Car batteries are the heart of a vehicle’s electrical system, providing the essential power needed to start the engine and run electrical components. The world of car batteries has evolved significantly, offering various options tailored to different needs. This article explores the different types of car batteries, their pros and cons, their historical evolution, and special considerations for our classic cars.

While the majority of car owners will tell you that the power in their car comes from the engine, I’d be inclined to somewhat disagree. Certainly, it’s the engine that propels the car forward (or backwards), but if it wasn’t for the electric power provided by the battery, the engine would just be a big lump of metal. Considering the battery forms such a critical part of the car, isn’t it time we take a further look into the development history, different types, and which would be best suitable (and why) for our cars, helping you make an informed choice when it comes to buying your next battery.

THE HISTORY & EVOLUTION OF BATTERIES
If you thought that the development of the car was an interesting journey of the last 100 years (which it is, let’s be honest about that), you’d be even more amazed by the journey of the batteries that power it all. Did you know that electric vehicles (EVs) were hugely popular before the introduction of internal combustion engines? Let’s go back to the early days to where it all started, the first lead-acid battery, before making our way through the 19th and 20th centuries towards the cutting-edge lithium-ion cells of today.

Early Beginnings
Our journey begins in Paris 165 years ago, where we meet the brilliant Gaston Planté (1). Born in 1834, Gaston’s passion for science led him to pursue a higher education in physics and chemistry. His journey took him to the ‘Conservatoire National des Arts et Métiers’, where he worked as an assistant lecturer in physics in 1859. Despite ongoing developments in electricity storage, it was Gaston’s groundbreaking invention of the first lead-acid rechargeable battery (2) that revolutionised the field. His design consisted of two lead plates submerged in a sulphuric acid solution, and when a voltage was applied, a chemical reaction would occur that stored energy in the form of lead dioxide on the positive plate and sponge lead on the negative plate. This simple design laid the groundwork for future developments in battery technology, and once his fellow scientist Camille Alphonse Faure introduced a more practical and efficient method for manufacturing batteries in 1881, mass production and commercialisation became possible. Soon after, the lead-acid battery found applications in telegraphy, lighting, and the automotive industry. Did you know it would be another 3 years until 1884 before Karl Benz introduced the first true automobile (3) using a 4-stroke engine and that batteries formed a key element in his design?

The First Electric Vehicles
Contrary to common belief, electric vehicles (4) were quite popular in the late 1800s and early 1900s before the introduction of combustion engines. Yet despite their popularity, these early EVs struggled with the same issues as their modern cousins: a limited range and performance due to the heavy weight and low energy density of the batteries.

The Internal Combustion Engine
With the continued improvements of the combustion engine, it soon became apparent that this would form a more suitable powerplant for vehicles and as a result, the demand for EVs soon began to decline. However, as these engines couldn’t work without a reliable power source, the development and improvement of batteries continue. Although it wouldn’t be for another 50 years before the next major breakthrough is made.

Mid-20th Century
It was highly likely that the next round of battery developments was a direct result of the war effort. By now, batteries were used in everything, from cars and tanks to planes and radio communications. It became obvious that a replacement of the lead-acid battery was needed, something which would be maintenance-free and far less prone to spillage and leakage. Introducing the sealed lead-acid battery. Yes, I know, it’s still a lead-acid battery, but this one is sealed! Anyway, they soon became the new standard and saw usage in a wide range of applications, including uninterruptible power systems (UPS), backup power for telecommunications, and, of course, automotive use. Combining this development with advances in plate technology, including the use of different alloys and paste formulations, a steady improvement in the durability and performance of these lead-acid batteries was realised. To top it off, batteries lived longer than ever before as new electrolyte solutions were tested and applied.

Late 20th Century And Modern Day
With the world relying more and more on electricity and electric power sources, battery development switched into a higher gear, resulting in rapid advancements in the field of power storage. The first major milestone was the introduction of the ‘Absorbent Glass Mat (AGM)’ and gel cell batteries in the mid-’80s. AGM batteries use a glass mat such as fibreglass to absorb the electrolyte, making them spill-proof and more resistant to vibrations, along with better cold-start performance and less maintenance requirements. Gel cell batteries, on the other hand, use a gelified electrolyte, providing even better resistance to vibration and temperature extremes, making them suitable for the harshest of conditions and deep-cycle applications. At the same time, ‘Enhanced Flooded Batteries (EFB)’ emerged as an improvement over the traditional flooded lead-acid design, providing better durability and charge acceptance, laying the foundation for the start-stop technology, which has become a standard feature on almost all cars.

