Car Tech 101: What you need to know about car batteries (On Cars)

Summary

This video script offers an in-depth look at car batteries, focusing on the importance of understanding group numbers, which indicate size, terminal location, and polarity. It discusses the significance of cranking amps and cold cranking amps, highlighting the impact of temperature on battery performance. The script also explores different battery types, including lead-acid, AGM, and deep-cycle batteries, each with unique characteristics and uses. Additionally, it provides practical advice on preserving battery life through mechanical disconnect switches or battery tenders, ensuring viewers are well-equipped to make informed decisions when purchasing and maintaining car batteries.

Takeaways

• 🔋 The group number of a car battery is crucial as it indicates the dimensions and terminal positions, with BCI numbers being a standard reference.
• 🔌 Understanding battery polarity is essential because car cables are fixed and cannot be adjusted to reach the opposite polarity.
• 🏎️ The power of a battery is measured in amps, with cranking amps and cold cranking amps indicating performance at different temperatures.
• ❄️ Cold cranking amps are a key metric for battery performance in harsh winter conditions, showing how well a battery performs in freezing temperatures.
• 💰 Higher cranking amps generally mean better performance but also a higher cost for the battery.
• 🔬 Lead-acid batteries are common in cars, composed of lead sheets suspended in a sulfuric acid solution.
• 🚗 AGM (Absorbed Glass Mat) batteries offer benefits like no leakage, quick recharging, and resistance to vibration, but are more sensitive to overcharging.
• 🔁 Deep-cycle batteries are designed for applications requiring sustained power output and are more resilient to repeated draining and recharging cycles.
• 🚫 To prevent battery discharge in cars that are not frequently used, consider using a mechanical disconnect switch or a battery tender.
• 🛠️ Replacing a car battery is a straightforward task that can be done as a DIY project, offering a satisfying repair experience.

Q & A

What is the significance of the group number in car batteries?

The group number in car batteries signifies the physical dimensions (width, length, and height) of the battery case, the location of the terminals (top or side), and the polarity of the battery. It is a standardized system devised by the Battery Council International (BCI).

Why is the group number counterintuitive in terms of battery size?

The group number can be counterintuitive because a smaller group number does not necessarily mean a smaller physical size. For example, a group 24 battery is physically larger than a group 75 battery, even though the number 24 is smaller.

What is the importance of polarity in car battery selection?

Polarity is crucial in car battery selection because it determines where the positive and negative terminals are located. Car cables are of fixed lengths and cannot be stretched to accommodate different terminal positions, so the battery's polarity must match the car's setup.

How are the power capabilities of car batteries measured?

The power capabilities of car batteries are measured in amps, specifically through cranking amps and cold cranking amps. Cranking amps are tested at 32° F, while cold cranking amps are tested at 0° Fahrenheit to simulate harsh winter conditions.

What is the difference between cranking amps and cold cranking amps?

Cranking amps measure the battery's power output at a relatively cool temperature (32° F), while cold cranking amps measure it at a much colder temperature (0° Fahrenheit). The latter is a better indicator of a battery's performance in harsh winter conditions.

What type of battery is commonly used in cars, and how does it work?

The most common type of battery used in cars is the lead-acid battery. It consists of lead sheets suspended in a bath of water and sulfuric acid. When the circuit is closed, a chemical reaction between the lead and acid generates electrical current.

What is an AGM battery, and what are its advantages over a traditional lead-acid battery?

An AGM (Absorbed Glass Mat) battery is a variant of the lead-acid battery where the electrolyte is absorbed into fiberglass sheets. Its advantages include no leakage, quick recharging, resistance to vibration, and a longer life. However, they are more expensive and sensitive to overcharging.

What is a deep-cycle battery, and how does it differ from a car battery?

A deep-cycle battery provides a lower number of amps but can deliver power for a longer time and recover better from being drained. It is typically used in applications like RVs and boats, where sustained power is needed rather than for starting engines.

Why might a car battery become depleted if the car is not driven often?

A car battery can become depleted if the car is not driven often due to parasitic or phantom loads that continue to draw power even when the car is not in use. This can lead to a discharged battery that won't recharge.

What is a simple mechanical disconnect switch, and how can it help preserve a car battery?

A simple mechanical disconnect switch allows you to physically disconnect the negative cable from the battery, preventing it from discharging due to phantom loads. This can be a simple and effective way to preserve battery life when the car is not frequently used.

What is a battery tender or battery minder, and how does it help maintain a car battery?

A battery tender or battery minder is a trickle charger with monitoring capabilities. It keeps the battery topped up by providing a gradual charge when the battery level gets low, helping to maintain the battery's health and preventing discharge.

Outlines

00:00

🔋 Understanding Car Batteries

This paragraph delves into the intricacies of car batteries, emphasizing the importance of the group number, which is a crucial identifier for battery dimensions and terminal locations. It clarifies that group numbers, also known as BCI numbers, are standardized by the Battery Council International. The discussion then shifts to battery power, measured in amps, with a distinction made between cranking amps and cold cranking amps, highlighting how performance varies with temperature. The summary concludes with an overview of battery construction, contrasting traditional lead-acid batteries with AGM (absorbed glass mat) batteries, noting their differences in leak resistance, recharging speed, vibration resistance, and sensitivity to overcharging.

