Do You Know How Long Does A 9v Battery Last?

One of the most popular batteries in use is the 9V variant. And, I can understand if you have asked yourself, how long does a 9V battery last?

Usually, a 9V NiMH battery can last up to 4 hours with continuous uses. At the same time, a 9V Li-ion battery can provide enough juice for about 7.5 hours. 

But you must keep in mind that the assumption varies based on lots of different factors. Brand and chemistry are the main variables here. Read the full article to get a clear and precise answer to the question. 

So, How Long Does A 9v Battery Last?

I have already given a rough estimate regarding the service life of this particular battery type in the introduction. 

Here, I am going to explain more on the topic in two main parts. One will be giving you an idea about their lasting period in usage and another in storage. 

How Long Does A 9-Volt Battery Last in Use?

It is possible to calculate the runtime with simple math. All you have to do is find out the battery capacity and power demand of the device you want to use. 

Let’s say that your 9V alkaline battery is rated at 600mAh and the required device draws a maximum of 25mA current.

Divide the capacity by the current requirement of the electronic device, and you will get the runtime.

Here, 600/25 equals 24. So, you will be able to run the device continuously for 24 hours in theory.

On the other hand, the same type of lithium battery has a higher capacity. Let’s say yours have 1000mAh.

In that case, you will get almost 40 hours of juice. But nothing is that efficient. Therefore, you will get less runtime. 

Lastly, I want to give you the link to a 9V battery calculator. It can do the calculation automatically. 

Providing the battery capacity and your device’s power requirement, you can know the runtime. 

Below, I have prepared a table showing different runtime for different battery chemistry. The values here are average; they vary from brand to brand.

Battery ChemistryRechargeableAverage CapacityRuntime (Connected to a 10Ah Device)
Nickel-Cadmium (NiCad)Yes120 mAhApprox. 12 hours
Nickel Metal Hydride (NiMH)~300 mAhApprox. 30 hours
LiPo520 mAhApprox. 52 hours
Li-ion620 mAhApprox. 62 hours
Li-ion Phosphate~320 mAhApprox. 32 hours

AlkalineNo550 mAhApprox. 55 hours
Zinc-Carbon400 mAhApprox. 40 hours
Lithium1200 mAhApprox. 120 hours

How Long Does A 9-Volt Battery Last in Storage?

9V alkaline batteries usually last almost 5 years without dropping their voltage. Most popular brands have such capability. 

But some of the expensive alternatives come with more shelf life than usual. For example, you can store Ultralife Lithium 9V for almost 10 years. 

Almost double storage time benefit is possible because of the Li-ion technology. 

For powering critical instruments, I think that you should go for more expensive Lithium 9-volt batteries instead of alkaline ones. 

And, you can use Ziploc bags to store the batteries after taking them out from the sealed packaging. 

Frequently Asked Questions (FAQs):

Which 9V battery lasts the longest?

According to some independent reviewers’ testing, Ultralife 9-volt has the most runtime compared to other popular alternatives. 

How long does a 9V battery last in a smoke detector?

If you install an alkaline battery, it will last somewhere between 12 and 18 months. And, it can be up to 5 years in case of using lithium-ion ones. 

How long does a 9V battery last Arduino?

Depending on the project type and its consumption level, the most expensive lithium-ion 9V batteries can last from 24 to 48 hours. 

How long does a 9V battery last on an electric fence?

If you are looking for a non-rechargeable option, a 9V battery will be the best solution which can last up to 9 months. But the durability varies a lot depending on the brand and battery capacity. 

How long do 9V batteries last in active pickups?

For single active pickups in your guitar, a 9V battery can easily last for around 3000 hours. But expect the durability to be half or less for two pickups. 

Do 9-volt batteries expire?

Yes, all batteries have an expiry date because they discharge by themselves. 

How long do Duracell 9-volt batteries last?

You can keep a pack of Duracell 9V batteries for 5 years without being used. After that, you won’t get the same capacity as a new one. 


Do you know that 9V batteries are also called transistor batteries? It is an interesting fact. 

The reason is that 9V batteries were famously used in transistor radios back in the day. 

Have you got the answer to the question, how long does a 9V battery last? Now, do your research, and buy the one that meets your needs.

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