Diehard Battery Reviews

​A faulty car battery can cause some pretty big issues. Everyone has been late for work or missed an appointment because they were trying to get their battery started. Or if you have a car you haven’t used in a while, the battery may need a jump to get it going. Either way, it can cause a lot of frustration and disappointment.

The only way to combat these frustrating moments is to buy a battery that is high-quality, strong, and long-lasting. A DieHard battery is known for its high-quality and reliability, so they are definitely a battery worth the investment. Here are a few DieHard batteries that can take on a heavy load while still keeping an adequate charge.

Our Top Rated DieHard Battery Reviews for 2020

#1st Rated
 DieHard 38217 Group 49 lead_acid_battery

DieHard AGM Group 49 Battery

#2nd Rated
DieHard 38217 Group 49 lead_acid_battery

DieHard AGM Group 34 Battery

#3rd Rated
DieHard 38217 Group 49 lead_acid_battery

DieHard AGM Group 35 Battery

1. DieHard AGM Group 49 Battery - Top Pick for 2020

The perfect choice for trucks and RVs, the DieHard AGM Group 49 Battery can handle heavy loads. Considered one of DieHard’s top-rated car batteries, this battery is a great choice for an F150, especially when you consider the life expectancy that is twice that of a regular lead-corrosive battery. If you are hauling over the load limit, this battery will have no problem keeping up an adequate charge.

With high 850 CCA ratings, the DieHard AGM Group 49 Battery stands above typical heavy-duty batteries. The AGM configuration allows it to keep up support in harsh conditions and protect it from any type of break. The AGM design also can withstand elevated temperatures and an increased demand for accessory power using the full lineup of AGM technology that provides a longer life and more power.

The Diehard AGM Group 49 Battery is spill-proof and maintenance-free. You can mount it in pretty much any position, and it is perfect for many domestic and import OEM applications. This is a great battery choice for Volvo, Volkswagen, Saab, Porsche, Mini, Mercedes Benz, Jaguar, Chrysler, BMS, and Audi vehicles.

This battery is not only a good choice for trucks, RVs, and marine applications, but it can also be used for tuner cars, performance cars, watercraft, and off-road vehicles working well will intense vibrations during typical use.


  • This battery has a nice long lifespan along with a smart design
  • It works really well in bad and extreme weather
  • It protects its internal parts well


  • The battery is a little on the small size

2. DieHard AGM Group 34 Battery

Perfect for your 4 x 4 or SUV, the DieHard AGM Group 34 Battery is both substantial and reliable. This is a great battery for any type of vehicle providing lots of power. With an extraordinary and extreme appearance, this battery is safe to use in harsh climates and will last you a long time.

This battery is a great choice for RVs, trucks, and marine applications, plus the DieHard AGM Group 34 Battery also works well for tuner cars, performance cars, watercraft, and off-road vehicles where the battery will experience intense vibrations during regular use.

 With its outstanding AGM design, this battery can easily withstand elevated temperatures, harsh weather conditions, and an increased demand for accessory power. Using AGM technology, the DieHard battery will give you a longer life and lots more power than the typical battery.

This spill-proof battery has a 55 AH rating and is also maintenance-free. The Group 34 Battery is also mountable in any position and meets the needs of many domestic and import OEM applications.

This is a great batter for start-stop applications as well as Volvo, Volkswagen, Saab, Porsche, Mini, Mercedes Benz, Jaguar, Chrysler, BMW, and Audi vehicles


  • This is a very durable battery that lasts a long time
  • It can power lots of different vehicles
  • It comes with a three-year warranty


  • This battery is not compatible with every vehicle
  • It is not a deep-cycle battery

3. DieHard AGM Group 35 Battery

With a lot more vibration assurance than a typical battery, the DieHard AGM Group 35 Battery is designed to shield battery execution. The design is also spill-proof that gives it more protection than most other modern electronic hardware. It also has an incredibly long life when you compare it to other lead batteries that you can buy.

Perfect for RVs, marine applications, and trucks, the DieHard AGM Group 35 Battery also features powerful negative and positive plates that prevent a life-threatening electrical short. With the improved electrolyte suspension framework, it can also absorb more electrolytes ensuring the safety of all its internal parts. With a predominantly AGM configuration, it also comes with expanded power.

This battery is not only well-suited for trucks and RVs, but also tuner cars, performance cars, watercraft, and off-road vehicles that go through intense vibrations in the course of normal use. The DieHard is spill-proof and maintenance-free, plus you can pretty much mount in any way you want.