05:00

🔌 Car Battery Maintenance Tips

The second paragraph focuses on strategies for preserving battery life when a car is not frequently used. It suggests using a mechanical disconnect switch to prevent phantom drain by physically disconnecting the battery. Alternatively, it recommends using a battery tender or minder, which is an intelligent trickle charger that monitors and maintains the battery's charge. The paragraph addresses safety concerns about keeping such devices connected, suggesting the use of a mechanical disconnect as a precaution. The video script ends with a teaser for an upcoming 'how-to' guide on installing car batteries and directs viewers to the website for more car tech information.

Keywords

💡Group Number

The 'Group Number' refers to a standardized code used to identify the physical dimensions, including width, length, height, and terminal location of a car battery. It is crucial for ensuring that a battery will fit in a specific vehicle and that the battery terminals align with the car's electrical system. In the script, the presenter explains that group numbers are counterintuitive, as a smaller number does not necessarily mean a smaller physical size, and they are devised by the Battery Council International (BCI).

💡Terminals

Terminals are the points on a battery where electrical connections are made. They can be located on the top or side of the battery and are critical for connecting the battery to the car's electrical system. The script mentions that the group number also indicates the polarity and location of the terminals, which is essential because car cables are of fixed lengths and cannot be adjusted to fit different terminal positions.

💡Polarity

Polarity in the context of batteries refers to the positive and negative charges of the battery terminals. Correct polarity is vital for the proper functioning of a car's electrical system. The script emphasizes that polarity must be considered when selecting a battery, as incorrect polarity can lead to issues with the car's starting system.

💡Cranking Amps

Cranking Amps (CA) is a measure of the amount of electrical current a battery can deliver at 32° F for 30 seconds and is a key indicator of a battery's ability to start an engine. The script explains that cranking amps are tested under 'cool but not cold' conditions, providing a measure of the battery's performance under less severe weather conditions.

💡Cold Cranking Amps

Cold Cranking Amps (CCA) is another measure of a battery's ability to deliver current, but it is tested at 0° Fahrenheit to simulate harsh winter conditions. The script points out that CCA is a more accurate representation of a battery's performance in cold weather, and a higher CCA rating indicates a better battery for cold climates.

💡Lead Acid Battery

A 'Lead Acid Battery' is a type of rechargeable battery in which lead plates suspended in an acid bath react chemically to produce an electric current. The script describes this as the conventional black square battery, where the reaction between lead sheets and sulfuric acid generates the electrical power needed to start a car.

💡AGM Battery

An 'Absorbed Glass Mat' (AGM) battery is a variation of the lead acid battery where the electrolyte is absorbed into a glass mat, preventing leakage and allowing for better resistance to vibration. The script highlights the benefits of AGM batteries, such as quick recharging, longer life in frequent start-stop conditions, and their suitability for off-road and performance vehicles.

💡Deep Cycle Battery

A 'Deep Cycle Battery' is designed to provide a lower current over a longer period and can recover from being deeply discharged multiple times. Unlike starting batteries, deep cycle batteries are more suitable for applications that require sustained power output, such as in RVs and boats. The script contrasts deep cycle batteries with car batteries, emphasizing their different use cases.

💡Phantom Drain

Phantom Drain refers to the small but continuous electrical current that can drain a car battery when the vehicle is not in use. The script suggests using a mechanical disconnect switch to prevent phantom drain by physically disconnecting the battery when the car is not in use.

💡Battery Tender

A 'Battery Tender' is a device that provides a controlled, low-level charge to a battery to keep it in good condition when not in regular use. The script discusses using a battery tender as a method to preserve battery life, especially for cars that are not driven frequently, by maintaining a proper charge level without overcharging.

Highlights

Introduction to the importance of understanding car batteries beyond just their function as a power source.

Explanation of the group number and its significance in battery dimensions and terminal locations.

Misunderstanding about group numbers and physical size, with an example of a smaller group 75 battery.

Importance of polarity indicated by group numbers and its impact on car battery cables.

Historical context of group numbers and the role of Battery Council International (BCI).

Discussion on battery power measurement in amps and the difference between cranking amps and cold cranking amps.

Practical implications of battery performance in cold temperatures and its effect on cranking amps.

Cost correlation with battery amps and the balance between performance and expense.

Introduction to lead acid batteries and their construction with lead sheets suspended in sulfuric acid.

Explanation of AGM (Absorbed Glass Mat) batteries, their construction, and benefits over traditional lead acid batteries.

Advantages of AGM batteries in terms of leak resistance, quick recharging, and vibration resistance.

Drawbacks of AGM batteries, including higher cost and sensitivity to overcharging.

Introduction to deep-cycle batteries, their lower amps, and suitability for prolonged power output rather than starting.

Practical advice on preventing battery discharge in cars that are not frequently driven.

Recommendation of using a mechanical disconnect switch to prevent phantom drain in cars.

