The surest sign of battery trouble is that your car is slow or hard to start. The battery is powering the starter, which must crank the engine against the compression in the pistons. This requires lots of power, particularly in vehicles with diesel engines. Worn batteries may recover temporarily with a jump start, but a battery that continually needs more than one jump-start is done.
Don’t take any risks. The modest cost of replacing the battery is well worth avoiding the stress caused by a roadside or parking lot breakdown.
Car and truck batteries are either conventional lead-acid or the more advanced absorbent glass mat (AGM) design commonly seen in vehicles that are equipped with engine stop-start systems. If you are unsure of the size, amp-hour rating, or cold-cranking amps needed for your vehicle, check the existing battery’s label or consult your manufacturer owner’s manual.
Check Under the Hood
Being attentive to your battery’s maintenance and mindful when the time for replacement is approaching will ensure that you can choose a replacement on your own terms, including properly researching and conveniently scheduling.
Test Batteries Annually
Inspections should be part of an owner’s routine maintenance, but it is especially important to check before taking a long road trip.
Car batteries typically last from three to five years, according to AAA, spanning from 58 months or more in the farthest northern regions of the U.S., down to less than 41 months in the most southern regions.
Though almost all of today’s car batteries are “maintenance-free,” we recommend having your battery load-tested by a mechanic annually once it is 2 years old if you live in a warmer climate or 4 years old if you live in a colder climate. Doing so tests its ability to hold voltage while being used, and the results will let you know when it’s time to start shopping.
The battery’s age is also a strong indicator that it’s time to consider a replacement. The date can be found on a sticker affixed to the top or side of the battery. A battery made in October 2021 will have a numeric code of 10/21 or an alphanumeric code of K-1. “A” is for January, “B” is for February, and so on (the letter “I” is skipped).
A Battery Should Fit Your Car and Driving Needs
Car batteries come in many sizes. Among those that we have tested, there’s significant variation in which is the top performer from year to year, and from size to size. This makes it impossible to make simple recommendations by brand or model. It also means you shouldn’t assume that buying the same battery model you are replacing will get you the same results.
Make sure you get the right size and terminal locations (or type) for your vehicle. Check your owner’s manual or an in-store fit guide before shopping.
In some cases, owners can replace an AGM battery with a traditional flooded one to boost longevity in hot climates, but it’s best to consult a mechanic first. Many cars come with AGMs to support an increasing array of electrical components, and the charging system may be configured specifically for an AGM battery.
Make Sure It’s a Fresh Battery
Batteries lose strength over time, even when in storage. For optimum performance, purchase one that is less than 6 months old. Three months is even better. Most have a shipping code on the case. Some use a letter for the month (“A” for January) and a number for the year (“1” for 2021); others use a numeric date.
Recycle Your Old Battery
A battery’s toxic lead and acid can easily be recycled, and most retailers will dispose of the old one for you. When buying a new battery at a store, you will probably pay an extra charge that will be refunded when you return the old battery.
It is important to choose a battery with the longest free-replacement period you can get. A battery’s warranty is measured in two figures: the free-replacement period and the prorated period—which allows only partial reimbursement.
A code of 24/84, for example, indicates a free-replacement period of 24 months and a prorated warranty of 84 months. But the amount you’ll be reimbursed usually drops off pretty quickly once you’re in the prorated period.
Be aware that signs of neglect—such as low water levels and improper installation—can void a warranty. So can heavy-duty use, such as for high-end car audio and marine applications, if the battery is not recommended for it.
Pick The Best Battery Life.
You want a battery that won’t send you back to the shop. When it comes to longevity, not all batteries are created equal.
Car batteries keep your car running longer by constantly recharging. Unfortunately, some batteries don’t take this constant flow of new energy too well. These batteries decrease in power with each recharge until they’re dead weight under the hood. For more details on how batteries work, check out How Does A Car Battery Work?
If you’re worried about how long your new battery might last, compare battery life, reserve capacity, and cold-cranking amps test scores
The battery-life test is the most important and measures a battery’s ability to withstand being recharged thousands of times over multiple months.
The reserve-capacity test measures how long a battery can supply power after its charging system fails.
Finally, the cold-cranking amps test is important if you live or drive in cold climates. It measures the current available at 0º F to make sure you don’t get stranded in sub-zero temperatures. Brrr!
Opt For the Longest Battery Warranty.
You want a battery that’s guaranteed. Not only does a good warranty demonstrate a manufacturer’s confidence in their product, but it also helps protect you if anything goes wrong.
