There’s more to a car battery than meets the eye.
At first glance, between different car batteries, it’s just their color, label and size that differ.
Looks can be deceiving though…
It’s a battery’s internals that make the difference.
These are the ones we recommend depending on your requirements:
Different Car Battery Technologies
STD (standard)
Also called “wet” or “flooded” batteries. They are very common lead-acid batteries and most affordable.
They consist of lead/antimony plates suspended in liquid acid.
Calcium
A calcium battery is basically a modified lead-acid battery. These batteries can be lead-calcium, lead-calcium-silver or calcium-calcium alloy.
They are usually sealed and maintenance-free.
The antimony in the plates is replaced by calcium, often combined with silver.
The calcium component gives a lead-acid battery some advantages like improved resistance to corrosion, reduced gassing, less water usage and lower self-discharge.
Silver makes the plates more resilient to high temperatures.
Calcium batteries require a higher charge voltage (14,6-14,8V) than conventional batteries (13,8V) to get the maximum life out of the battery.
Select AGM-mode on your battery charger if your calcium battery needs to be topped-up or trickle-charged. (check manual first)
If your vehicle’s charging system isn’t optimized for calcium batteries, this may result in a far shorter battery lifespan.
EFB (Enhanced Flooded Battery)
Developed around 2008, these improved flooded lead-acid batteries have similar qualities to AGM batteries. They charge rapidly between starts and are about twice as durable as standard ‘wet’ batteries.
Some European car makers use these as a more cost-effective alternative to an AGM and they’re a great upgrade over a calcium battery.
They perform best for cars with simple automatic start-stop systems, cars without a start-stop system but with demanding driving requirements (e.g. in urban traffic) or for cars without start-stop but with extensive equipment.
The primary benefits of EFB technology are improved charge acceptance and greater cyclic durability when operating in a reduced state of charge (typical of Stop/Start applications).
As a general rule, EFB batteries can provide twice the number of charging cycles in comparison with conventional (STD) starter batteries.
Though they are widely accepted and rapidly growing in popularity in Europe and Asia, quality EFB batteries are hard to come by in the US.
AGM (Absorbent Glass Mat)
Though more expensive than EFB batteries, Absorbed Glass Mat batteries are the most popular car batteries in the US.
Their strong fiberglass layers in between the battery plates seal their boxes shut, reducing the chances of air pockets forming. This prevents irreversible damage to a car battery.
An AGM battery also offers better cold-cranking behavior because it is constructed to handle freezing temperatures better. Your car will start reliably even in the dead of winter.
SpiralCell AGM
A spiral cell battery is an AGM type battery with a spiral layout instead of plates.
Contrary to traditional lead plates, these tightly rolled lead mats can’t deform under temperature or strain. That’s why the plates can be made thinner, making it a lighter construction.
This patented design has the advantage of packing more sq. ft. of lead mats in the same volume, resulting in an even more performant design.
They are also up to 15x more vibration-resistant than classic lead-acid car batteries.
Gel-Cell
This more expensive type of battery handles extreme heat better than other battery types and has the longest lifespan (when properly charged).
That’s about the only upside.
They don’t perform well in freezing temperatures and they tend to lose power faster than AGM batteries.
Gel batteries also need to be charged at low current rates or they will get damaged.
Most car alternators charge at high current rates, shortening the lifespan of this type of battery dramatically.
Also, gel batteries don’t offer the same power and charge capabilities that other types of batteries provide.
Because of this, depending on your type of car, gel batteries don’t always meet performance standards.
Except for very specific uses, stay away!
According to sales statistics, AGM batteries outsell gel batteries 100 to 1. That says it all I guess…
Lithium
Whatever some battery brands may promise, lithium batteries (in any form or shape) are not suited as a replacement car starting battery (yet).
For a daily driver, that is…
They are awesome weightsavers for a trickle charger-fed trailer queen, featherweight race car or dune buggy though.
The main issue for use in a daily driver is that their temperature tolerance is very limited: they don’t perform well in cold nor hot temperatures.
Also, at startup in freezing temperatures, your alternator will automatically try to charge the car battery. Charging in these conditions will damage a lithium battery. (That’s why Tesla’s main lithium battery is automatically preheated before charging in cold conditions.)
In extreme heat lithium batteries can explode or catch fire too…
They have to be recharged with a lithium battery charger or they will get damaged or even catch fire (yes, again…).