The DieHard AGM Group 35 Battery is a direct fit for most domestic and import OEM applications. In particular, this battery is great for rough terrain vehicles and anything that will be experiencing extraordinary use or vibrations.

The DieHard AGM Group 35 Battery is a direct fit for most domestic and import OEM applications. In particular, this battery is great for rough terrain vehicles and anything that will be experiencing extraordinary use or vibrations.


  • This is a powerful and durable battery
  • The AGM configurations make it reliable and long-lasting
  • It protects its internal parts really well


  • It can be hard for some users to install

4. DieHard 38188 Advanced Gold AGM Battery GP 34R

A great choice for off-road vehicles and performance cars, the DieHard AGM Battery GP 34R also works well on vehicles like tuner cars and watercraft where they need to withstand strong vibrations. Featuring a full-outline negative and positive plate design, the GP 34R includes a structure that stops electrical shorts from happening occurring when the battery is used.

The electrolyte suspension framework on the GP 34R is used inside the battery enabling electrolytes in the battery to work without a block. Unhindered, the electrolytes move around and protect the internal parts of the car battery from getting destroyed.

There is also protection for the outside of the battery which shields it from any moves or shakes that can happen inside the battery. With its ability to withstand increased temperature and accessory power demands, the GP 34R is designed to give you a long life and lots of power. The GP 34R is perfect for RVs trucks, and marine applications.

The GP 34R is also maintenance-free and spill-proof allowing you to mount it in pretty much any position. This battery has a CCA 775 and 55 AH rating allowing it to meet the needs of many domestic and import vehicles like Volvo, Volkswagen, Saab, Porsche, Mini, Mercedes Benz, Jaguar, Chrysler, BMW, and Audi.


  • The battery has a sleek and simple design
  • It is quick to start up and maintenance-free
  • It protects its internal parts really well


  • It does not work well in large vehicles
  • It can sometimes stop working if the weather is cold

5. DieHard AGM Group 48 Battery

Another great choice for your Volvo, Chrysler, or Volkswagen is the DieHard AGM Group 48 Battery. With a CCA 60 and 70 Ah rating, the Group 48 Battery is well-designed and spill-proof. Complete with full edge negative and positive plates that stop the battery from causing an electrical shock.

With an improved electrolyte suspension framework, the Group 48 Battery can protect its internal parts while assimilating more electrolytes. It also has multiple vibration insurances that protect the execution of the battery. This is a maintenance-free battery that will fit many types of domestic and import OEM. applications.

This battery is well-suited for tuner cars, performance cars, watercraft, and off-road vehicles as well as trucks, RVs, and marine applications that have to withstand intense vibrations during regular use. 

The outstanding AGM design of the Group 48 Battery can withstand increased temperature conditions and accessory power demands. With a full-plate of AGM technology, you get a design that gives you a longer life and more power.


  • It comes with an electrolyte suspension system and spill-proof design  
  • This is a durable and long-lasting battery
  • It features vibration protection to help extend the life of the battery


  • It is not eight-inches tall as advertised
  • There is a protrusion on the POS cable that needs to be cut off

Choosing The Best Battery For Your Car: The Ultimate Buying Guide

A specific type of battery is required for each vehicle since they need different amounts of power and all have different sizes. Make sure to check the maintenance guide for your vehicle to see which type of battery is best suited for your car. Here are a few additional tips for choosing the right battery for your vehicle.

- If you don’t have the maintenance guide, just take it to your mechanic and they will be able to tell you what type of battery you need for your car.

- Since climate causes a huge impact on how your car battery works, always choose a battery that is appropriate for your local weather. If you live in a cold area, buy a battery with an “N” on it for northern climates. Hotter climates want a batter with an “S” label for southern climates.

- If you do a lot of off-road driving, look for batteries that can withstand constant vibrations.

Look For Maintenance-Free Batteries

As technology continues to develop, many of the car batteries on the market are now maintenance-free, so they won’t need a lot of special attention. There are some, however, they will still need periodic filling with water, but in general, buying maintenance-free batteries when possible will help to avoid issues in the future.

Good Reputation

Always check reviews before you buy a battery to see what others have thought of the product. It is super easy to get great information on consumer reports sites or sites that sell the product to see how others have felt about the battery’s performance. You can tell a lot from someone’s review like whether it is the best deep cycle battery or not or if it’s very reliable.

