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Mark’s Tips: How to Choose the Right Car Battery

Marks Tips

It’s Monday morning and you’ve just woken up, showered, and brewed that cup of strong coffee to balance out your slight hangover. But things really couldn’t be better; you’ve slept off the Sunday Scaries and today is one of those days where you’re geared up and ready for a cruise to the office before you crush the day – even though your manager has recently called you back into the building from Monday thru Friday because of low Covid cases, things could be far worse.

You step into your 2015 F-150 and turn the key (or push the button, if you’re fancy) to start your engine, but hear nothing. A quick check of the ears are made to be sure it’s not just you, and as you try again, all you see is your dash lights fade to darkness – or perhaps you hear it crank once or twice followed by the fast “click-click-click-click” of the starter solenoid struggling to stay engaged. That sparkly but slightly coffee-stained grin gets wiped right off your face. A DEAD BATTERY. This might be one of the most defeating “why me?” moments for someone to wake up to, if not most defeating in general.

Fortunately, there are steps you can take that may prevent you from immediately calling the tow truck, or perhaps even revive your battery enough to get you to work and replace it yourself, all while potentially saving hundreds. Read on…

Car battery

Car batteries – can I just buy the cheapest one that fits?

No! Not always, that is. Unless you’re lucky and your car only needs a battery with a low CCA (Cold-Cranking Amperage) rating that happens to be the right size. Another varying factory will be the terminal orientation for the replacement battery, because a battery that looks good otherwise but has reversed positive and negative terminals won’t work, and could actually cause damage to some vehicles.

Most auto parts stores and dealer parts departments will have a large number of batteries currently in stock on any given day. They can also help you look up the correct type of battery for your exact model, according to what their system reads. This includes CCA rating, size, and terminal locations.

The easiest way to know what type of new car battery to get would be to observe the readings on your old battery. There are labels that indicate “group size” and “minimum CCA rating”, and are found typically on the top or side placard on the battery.

  • “Group size” indicates the dimensions and also the terminal type of the battery. Examples of group sizes would be: 41, 42, 48, 24, 24F, 51, 58R, and 65.
  • “Cold-Cranking Amperage or CCA” indicates the minimum amount of cold cranking amps your starter requires when starting the engine. Lighter-duty cars will require less amperage. CCAs will typically be in the range of 350 to 600, with heavier-duty trucks requiring more than 600 CCA.
Store Battery

If you’re in doubt that your old battery wasn’t the correct one installed on your vehicle, or maybe the old one was a temporary replacement installed by a towing service, then a commonplace to turn would be at an auto parts store – the parts people behind the counter should have the right specifications for the correct replacement battery. Also, some stores have a “research yourself” electronic or paperback kiosk in the aisle, that aids in looking up the right battery for your model. Another place to look would be in your owner’s manual.

How car batteries work

Batteries are devices that convert chemical energy into electrical energy and flow from positive (+) to negative (-). The standard lead-acid car battery is made up of six cells, each cell supplying around two volts. The total voltage obtained from these cells combined is more than 12 volts from a fully charged battery.

Most cars use only one battery that powers the starter motor and the various engine and chassis-related electrical functions. Other cars that require more voltage or amperage to components will be supplemented with another battery, usually called a “deep-cycle” battery. These batteries will usually be more rugged and can withstand more abuse from the elements without being depleted as quickly as the standard lead-acid type.

Cut battery

When a typical battery is charged and the engine is off, it should display about 12.6 volts with a multimeter. When running, the alternator is then charging the battery and it should read in the range of 13.5 to 14.5 volts. If the voltage is below 10.6 volts, your battery is running low on juice. There are three things that can be done from here:

  • Charge the battery with an automotive charger before attempting to start the car again (the lower the charge rate, the healthier it is for the battery)
  • Jump start the car with jumper cables or a battery booster (now widely available as a small lithium-Ion pack, slightly larger than your smartphone) and run the engine for a while to let the alternator charge up the battery. If you’re driving a stick shift car, there’s always a chance of stalling the engine so make sure you’re not in a dangerous spot if this happens. If the car battery is not accepting a charge, it may not restart!
  • Replace the battery outright
  • Load test the battery (simulate starting) with a load tester to see if the battery will even accept a charge (battery disconnected from car)

Often times if the car has been sitting for a while, the battery just needs to be recharged back to a healthy state. If you do end up replacing the battery, be sure to take the old one back to the auto parts store - many stores offer cash or store credit incentives for old batteries to be recycled.

Starting and running your car reliably

Traditional car batteries should typically last between three and five years, depending on battery load and driving conditions the battery is subjected to. Also remember that cold mornings = harder/slower starts.

A common misconception is that temporary “rescue” batteries can be as reliable and last as long as specified replacement batteries for your car. This is not always true, because these are often times replaced as a temporary measure by a tow truck service in order for you to make your way home, and then some… Always make sure that your battery has the minimum CCA rating as specified for your car.

If you treat your car with the proper care and drive it in regular intervals, this can maximize the battery’s longevity. After all, no use is abuse!

Obvious benefits of replacing your own battery

Whether you decide to take your car to the dealer service department or feel the urge to replace the battery yourself, at least you can now be aware of what’s involved with choosing and swapping one out.

Don’t forget, we have ‘Battery replacement’ as a procedure in our manuals, and probably have one for your model. Our replacement guides have helped many people, and we’d love it if you’re next in line to save time, money and stress on something we know you’re capable of doing yourself.