Keep in mind that most, if not all, on-board automotive charging systems are designed for lead-acid batteries. Lithium batteries need a completely different charging regime.
This too can be a recipe for disaster…
How about this deal-breaker: While a full battery drain (e.g. when you’ve left your lights on) may lead to some capacity loss for any lead-acid car battery, it is fatal and irreversible for a lithium battery.
Yes, they are lighter, but did we mention that they cost up to 3x more than lead-acid batteries?
Hate to burst that bubble, but at this stage in the evolution of lithium battery technology it’s a no-no as a replacement daily driver starting battery.
As a lightweight gadget for your race car or trailer queen they’re damn hot though… in a good way that is 😉
Different Alloys
Different alloys are experimented with for lead-acid car battery plates to get an optimal balance between power, stamina, durability and price.
It’s always a compromise, these four criteria influence one another.
Past decades, large improvements have been achieved in general car battery performance and their weight/power ratio.
Modern improved “wet” lead-acid car batteries for example, often called “calcium batteries”, contain calcium and sometimes silver.
So do many other types of batteries.
The result of this improvement is manifested in increased battery life and maintaining a high starting power over time.
It has to be noted that high content “calcium” car batteries are very picky concerning charging voltage.
If not charged correctly, their life expectancy will suffer.
It’s a pain though that most battery brands don’t bother to specify exactly what type of alloys they’re using for their batteries.
Antimony? Silver? Calcium? Which ratio? Purity of lead?
Exact technical specifications like optimal charging voltage are very hard or often impossible to come by.
More often than not you’ll have to assume or guess what is actually in that sealed plastic container, based solely on the marketing terminology they throw at you.
Which Battery Size?
Size-wise the new battery must of course match the old one it will replace although sometimes a larger size with a larger capacity would fit too.
The only way to be sure is to measure the available space in the battery tray or compartment and compare it to the new battery’s dimensions.
Make sure you measure the old battery correctly for comparison, check your car’s manual or read what’s on the old battery’s label.
A car battery label should mention the battery group number. This is usually part of the battery type number, which is brand-specific.
E.g: “ODP-AGM35” or “35-675/ELT-AGM35” or “8020-164 35” all refer to “Group 35”. Sometimes “Group 35” is simply written on the label.
The physical dimensions of Group 35 batteries are approximately (LxWxH) 9 1/16 x 6 7/8 x 8 7/8 inches (9.0625 x 6.875 x 8.875 inches, 23.0 x 17.5 x 22.5 cm). (See chart below)
Most Common Sizes of Car Batteries:
Group Size | LxWxH (inches) | LxWxH (cm) |
Group 24 Batteries | 10.25 x 6.8125 x 8.875 | 26 x 17.3 x 22.5 |
Group 27 Batteries | 12.0625 x 6.8125 x 8.875 | 30.6 x 17.3 x 22.5 |
Group 31 Batteries | 13 x 6.8125 x 9.4375 | 33 x 17.3 x 24 |
Group 34 Batteries | 10.25 x 6.8125 x 7.875 | 26 x 17.3 x 20 |
Group 35 Batteries | 9.0625 x 6.875 x 8.875 | 23 x 17.5 x 22.5 |
Group 51 and 51R Batt. | 9.374 x 5.0625 x 8.8125 | 23.8 x 12.9 x 22.3 |
Group 65 Batteries | 12.0625 x 7.5 x 7.5625 | 30.6 x 19 x 19.2 |
Group 78 Batteries | 10.25 x 7.0625 x 7.6875 | 26 x 17.9 x 19.6 |
What Is CCA Or Cold Cranking Amps?
CCA or Cold Cranking Amps is the major international benchmark for the amount of power which a battery can produce for a period of 30 seconds at (0°F/-18°C), while still maintaining terminal voltage equal to or higher than 2.1V per cell.
Never mind if you’ll ever use your car in such extreme temperatures. That’s not what this is about.
It’s just the easiest and most reliable value to compare car batteries across different brands because it is measured in the same way around the globe.
What Is a Starting Battery?
Starting batteries are designed to deliver short, high-current bursts to crank an engine. They frequently discharge only a small part of their capacity (max 2%-5%).
Although these specialized batteries usually outperform deep-cycle batteries when it comes to CCA, they will get damaged when they are discharged past 20% of their capacity.
A starting battery is purpose-built to sprint the 100 yards, so to speak, not to run a marathon.
When To Use a Starting Battery?
Starting batteries are ideal for most daily drivers.