All things being equal, you want the battery with the longest free replacement period. Most battery warranties have two parts: a free-replacement period and a limited performance warranty. Although you may get partial reimbursement during the latter period, the amount you’ll be reimbursed upon battery failure won’t match that of a free replacement warranty.
If your battery is under warranty, make sure to take a peek at its condition. Signs of neglect such as low-water levels or improper installation can void some warranties. By getting one of our expert technicians to install your new battery and keep it running smoothly with regular checkups, you could save yourself a headache (and significant expense) down the road.
Comparison of the best car batteries for 2022
|Best Battery||Make||Model||Cold Cranking Amps||Reserve Capacity||Weight||Features|
|Best car battery overall||Odyssey||Extreme Series 35-PC1400T||850||65 aH/130 minutes @ 25-amp draw||50 pounds||Blue blood AGM rated highest among dozens tested in Consumer Reports labs, with “no discernible flaws.”|
|Best affordable car battery||Ever Start||Maxx 35N||640||44 aH (est)||38.1 pounds||Conventional lead-acid outperformed batteries costing two or three times as much in lab tests. Three-year full replacement warranty.|
|Best car battery for pickup trucks||Diehard||Gold 50865||850||70 aH est/150 minutes @ 25-amp draw||45.2 pounds||Balanced performance at a reasonable price, just like a good working pickup.|
|Best car battery for track cars||Braille||Lightweight AGM||425 to 500||21 to 31 aH||15 to 21 pounds||From a company famous for race car batteries, Braille’s less expensive products deliver the best power-to-weight ratios in the consumer market.|
|Best car battery for a lot of accessories||Deka||Intimidator AGM Deep Cycle Series 8A31DT||800||105 aH/200 minutes @ 25-amp draw||69 pounds||Should power headlights and a loud car stereo for more than 3 hours with the engine off and still safely recover.|
|Best car battery for hot and cold climates||Optima||Yellowtop D51R||450||38 aH/68 minutes @ 25-amp draw||26 pounds||Excellent balance of power and durability in extremes of both heat and cold, but mediocre reserve capacity.|
|Best car battery for tech geeks||Antigravity||Re-Start Lithium-Ion||425 to 800||24 to 60 aH||9.8 to 19.5 pounds||Pioneer in lithium portable power storage brings its technology to 12-volt car batteries. Guaranteed to never drain below the point where it can’t start your car.|
|Best car battery for cheapskates||Ever Start||Value VP-35||490||35 aH (est)||38.2 pounds||Venerable capped lead-acid tech delivers excellent cranking power. One-year full replacement warranty, but with proper care and feeding, it should keep you rolling for years.|
How long does a car battery last?
Batteries for cars, trucks, and SUVs typically remain in peak condition for three to five years, but they gradually deteriorate and lose charging capacity until there’s not enough juice to start the engine. Vehicle owners should periodically check their battery’s condition.
After three years, it’s best to test annually at the least. An overall inspection of the battery and its connectors is recommended for every oil change. If a car battery test proves deterioration, or if your vehicle’s lights or electronic devices are showing signs of age such as appearing dim, it may be time for a replacement.
How do I know if I need a new car battery?
If the battery charge warning light illuminates on your dashboard, or if the starter motor turns the engine over slowly, chances are good that it’s getting near time to replace your battery. In older vehicles, dim incandescent headlights when the car is idling indicates a weak battery.
Or, if your vehicle’s headlights seem dim at night, rev the engine while in a park or neutral. If the headlights get brighter as the engine revs, the vehicle’s battery is likely failing. If you fit a new battery and find that it soon goes dead, you may need a new alternator, the device with charges the battery while the engine is running.
Why does a car battery lose charge?
Batteries use an electrochemical process to generate electricity from stored chemical energy. They have a finite number of charge and discharge cycles until the amount of energy a battery can store and the maximum power it can output begins to degrade.
Cold and hot temperatures will cause batteries to degrade faster, but any battery that’s unused will discharge (as many office-commuting drivers learned in 2020). Batteries in vehicles that are solely used for short trips may never have the chance to fully recharge, which only causes the battery to age faster.
Other factors, such as vibration from rough roads or loose hardware, a malfunctioning vehicle charging system, and humidity can play havoc with batteries.
What type of battery do I need? How many cranking amps do I need?
When choosing the right battery for your vehicle, the battery type, group size, terminal configuration, and cold cranking amps (CCA) or amp-hour (Ah) rating must be considered. The group size is based on your vehicle’s model and engine type and takes the orientation of the battery terminal and the exterior measurements of the battery case into account.