Old Batteries

As you store a battery, it loses its strength. Always buy a new car battery that was made in the last six months to ensure that you are buying the best car battery at that time. On some car batteries, you will see a code that lets you know the date of the battery. For example, “A” will stand for January while “B” will stand for February and so on.

Maintain Your Battery

Make sure you pay attention to the maintenance of your battery and remember when it is time to replace it. This allows you to buy a battery that you want, not just want the repair shop puts in for you, so make sure you do the right research and schedule accordingly.

Annual Testing

As a part of your routine maintenance, an annual inspection should be done as well as a quick check before you take any long road trips.
According to AAA, a car battery should last between three and five years. Regionally, you should get at least 58 months, if not more, in the northern parts of the country, but only get 41 months in southern states.

While most batteries are now maintenance-free, you still should have a mechanic test your battery load each year once the batter is two years old if you live in a warm climate, and at four years for those living in colder areas. This test allows you to see the battery’s ability to hold voltage while it is being used and can tell you when you need to get a new battery.

The age of the battery also tells you when you should buy a replacement. You can find the manufacture’s date on a sticker found on the side or top of your battery.

Fitting Your Car and Driving Needs

Car batteries come in many sizes, but did you know that there is also a lot of variation from year to year as well? This can make it hard to find easy recommendations for your vehicle by model or brand. Also, don’t assume that by buying the same type of battery you had before to replace it will give you the same results. Here are a few tips to make sure you find a battery that fits both your car and driving needs.

- Look at your owner’s manual to ensure that you are getting the right terminal locations and size for your car.

- In some cases, you are able to replace your AGM battery with a regular flooded battery to increase its longevity if you live in a hot climate, just make sure you ask a mechanic first. There are also cars that come with an AGM battery that supports a wide range of electrical parts, plus the charge system can be specifically designed for the AGM battery.

- Always use a fresh battery. Since a battery can lose its strength over a long period of time, always purchase a battery that is less than six months old with three months being the preference. Even if it's been stored and not used, it can still lose strength.

- Since the toxic acid and lead in a battery can be recycled easily, most retailers will take care of disposing of the old battery for you. When you buy your new battery at a store, there should be an extra charge that you can have refunded when you turn in your old battery.

- Another important consideration when choosing a car battery is to find the one that has the longest free-replacement period possible. You can measure a battery's warranty in two ways through either the prorated period, which gives you a partial reimbursement only or a free-replacement period where you get an entirely new battery.

If you see a code of 24/84 on the battery, it means you get a 24-month free-replacement period and an 84-month prorated warranty. Keep in mind though that the amount you get reimbursed will typically drop off quickly as you enter into the prorated period.

- Also, remember that signs of neglect like improper installation and low water levels will void a warranty. This also goes for heavy-duty use like marine or high-end car audio applications when the battery states that it does not recommend that type of use.

Battery Types

Lead – Acid Battery

Widely used and most common, lead-acid batteries need to be topped off with water in its electrolyte solution every so often since the battery’s power source has liquid in it. With how quickly technology changes, we now have new lead-acid batteries that do not need more water like the regular flooded cell ones. With these new batteries, the manufacturers have designed them to retain their fluid for the life of the battery, and they have caps that are not meant to be disconnected.

You will find that a lead-acid battery costs a lot less than an AGM battery, which is why you see them used a lot more often. Keep in mind though that a lead-acid battery will not be able to hold its charge for as long, plus these batteries have a low ability to tolerate deep discharges.

Absorbed Glass Mat (AGM)

AGM, or Absorbed Glass Mat, batteries typically are used in vehicles where their smart features and outstanding features are needed for their power and reliability. When you compare them to a typical car battery, an AGM battery can better withstand repeated draining and recharging cycles. They also come with smart features including power outlets for electronic devices, stop-start systems that will save on fuel, convenience features, and electronic safety features.

When purchasing an AGM battery, you will typically pay quite a bit more than you would for a lead-acid battery. This is an especially smart choice for anyone that leaves their car sit for a long period of time allowing the car battery to lose its charge. They also have a design that tolerates deep discharges better and are more likely to completely recover.

Considerations When Choosing a Car Battery



Available in several different sizes, a car battery needs to be chosen for the specific model and make of your car. The size of a battery is divided into a different group that each have their own letters and numbers that help to designate them. There are some cars that can accommodate more than just one size battery, but it is still important to find a battery that is approved to be used in your vehicle. Make sure to check the specifications of the manufacturer to find out which one is right for your car.

Cranking amps (CA)

CA measures the starting power of a battery. Your owner’s manual should list your vehicle’s requirements when it comes to a CA rating, so you can choose the right option for your car.

