintenance Free: Yes
Reserve Capacity: 95 min
Terminal Type: Top Terminal
Voltage: 12 v
Weight: 33 lbs
Width: 6 13/16 in

Battery Type: Lead Acid
BCI Group Size: 35
Cold Cranking Amps: 640 amps
Cranking Amps: 800 amps
Deep Cycle/Starting: Starting
Height: 8 13/16 in
Length: 9 11/16 in
Maintenance Free: Yes
Reserve Capacity: 100 min
Terminal Type: Top Terminal
Voltage: 12 v
Weight: 38 lbs
Width: 6 7/8 in
 
Originally Posted By: neilwestlawn


He says he wants the biggest battery with the most amps.

Is his method sound? Does anyone know of any alternatives to the 121R group size?


This is not unsound. A bigger battery will have more capacity, and in a slow drain present on all modern vehicles, 3+ weeks with no driving, it will stand a battery chance of having enough juice left to start the vehicle.

If one is simply impressed with high CCA numbers, Look to Odyssey AGM batteries. I have a group 27 Northstar AGM and its ability to crank my engine quickly is just scary impressive. It can also handle being deep cycled as long as it receives high initial amperage on recharge and is charged until amps taper to 0.5% of the 20 hour AH capacity at 14.46volts at 77F.

Starting batteries can fudge for super high CCA numbers with thinner more numerous more porous plates. But these thinner plates are more fragile and will be damaged more when discharged below 80%.

My personal preference, since I do intentionally deep cycle my battery then require it to start my vehicle, is to get a battery which can handle deep cycles. The AGM can be a much better' marine/ dual purposes battery, compared to flooded batteries sold as marine batteries. If I were to choose between two batteries of the same dimensions and price tag, I would get the one with lesser CCA's as it is likely more resistant in deep cycle usage.

Consider that when a modern car sits undriven for 3 weeks or so without a maintainer attached, the battery is essentially being deeply cycled.

A prompt recharge to a true 100% is best. It will take at least 7 hours of driving, for a healthy battery to return to 100% charged when it is drawn to the point it needs to be jumpstarted.

Most people assume the alternator is a magical instant battery recharger, but Lead acid batteries can reach 80% charged quickly, but that last 20% takes hours, no matter What.

There is no way to force a battery to 100% charged any faster. Voltages should not exceed 15 on a 12v battery.

People like to talk about this battery or that battery being well made and lasting X amount of time, as if the battery itself is responsible for its longevity, or lack there of.

90% of a Lead acid battery's lifespan is directly proportional to how much of its lifespan it remains as close to fully charged as possible. So brag about battery life if you must, but instead of praising any brand of battery for long life, praise instead the vehicle's voltage regulator, and one's driving habits that allow the battery to stay up near 100% charged for its whole existence.

The hotter the battery the faster its acid eats its plates too, but a hot environment is not the death knell of batteries. Hot weather increases the self discharge too, Self discharge can be 15% a month at 77F, and significantly higher than this when the battery is aged, and higher in higher temperatures.

So again the thin plate starting battery might be being deeply cycled through sitting undriven, and increased self discharge higher temps and the fact that it takes a long time to fully charge a battery, all collude to send a battery to the recyclers.

Good luck on finding a suitable battery. If you want it to last as long as possible, get a charger which can fully 100% charge it overnight, and use it monthly, even if it is a daily driver.
 
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