All batteries are assigned a group number that is visible on the side or top of the case. Make sure that the group size number on the new battery matches your existing vehicle battery and that the CCA or Ah matches the vehicle manufacturer’s specifications.
Installing an incorrect battery could cause damage to the vehicle’s electrical system, for example, if the terminal locations create a short circuit with nearby components. Consult your vehicle’s owner’s manual if you are uncertain about which battery to buy.
What’s the difference between a starter battery vs. a deep cycle battery?
Starter batteries are designed to provide a quick and short burst of energy to start an engine efficiently. Once the engine is running, the alternator begins producing current to serve the vehicle’s electrical demand while simultaneously recharging the battery.
Traditionally, deep cycle batteries provide greater long-term energy delivery but far less instant on-demand power. This makes them preferable for golf carts, electric trolling motors for boats, off-grid energy storage, RVs, and campers.
There is, however, an emerging class of batteries that perform both as a starting battery and a deep cycle battery. A few manufacturers make models aimed at the marine market that feature two sets of terminals, one for the starting circuit and one for the trolling motor.
That technology has moved into the automotive realm. Many companies are producing batteries with huge reserves of power and impressive cranking grunt on demand for starting a vehicle. These are generally more expensive and buyers may have to do a bit of research to make sure this type of battery is compatible with their vehicle.
Is a cheap car battery worth it? Are expensive batteries really better?
Not all cheap batteries are bad, but generally speaking, more expensive batteries will be of higher quality. Most cars and trucks use lead-acid wet cell batteries, which contain lead plates separated by material layers that slow the flow of ions between the plates.
Higher quality batteries will use rubber between these plates, but some cheaper batteries skimp and use PVC or other materials. The wiring may also be of lower quality in cheap batteries to save on production costs. These can wear out faster and potentially leak.
Absorbent Glass Mat (AGM) batteries use a layer of fiberglass, as the name implies, to separate the plates and seal them off entirely. These batteries are tightly packaged inside and fully sealed internally, making them impact-resistant, safer, and more powerful. They cost significantly more to make and to replace. An AGM battery can cost more than $300 before installation, which is almost double what a good lead-acid battery costs.
What is a cold cranking amps rating?
A vehicle battery’s cold cranking amp (CCA) rating is an industry-standard that defines how well a battery can start a vehicle in cold temperatures. The battery’s CCA rating measures how much electrical power a battery can provide at zero degrees Fahrenheit for 30 seconds while maintaining 7.2 volts of power.
A battery should have at least one cold-cranking amp for every cubic inch of engine displacement or two cold-cranking amps per cubic inch of displacement for diesel. Never install a battery with a lesser CCA rating than what the vehicle manufacturer recommends because it could cause issues with the vehicle’s electrical system.
However, installing a battery with a higher CCA rating will work, but may cause the battery to have a shorter life in hot climates. Note that CCA is not to be confused with cranking amps (CA) ratings, which are based on a less complex test that produces inflated or inaccurate numbers.
What are Amp-hours?
The Amp-hours (Ah) rating is the specific measurement of a battery’s capacity that breaks down how long the battery can produce one amp of current per hour before it loses power. For example, a car with a battery rated at 50 Ah will provide a current of 1 amp for 50 hours, 50 amps for one hour, or a combination of amps and hours that will equal 50 amp-hours.
Vehicle battery Ah ratings vary widely and could range anywhere between 50-500 Ah. When looking at deep cycle batteries, the amp hour rating will be labeled on the battery or sales packaging or paperwork.
If you are unable to find a vehicle battery’s Ah rating, you may be looking at a starting battery, which does not provide continuous power in amp-hours. Knowing how many amp hours your vehicle requires for optimum performance is key.
Since higher amp hours mean higher capacity, heavier-duty vehicles should utilize batteries with higher amp-hour ratings. If you are unsure of what amp hour rating is required for your use, consult your vehicle’s owner’s manual.
Don’t forget to include any vehicle modifications or add-ons that would increase power draw, like winches or upgraded audio systems. To do this, calculate the run time of your accessories by dividing the battery’s Amp hour rating by the amp draw of each accessory. You may need to divide the accessory’s wattage by the voltage to get its amp hour rating.
What is a battery’s C rating?
Car batteries are subjected to constant current discharge. A C rating is a measurement of the rate of time that it takes to completely charge or discharge a battery. For example, a C1 rating means that the battery current will discharge its entire capacity in one hour–that is, if you leave the vehicle’s lights and accessories on while the vehicle is not running.
The charge capacity is defined as Ampere or Amp-hours (Ah). Temperatures also impact how quickly a battery can charge or discharge. A battery with a higher C rating will deliver more energy for higher performance.