Cold-cranking amps (CCA)

Measuring the starting power of a battery in cold weather, CCA is a rating that tells you how many amps a 12-volt battery can give you for 30 seconds at 0℉ and also keeping the voltage steady at 7.2 volts. This rating is especially important for those that live in colder climates. Remember that you want a battery that has the highest possible CCA rating that meets the requirements of the car manufacturer.

Battery reserve capacity

The capacity of the battery’s reserve tells you how long it will give you power in the event that you leave on the headlights or other accessories or if the charging system on the battery fails. You want a battery that will give you about 1 ½ hour of reserve capacity. If you have a high performing battery, you want at least two hours of reserve capacity.


If you want the best car battery, it should be pretty much maintenance free meaning that you won’t need to add liquid to it. If you definitely want the least amount of maintenance as possible, look for a battery that is completely sealed.


You want your car battery’s warranty to be as long as possible. Look for models with a three-year replacement warranty or even longer if you want more security. You can also choose a battery that gives you a prorated refund if the battery fails in a specific time period after the warranty is over.


car batteries can be pretty heavy, some as much as 40 pounds, they can be difficult to carry and maneuver. For those that want to install the battery themselves, look for a battery that comes with a handle that makes it easier to lower it into the tight area of a car engine.

Tips to Extend Your Car Battery’s Life

- When the car is not running, don’t use the AC, radio, or lights to help prolong the life of your car battery

- Use terminal protector spray occasionally to keep the negative and positive terminals on your car battery from corroding

- Every so often, take the scenic route. You can prolong your car battery’s life by driving your car for long periods now and then.

- Wear rubber gloves and safety eyewear when working on or replacing your car battery

- Park inside a well-insulated garage in the winter if you can to help protect the battery.


How Long Will An AGM Batteries Last?

Typically, an AGM battery will last between three and five years. By maintaining and using it correctly, you can extend the life expectancy up to eight years with some AGM batteries lasting as long as ten years.

Should You Jumpstart an AGM Battery?

In the event of an emergency, it is possible to jumpstart an AGM battery. Keep in mind that the battery may not become fully charged because of the alternator, but you can probably use it for a couple of hours after you jump start it.

Can an AGM Battery Become Damaged from Overcharging?

Yes, you can damage the battery if you overcharge it. Make sure to use a particular trickle battery when charging AGM batteries. If you use a regular battery charger, it can cause an AGM battery to become overcharge which can lead to permanent damage.

Should You Use A Regular Battery Charger for An AGM Battery?

No, it is not advised to use a regular battery charger with an AGM battery. Like a gel battery, an AGM battery needs a special trickle charger that is different than the regular chargers that one would use for a flooded battery. AGM batteries need to be charged slowly, which requires a special charger that can charge them completely.

Which Size Battery Should I Choose?

The easiest way to determine which battery size you need is to check the current battery in your car for its size. Look at the “Ah” number on the current car battery. If you find that the current battery is from the factory, then look for a larger capacity battery to replace it with.

How Can I Tell If My Car Battery Is Damaged?

To tell if your car battery is damaged, look for these signs:

- The engine will crank but will not start
- The car won’t start and both the headlights and the radio do not turn on
- The vehicle will start sometimes but sometimes won’t
- It is necessary to jump the battery several times

How Long Should A Battery Last?

The best quality car battery should last between five and ten years. If you want to increase the battery’s lifespan, make sure you do not run it when it is at a low charge.

Do You Need to Fill an Advanced AGM Battery With Water?

Since an advanced AGM battery is sealed and maintenance-free, it is not possible to fill it with water. All you can do is clean the terminals once a year to make sure they always have a good charge.

Can a car battery be affected by temperature?

The capacity of a battery will increase in hot temperatures, but the battery life will actually decrease. When it’s cold, the battery will have a lower capacity, however, it will usually last longer.

Can a car battery freeze?

Yes, a car battery can freeze after it is left out in the cold thanks to the mix of sulfuric acid and water that is found inside the battery.

Is their liquid in a car battery?

There is a mix of sulphuric acid and water inside your car battery. The acid’s concentration is directly proportional to the charge inside your battery.
You are pretty much assured to replace the battery in your vehicle at least once during the time that you own it.

Having a dead battery can become a big program, so it’s in your best interest to make sure you buy one that won’t cause problems. By choosing a DieHard Battery, you will ensure that you have a long-lasting and reliable battery that is also frustration-free.

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