Meanwhile, a completely new type of battery also entered the scene: the lithium-ion battery. First developed in the 70s and 80s, it wasn’t until the 90s that commercial production revolutionised the automotive industry. It had taken almost 100 years, yet the time had come for EVs to make a comeback. And once significant advancements in their management systems came along, this new type of battery with its higher energy density, longer lifespan, and reduction in weight, quickly became the new power source for all hybrid and electric vehicles. Heavily backed by government lobbying, EVs have become the latest trend, to the point that even classic cars are now undergoing a destructive heart transplant in order to become part of it.

AVAILABLE TYPES OF CAR BATTERIES
Nowadays, an extensive range of different types of car batteries is available to us, and they all offer their pros and cons. Let’s take a look at the options we have and why they may (or may not) be a suitable candidate for your car.

Lead-Acid Batteries
As you may have gathered from the extensive history lesson on batteries, the lead-acid type (5) has long been the cornerstone of providing cars with the required power source to keep them going. And for good reason, as they are reliable and affordable, making them a popular choice for most conventional vehicles. However, it’s not all positive news; They require regular maintenance in the form of checking the electrolyte levels and topping up with distilled water to prevent them from drying out. On top of that, they are prone to spillage and corrosion, which can cause further damage to the battery terminals and surrounding areas if not properly managed.

That being said, you’d probably struggle to find these types of batteries in your local store. A quick search at popular car shops shows that all flooded lead-acid batteries come in the form of the sealed type, thus removing the maintenance and spillage elements from the drawbacks. And other than their heavy weight, now leaves us with very few negatives. No wonder that this tried-and-tested technology continues to power a significant percentage of vehicles on the road today, most likely including yours as well.

On average, these batteries cost less than £100.-

Absorbent Glass Mat Batteries
In contrast to the standard lead-acid battery, AGMs (6) represent a significant advancement in lead-acid technology. As mentioned, they use a glass mat to absorb the electrolyte, making them wholly spill-proof and much more vibration-resistant. Combining this with the lack of maintenance requirements and excellent cold-start performance, it makes them a far better option for those of us living in colder climates or needing that extra bit of performance and reliability.

The downsides of these batteries are their reduced capacity over time, their sensitivity to overcharging, and their significantly higher cost, which could be a consideration for the budget-focused consumer. However, with the amount of money we tend to spend on our cars (especially the E9 with its rust issues), we will most likely not be budget-focused.

On average, these batteries cost over £200.-

Enhanced Flooded Batteries
EFBs (7) form the middle ground between traditional flooded batteries and the more advanced AGM types. They are maintenance-free and provide a better result compared to standard lead-acid types when it comes to performance, vibration resistance, and longevity. They also cost less than AGM batteries, which makes it a happy medium and a suitable option for may car owners. Did you know they are the go-to battery for vehicles with a start-stop technology thanks to their durability and charge acceptance at a reasonable cost?

On average, these batteries cost between £100.- and £150.-

Gel Cell Batteries
Being another type of lead-acid battery (I told you the technology remains the cornerstone of car batteries), they use a gelified electrolyte (8), making them spill proof and more importantly, highly resistant to vibrations and extreme temperatures. Their robustness makes them the perfect choice for owners who use their vehicles infrequently or store them for longer periods, as these batteries have a very low self-discharge rate and can maintain their charge for extended durations without degradation.

The major downside to these batteries is the high cost (especially compared to the traditional car battery) and the fact they are less efficient in high-current applications, although the latter shouldn’t affect us too much, thankfully.

On average, these batteries cost between £100.- and £200.-

Lithium-Ion Batteries
Representing the cutting edge of battery technology (9), they offer numerous advantages over the traditional lead-acid design. First of all, they are significantly lighter, which can contribute to better weight distribution, fuel efficiency, and an improved handling and performance. They also have a much longer lifespan and can be recharged far quicker, which makes them the only considerable option if you’re looking to convert your classic to an EV – please don’t. Lastly, they are a potential choice for those building race cars, as their high energy density allows more power to be stored in a smaller and lighter package (see LiFePO4 batteries next).

The downside to all this is their cost, as they are far more expensive than any lead-acid option, and they require a sophisticated battery management system to monitor and control the charging and discharging processes, ensuring safety and preventing issues like overheating and overcharging. However, for most, the performance benefits outweigh the cost and often justify the investment.

