Best Car Batteries for Hot Weather: How We Chose & Why
We selected the most durable car batteries known to withstand hot weather specifically. All of the batteries on our list are AGM batteries, which are more advanced than conventional car batteries and are better suited for hot weather.
What Is An AGM Battery?
Unlike traditional flooded batteries, AGM (Absorbent Glass Mat) batteries have a special fiberglass mat to absorb the electrolyte solution. This design allows AGM batteries to store electrolytes in a “dry” state rather than liquid form. Since conventional batteries contain a lot of liquid solution, they need to be vented. However, if you tip it to the side, the electrolyte solution may spill. That’s not a concern with AGM batteries.
The venting technology in an AGM battery also helps keep some vapors in the battery, which makes it last longer than a traditional one – unless it’s been abused with excessive charging voltage. That makes the battery pressure rise above the limit, which can force the vent to open up. If this happens, an AGM battery may degrade quickly, leading to an early demise. Make sure to charge them correctly and test them.
Why Are AGM Batteries Best for Hot Weather?
Standard batteries harness electrical energy flowing from a positively charged material to a negatively charged material. Batteries capture that energy and use it to start your car. Extreme temperatures – both hot and cold – screw up the reaction, hindering your battery’s ability to function properly and shortening its useable life.
Cold weather slows the reaction while hot weather speeds it up, causing a shorter battery life and the battery liquid to evaporate at a faster rate.
However, AGM batteries tend to perform better in hot climates because of their inner workings, which are entirely different from standard car batteries. AGM batteries use a mesh made of absorbent glass to harness the energy, and despite working similarly to regular car batteries, their design renders them largely resistant to extreme temperatures.
AGM batteries have a few other benefits, including a high amp to weight ratio and better durability in the long run. Since the electrolyte is absorbed into a fiberglass mat instead of hanging lead plates in the electrolyte solution, AGM batteries are more resistant to vibrations than traditional batteries, reducing their lives. Most AGM batteries designed for high heat also have a higher electrolyte-to-lead ratio, boosting durability in hot weather.
Disadvantages of AGM Batteries
While AGM batteries will last longer, they will be a bit more money than a conventional battery. Still, we believe the extra cost is worth it if you want a car battery for the summer months and warm climates.
Best Car Batteries for Hot Weather: The List
#1: DieHard Platinum AGM (370 to 900 CCA)
DieHard is best known for its long-lasting batteries, and the Platinum AGM provides about double the life versus a standard flooded battery. The DieHard Platinum AGM is ideal for newer vehicles, as it’s designed to accommodate the electrical demands of things like heated seats, navigation, and modern start/stop systems.
Optima batteries are flashy and pricier than their competition. Still, you’d be hard-pressed to find a better AGM battery on the market, especially if you drive a truck or an SUV. If you are towing a boat or hauling heavy trailers, these batteries can handle it, especially during the summer months.
Optima batteries use 99.99% pure lead, which conducts electricity faster than traditional lead alloy. Comparing the conductivity of 99.99% pure lead to lead alloy is like comparing a kitchen faucet to a fire hydrant. Pure lead is far faster and more efficient. In addition, Optima batteries retain their charge longer and dissipate more energy at once, providing maximum power over a more extended period than traditional batteries.
Optima batteries are mostly known for their Spiral Cell Technology, meaning the pure lead is wrapped up into tightly wound cylinders, enclosed by a strong, sealed polypropylene case. This design better protects Optima batteries from the rumble and tumble and vibrations that wear down traditional batteries.
Like the previous Optima battery on our list, the ACDelco Gold (aka Professional) is an excellent choice for heavy-use vehicles. The high-density plate oxide provides maximum power-per-pound and a dependable “high cycling” service. This battery also features a leak-proof and pressurized valve system to prevent acid damage on the terminals.
Where to buy: The ACDelco Gold Professional AGM is available for around $200. All ACDelco Gold batteries come with a three-year warranty.
#4: Bosch Platinum AGM Series (440 to 650 CCA)
The Bosch Platinum AGM Series is thick, well-sealed, and has a nice carry handle. It’s ideal for commuting in heavy, stop-and-go traffic and will handle today’s modern start/stop and regenerative braking systems.
Bosch stands behind these batteries with a four-year free replacement warranty, which is longer than the ACDelco battery above. Bosch also offers free roadside assistance for the first three years of ownership.
Where to buy: This one can be a little harder to find, but you can find a standard size on Amazon.
#5: ACDelco Advantage AGM (325 CCA)
Like the other batteries on our list, the ACDelco Advantage AGM is better at handling road vibrations than a standard flooded battery. The ACDelco Advantage AGM is known for its corrosion resistance and minimal water consumption. It’s also slightly more affordable than the other batteries on this list.
Regardless of the battery you choose, it’s best to consult your mechanic before replacing the battery in your car. You shouldn’t replace your doctor or dentist with a few Google searches on medicine, and then think you can diagnose yourself. Likewise, you shouldn’t supersede your mechanic’s expert advice by self-diagnosing any serious problems with your car.
In the meantime, this helpful guide will advise you on things you can do to prolong the life of your vehicle. However, when in doubt, always consult a trusted mechanic.
Alan Marek is a lifelong car enthusiast and the founder of PartCatalog, a Texas-based e-commerce auto parts retailer. Growing up, he enjoyed working with his hands and being under the hood of his car. Marek began selling auto parts on eBay Motors, eventually launching his own store with PartCatalog.