They provide a powerful starting burst and are recharged by the alternator while driving.
They are also your best choice for classic cars or any vehicle with low electric or electronic power demands.
What Is a Deep Cycle Battery?
Although deep cycle batteries look like any other car battery to people who aren’t familiar with them, in reality they’re quite different in design internally.
These batteries have a different internal architecture to provide sustained power over a long period of time and run reliably until they are 80% discharged or more before they have to be recharged.
Even though deep cycle batteries can occasionally be discharged up to 80% and beyond, this is not recommended as a frequent practice. Discharging below 45% will inevitably shorten the life of even this type of battery.
Figuratively speaking, contrary to starting batteries, these batteries truly are designed to run a marathon…
This does come with a downside however: they are not the CCA champs.
Just like a marathon runner isn’t specialized in short explosive sprints, this type of battery isn’t the sprint champion of the battery world either.
Although it has ample starting power, if you’re focused on maximum CCA, this is not the battery for you.
When To Use a Deep Cycle Battery?
Deep cycle batteries provide sustained energy, making them ideal for modern cars with lots of electronics, ATV’s with winches and lightbars etc., UTV’s, Campers,… In fact, any vehicle that is at risk of an energy deficit.
“Energy deficit” means that when you switch on all the electrics and electronic devices that are frequently used together, your vehicle is consuming more electricity than your alternator can provide. This will of course drain your car battery.
In this situation, a deep cycle battery will be able to provide much more power reserve without negative consequences on the battery’s longevity.
What Is a Dual Purpose Battery?
A dual purpose battery is ideal for applications that require both strong cranking power as well as extended auxiliary power for electrical and electronic accessories.
For this class of battery, specially designed AGM or SpiralCell AGM sealed batteries are most suited.
A dual purpose battery combines the best of both worlds…
I guess that’s about all the information you need to choose the battery that fits your needs.
These are the car batteries we highly recommend:
Best Overall Car Battery
Odyssey Extreme batteries deliver the massive starting power, rapid recovery and amazing deep cycling capability that modern vehicles demand.
They have been designed to keep up with the changes.
These batteries are built for everyday vehicles, classic and antique cars, high performance cars, 4×4 and Off-Road as well as modified vehicles.
Their plates are made of pure virgin lead (99% pure) and Odyssey packs more plates in as well.
More plates mean more surface area, and much more power.
Odyssey claims that it outperforms spiral-wound batteries of equal size.
Compared to conventional batteries, the Odyssey Extreme battery series packs twice the overall power and can triple longevity.
It can even withstand up to 400 cycles at 80% depth of discharge.
They also have the highest recharge efficiency of any sealed lead-acid battery on the market, capable of 100 percentage recharge in 4 – 6 hours.
The “Extreme” battery’s sealed design with self-regulating relief valve results in gasses being recycled internally and also eliminates acid spills.
It has high conductivity, corrosion-resistant tin-plated brass terminals and a high integrity terminal seal.
Tough flame retardant cell containers and robust internal cell connections prevent vibration damage.
With an average 3-10 years of service life and Limited 3 and 4 year full replacement – not pro rata, Odyssey batteries save consumers time, money, and aggravation too.
PROS:
- Suited for any type of vehicle
- Massive starting power
- Up to triple longevity
- Rapid recovery and amazing deep cycling capability
- Capable of 100 percentage recharge in 4 – 6 hours
- Internal design prevents vibration damage
- Limited 3 and 4 year full replacement – not pro rata
- 99% pure lead plates with more surface area
- Self-regulating relief valve results in gasses being recycled internally and also eliminates acid spills
CONS:
- Premium price (but worth every penny)
Best Budget Car Battery
AC Delco’s Gold Automotive AGM Batteries have high cycling capabilities.
They are also ideal for “start/stop” vehicle applications.
The AGM design is 100% leak and spill proof because the electrolyte is permanently held in the glass mat separator instead of free flowing within each cell.
Due to a maintained pressure on the low resistance silver-calcium stamped alloy plates, the amount of active mass lost from the grid significantly reduces, resulting in longer life expectancy.
This design is very charge-receptive, reduces water loss and reassures maintenance-free performance.
In traditional vehicle applications, AC Delco Gold Automotive AGM Batteries also have a 36-month free replacement period and a 7-year warranty.