Lithium Iron Phosphate (LiFePO4) Batteries
Lithium Iron Phosphate (LiFePO4) batteries (10) are a type of lithium-ion battery that are known for their stability, safety, and longevity compared to other lithium-ion batteries. Developed in the late 1990s, LiFePO4 batteries have gained popularity in various applications, most importantly in the form of performance car batteries. Compared to standard lithium-ion batteries, this type uses different chemicals which pose a lower risk of thermal runaways and fires, making them a suitable option for automotive use. At the same time, they have an average lifespan of up to 4,000 charging cycles, far outdoing any other type of battery available on the market. Combine this with their low weight (sometimes only 10% of a standard lead-acid battery) and you have found the perfect solution for those building a race car. To top it off, they have a significantly lower environmental impact compared to some of the other options.

The major downside to these top-of-the-range batteries, and possibly the only one, is their initial investment cost, which can easily set you back well over a £1,000, although the extended lifespan can potentially offset and justify this over time. You will also need a suitable charger, which will likely cost you another £100-£200 depending on the amp size required.

CONSIDERATIONS
Fantastic! Now that we know what options are available to us, we’re one step closer to deciding which one to buy next time our battery dies. However, depending on your style of ownership, you’re still left with quite a few options (theoretically).

Authenticity
I suspect a large majority of the readership are of the type who would like to keep everything factory original, or at least maintain its appearance. This means that a traditional flooded lead-acid battery will most likely be your preferred option, as they are period-correct and maintain the vehicle’s authenticity. However, be aware they also lack in performance and reliability when compared to the other options available, but at least they offer you a maintenance-free solution compared to the original batteries our cars came with.

If you’re open to it, you might want to consider AGM batteries, as they offer better performance in comparison and still look like an authentic battery from the outside.

Only The Best For Me
If you’re more like myself and you’re looking for the best option, irrespective of cost, the gel cell batteries are the way to go for road cars. Their improved performance, lifespan, resistance to vibration and extreme temperatures, and maintenance simplicity make them the ultimate battery to power our cars. It can even cope with anything else you decide to build into your car, being it a modern stereo system of high intensity rally headlights. Granted, they cost a lot more than the standard battery, but the pros far outweigh this little set back. Besides, in the grand scheme of costs, it still is a small investment.

Sacrilege Conversions
Although certainly not my cup of tea, I am aware that some of us are considering joining the EV trend with their classic cars by changing the characteristic straight-six M30 with a non-saying Tesla electric engine and a box of batteries to power the lot. In that case, using lithium-ion batteries is your best (and only) option.

Race Cars
Those with the need for speed are probably looking for a lightweight option that is highly resistant of vibrations and provides the ultimate in battery performance. The only sensible option would be a LiFePo4 battery as they are a straight-forward swap and due to their smaller size and weight, can be placed almost anywhere in the car, thus further helping with better weight distribution. Just make sure to check the FIA and/or governing body regulations to ensure you’re allowed to use them.

CHARGERS
In theory the alternator should charge your battery while driving. That’s all good and well, until you realise that our cars are most likely standing still for the majority of the year. This means that the batteries aren’t frequently charged and as such will cause them to slowly deplete and possibly get damaged over a long period of time. To prevent this from happening, you could disconnect the battery since our cars don’t have any intricate systems that require constant power. However, this won’t stop the battery from draining naturally.

Instead, it is highly recommended to invest in a quality trickle-charger and conditioner. One of those brands is CTEK (12) from Sweden, which specialises in the production of chargers for different types of batteries, including standard lead-acid, AGM, and lithium. Their latest model, called “CS One”, is so advanced it only requires a single press of a button, and its clever algorithm will check the type of battery connected and what program it needs. Plus, it has the added benefit of reversible clamps. Another recommended brand is NOCO (13), who not only offer fantastic chargers, but they also make a jump starter device called “Boost”, which isn’t much bigger than a pint glass, and can easily start an E9.

Both brands offer different capacities depending on your needs and budget, alongside a wide range of accessories, including battery connectors that you can install permanently. You can even go as far as having an external connector available to charge the car while fully closed and locked.

CONCLUSION
It is essential that we understand the differences between batteries and why they may be suitable for our car, contineously balancing performance, reliability, and authenticity. Though traditional lead-acid batteries remain a viable option, modern replacements such as the AGM and gel cell types can provide all of these, especially when the car is standing still more than it is driven. Something that sadly applies to too many E9s.