Introduction to battery tenders or minders as a method for maintaining battery charge.

Addressing concerns about fire hazards and the use of battery tenders with mechanical disconnects.

Teaser for an upcoming how-to guide on installing car batteries and its ease as a DIY repair.

Transcripts

[Music]

now when I say batteries and cars these

days I could easily mean a giant battery

that runs a car but not in this case

we're going mainstream the battery that

we all deal with this big nasty heavy

big old black lead box that you never

think about until it dies and then you

think about it laced with obscenities so

when you have to go buy one you need to

understand a little bit about its

parameters now the first thing you're

going to have to learn about or

encounter in batteries is something

called the group number it's the first

thing they ask you at the parts counter

a group number tells you a lot of things

this is a group 24 battery here this is

a group 75 it's actually physically

smaller so that's a little

counterintuitive what the group number

tells you is a combination of width

length and height of the physical

battery case it also tells you where the

terminals are located this is a top

terminal battery this is a side terminal

battery places where you attach the

cables are on the side the other thing

group number includes in it is the

polarity this is positive this is

negative but they could be opposite in a

different group number and that's very

important because a car's cables that go

to the battery are a fixed length and

you can't just stretch them to move

around positive is only going to reach

to the positive so the polarity the

posts have to be in the right place for

each cable now by the way group numbers

were devised by something called the

battery Council International it's a

trade group for battery makers as a

result you might also see the group

number referred to as the BCI number

like we see on this one same

thing now now the next thing you need to

know is the power of the battery to put

it in common parlament and that's

usually expressed in amps that's what

really matters because the voltage is

the same these are all 12volt batteries

unless you have a very old car that uses

a 6volt battery but we're talking

vintage rides probably pre mid 660s at

the most recent so 12volt battery but

how many amps does it have which tells

you how much oomph it has to turn over

your engine now you find that measured

in two main ways cranking amps and cold

cranking amps cranking amps are tested

in the lab at 32° F that's considered

cool but not cold cold cranking amps are

tested in the lab at 0° Fahrenheit which

more simulates really harsh winter

weather and there's a big difference

batteries perform much less stoutly in

very cold temperatures and as a result

when you look at the cranking amp versus

cold cranking amp number on a battery

it's going to be quite different the

more cranking amps the better within

reason it won't hurt your starter your

starter will only draw as many amp amps

as it can use in a given situation then

again more amps equals more

cost okay our last consideration is

construction and chemistry inside the

battery now your conventional black

Square battery like this is probably

what's called a lead acid battery it's

got sheets of lead suspended in it that

are in a bath of acid it's water and

sulfuric acid and those two combine when

the circuit is closed between the plates

inside creates electrical current that's

about as far as my chemistry goes by the

way a battery is actually six batteries

inside here are six separate cells each

one puts out two volts or so that gets

you 12 V now a variant on the lead acid

battery is an AGM or absorbed glass

matte battery it takes that fluid that

solution and absorbs it into typically

some fiberglass sheets and beds those

down next to the plates that create the

electricity and those can be flat or as

you can tell from this battery they can

also be wound up in coils and held back

way again still six assemblies 2 volts

each 12 volts total benefits to an AGM

battery is they can't leak because

there's not anything slashing inside

they tend to be very good about

recharging quickly they're very good

about resisting vibration for cars that

are off-road or performance cars that's

very important and they tend to have a

longer life when they're called upon to

start a car very frequently on the

downside they tend to be substantially

more expensive and they're very

sensitive to overcharging if there's

anything wrong with your charging system

or an external charger you attach to

them now another variant of battery

you'll see that is typically not used in

cars but you'll see it sold right

alongside these is what's called a deep

cycle battery a deep cycle battery will

give you a lower number of amps so less

current but it can put out power for a

longer time and it can bounce back from

being drained much better many times

these are used not so much for starting

but deep Cycles are used for running

things so think RVs in boats as opposed

to car engine starts

[Music]

now frequently you're shopping for a

battery because it was in a car that

didn't get started or driven very often

and the thing got depleted and wouldn't

charge up again sound familiar well when

you shop for a new battery for that car

consider a couple of things one is to

get one of these simple mechanical

disconnect switches by turning a knob

you actually physically disconnect the

negative cable on the battery that means

it almost is impossible for it to

discharge through Phantom drain while

sitting there connected into a car that

may not get driven very often another

way to accomplish this idea of battery

preservation is not to disconnect it but

to actually connect it all the time to

what's called a battery tender or a

battery minder this is basically a

trickle charger with a little bit of

intelligence in it that will monitor the

battery's condition and when it gets a

little bit low it'll give it a gradual

charge to keep it topped up now some

folks have fear about fire hazard about

keeping one of these connected all the

time and that's where your very simple

mechanical disconnect is going to be

some nice peace of mind okay there's a

quick primer on the outline of knowing

understanding and buying batteries we're

going to do a how-to soon and tells you

how to put one of these things in it is

the easiest most satisfying repair you

can do on your car look for that soon

more cartech demystified right now at

ceton cars.com click on cartech

[Music]

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