Why won't my 911 battery stay charged?

A battery that won't hold a charge is almost as good as dead. It may be getting old. Or, you may have a habit of leaving your car doors open and the cabin light at night. Stop by for a free battery test at your local Firestone Complete Auto Care and learn more about your battery's charge.

What do you do with my old 911 battery?

We recycle it, taking care of both your car and the Earth.

How much do DieHard batteries cost for your Porsche 911?

Porsche 911 batteries can be affordable, especially when there's an available battery coupon. The best part is every DieHard battery comes with a free replacement warranty and extra coverage with DieHard Assurance.

What is the average lifespan of a car battery?

The typical 12-volt car battery may last three to five years, depending on the type of battery, the driving conditions, and how well the battery is maintained.

What is the white, crusty substance accumulating on my 911’s battery post?

The white, flaky stuff that can build up around your 911’s battery terminals is known as corrosion. Acid leaking from your vehicle’s battery post can have a chemical reaction with the air, leading to an accumulation of the white, powdery substance over time. Corrosion can affect the flow of electricity between your battery and the electrical system in your 911, possibly causing issues with electrical performance and starting. If left unaddressed for long enough, it may even cause your battery to prematurely fail.

What do I do about corrosion on my 911 car battery?

You can help prevent or get rid of corrosion by regularly inspecting and cleaning your battery terminals. Before cleaning your battery, see your 911 owner's manual to learn how to disconnect the battery cables. After disconnecting the cables, use a mixture of water and baking soda, a wire brush, and a rag to carefully clean the terminals.

Where can I find a battery for my 911?

You can shop for 911 batteries at your local Firestone Complete Auto Care, and our expert technicians will even handle the installation. Don’t have time to visit our store? Our Firestone Direct mobile vans can come to you for battery installations! Learn more about our mobile battery services.

1991 Porsche 911 Car Batteries

Get a New Porsche Battery

Get a Battery for Your Porsche 911

The middle of nowhere is the wrong place to have a weak battery. Shop replacement batteries for 1991 Porsche 911 today and schedule a quick installation at Firestone Complete Auto Care.

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The Right Battery Size for a 1991 Porsche 911

Researching battery replacements for your Porsche 911? Check the chart to find the right car battery size and cold cranking amps for your 911.

Battery	Engine	Warranty		Cold Cranking Amps
48H6	H6/3.3L	Replacement 36 months	Performance months	730
H6-AGM	H6/3.3L	Replacement 36 months	Performance months	760
48H6	H6/3.6L	Replacement 36 months	Performance months	730
H6-AGM	H6/3.6L	Replacement 36 months	Performance months	760

BATTERIES
H6/3.3L - Battery: 48H6 - Warranty: Replacement 36 months, Performance months - Cold Cranking Amps: 730
H6/3.3L - Battery: H6-AGM - Warranty: Replacement 36 months, Performance months - Cold Cranking Amps: 760
H6/3.6L - Battery: 48H6 - Warranty: Replacement 36 months, Performance months - Cold Cranking Amps: 730
H6/3.6L - Battery: H6-AGM - Warranty: Replacement 36 months, Performance months - Cold Cranking Amps: 760

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Buying a Replacement Battery for Porsche 911

Sadly, your Porsche 911 won't last forever. Neither will its battery. The average car battery lasts three to five years. Check your battery regularly and replace it as needed so it doesn’t leave you and your Porsche 911 stranded. Look out for symptoms of a faulty car battery. A slow engine crank, an illuminated check engine light or battery signal, bloated battery case, corroded battery posts, or weak lights can all be signs that your battery is on its last leg.

Or, you can get a complimentary battery check at your nearest Firestone Complete Auto Care. Our equipment can see how much charge is left in your battery. Drop in for a free battery check and, if needed, get your Porsche 911 a replacement battery. Automotive batteries are just one of our many areas of expertise. Our technicians are well-acquainted with Porsche’s service specs for 911 car batteries’ reserve capacities and cold cranking amps. Get help figuring out the battery size that matches your vehicle, and schedule an appointment today for a quick car battery replacement.

Is There a DieHard Battery for 911s?

We know what’s best for your Porsche 911, which is why we only carry top-of-the-line replacement parts and batteries. You need a reliable, durable and powerful battery in even some of the toughest conditions. DieHard batteries shatter expectations and house the latest technology to meet the increasing power requirements of new vehicles. A DieHard battery isn't an ordinary car battery. It's extraordinary. Buy a DieHard battery for your Porsche 911 and get behind the wheel with confidence. Why? Because performance will be there when you're counting on it. That's the kind of battery we deliver.

Caring for a New Porsche 911 Battery

Have you recently had a fresh battery installed in your Porsche 911? Congrats! Now, help it last longer and stay charged by caring for it from the get-go. Give your new battery a hand by limiting short trips, keeping your battery posts clean, and not playing the radio or using other electronics when the engine is turned off.

Commonly Asked 911 Battery Questions

Firestone Complete Auto Care has answers to your top car battery questions. If you have a battery question that's unique to your Porsche 911 battery, pay us a visit. Our expert techs have the answers you need.

Why won't my 911 battery stay charged? A battery that won't hold a charge is almost as good as dead. It may be getting old. Or, you may have a habit of leaving your car doors open and the cabin light at night. Stop by for a free battery test at your local Firestone Complete Auto Care and learn more about your battery's charge.
What do you do with my old 911 battery? We recycle it, taking care of both your car and the Earth.
How much do DieHard batteries cost for your Porsche 911? Porsche 911 batteries can be affordable, especially when there's an available battery coupon. The best part is every DieHard battery comes with a free replacement warranty and extra coverage with DieHard Assurance.
What is the average lifespan of a car battery? The typical 12-volt car battery may last three to five years, depending on the type of battery, the driving conditions, and how well the battery is maintained.
What is the white, crusty substance accumulating on my 911’s battery post? The white, flaky stuff that can build up around your 911’s battery terminals is known as corrosion. Acid leaking from your vehicle’s battery post can have a chemical reaction with the air, leading to an accumulation of the white, powdery substance over time. Corrosion can affect the flow of electricity between your battery and the electrical system in your 911, possibly causing issues with electrical performance and starting. If left unaddressed for long enough, it may even cause your battery to prematurely fail.
What do I do about corrosion on my 911 car battery? You can help prevent or get rid of corrosion by regularly inspecting and cleaning your battery terminals. Before cleaning your battery, see your 911 owner's manual to learn how to disconnect the battery cables. After disconnecting the cables, use a mixture of water and baking soda, a wire brush, and a rag to carefully clean the terminals.
Where can I find a battery for my 911? You can shop for 911 batteries at your local Firestone Complete Auto Care, and our expert technicians will even handle the installation. Don’t have time to visit our store? Our Firestone Direct mobile vans can come to you for battery installations! Learn more about our mobile battery services.