Made in Germany
PROS:
- AGM silver-calcium low resistance design
- Durable and vibration-resistant
- Maintenance-free
- Increased charge-receptiveness and power output
- 36-month free replacement period and 7 year warranty
- Made in Germany
CONS:
- Silver-calcium battery: needs high charging voltage (14.4V-14.8V) for longevity (check your car’s manual or test its alternator)
Best Starting Battery
These high-performance SpiralCell AGM batteries are the ultimate in starting power. They are designed to deliver a strong ignition boost for a reliable start-up every time.
The Optima RedTop range has high power delivery and extreme resistance to the most common causes of battery failure.
Thanks to their SpiralCell technology with high purity lead sheets (99.99% pure) they last up to three times longer and are fifteen times more vibration-resistant.
They recharge faster, their casing is virtually spill-proof and can be mounted in any position.
PROS:
- Ultimate starting power
- Lasts up to 3x longer
- Up to 15x more vibration-resistant
- Ideal for low-tech cars that aren’t loaded with electronic accessories
- Lightweight
- Small, compact design
- Tough polypropylene casing
- Pure lead plates (99.99% pure)
- SpiralCell AGM construction
CONS:
- Unconventional looks
- Not optimized for cars with lots of demanding electronics, ATV’s with winches and lightbars etc., UTV’s, Campers,…
Best Dual Purpose Car Battery
These high performance AGM batteries are one of the very few car batteries on the market that are truly dual-use.
Due to their SpiralCell construction they combine premium starting power with impressive cycling capabilities.
These heavy-duty batteries are perfect for today’s vehicles that are packed with accessories.
Low internal resistance because of the use of pure lead plates (99.99% pure) means more consistent power output and faster recharge times.
This results in up to three times longer service life and up to fifteen times more vibration resistance.
They are leak-proof, mountable in virtually any position, maintenance-free, and can handle more than 300 discharge / recharge cycles.
They even work well for Heavy-Duty tractors or forklifts, that’s how tough they are…
PROS:
- Truly dual-use: premium starting power + impressive cycling capabilities
- Ideal for vehicles that are packed with electronic accessories
- Lasts up to 3x longer
- Up to 15x more vibration-resistant
- Lightweight
- Small, compact design
- Tough polypropylene casing
- Pure lead plates (99.99% pure)
- SpiralCell AGM construction
CONS:
- Unconventional looks
At under 15 pounds, this is one of the most popular lightweight AGM batteries.
It is able to start larger engines easily for racing and offers daily driving capability for 4 & 6 cylinder motors with ease.
With 1067 Pulse Cranking Amps this has enough power to start more than any other battery in its weight class.
The 21 pounds version even cranks V8 engines.
Even though you could also use them to spark your daily, we think they’re ideal for lightweight sports cars, weekend racers and trickle-charged trailer queens.
Go ahead, add some lightness…
PROS:
- Ideal for lightweight sports cars, weekend racers and trickle-charged trailer queens
- Light: Less than half the weight of your average standard battery
- Versatile: For 4, 6 (15lbs) and 8 cylinder engines (21lbs)
- Reliable: AGM capabilities
- Powerful:
Pulse Cranking Amps: 1,380 (21lbs) / 1,067 (15lbs)
Cranking Amps: 742 (21lbs) / 574 (15lbs)
Cold Cranking Amps: 550 (21lbs) / 425 (15lbs) - Also suited for daily drivers
CONS:
- The use of a trickle-charger is advised
- Battery compartment looks empty
Final Thoughts
Don’t randomly pick a car battery just based on price, looks or brand reputation.
There’s much more to it than meets the eye.
Choose the wrong battery and you’ll pay much more in the long run because of lower longevity and reliability issues.
Each car needs a specific type and size of battery, depending on its design, use and electronic accessories.
Here’s our thoughts in a nutshell:
If you own a low-tech, classic or older car with hardly any electronic gadgets, consider an Optima RedTop as a replacement battery.
It’s a powerful and robust cranker.
If you drive the latest generation of high-tech wheels and want to feed all that high-tech stuff without running out, go for the Optima YellowTop or Odyssey Extreme. Same goes for ATV’s or UTV’s with power-demanding accessories and light bars.
No worries, they can cope.
For lightweight sports cars, weekend racers and trickle-charged trailer queens we think the Braille Lightweight Racing Battery is a great weight-saver.
Wanna save a couple of bucks for a burger and beer?
We think the AC Delco Gold AGM Battery is your best pick.
Choose wisely and you’ll be cranckin’ your engine effortlessly for years to come…
Hope we got you started 😉
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