Which is the best 9V battery

10x 9V block batteries in comparison, who is better Varta, Duracell, Energizer, ...?

9V block batteries are used less and less in everyday life, but they are still used in measuring devices and smoke detectors.

But which block battery should I buy? There are hundreds of models in the trade, all of which are aimed at customers with big words. Is it perhaps worth buying more expensive models or do the cheaper block batteries do the same?

Let's find out by comparing 10x 9V block batteries!

 

10x block batteries in comparison, the test candidates

For this test / comparison I bought 10 different block batteries from Amazon with my own money.

These are the following models:

As far as prices are concerned, there are of course massive fluctuations depending on how many you buy. Big packages = cheaper. Here are the prices per piece that I paid:

There are massive differences here! While I only paid € 0.85 per battery for the simple VARTA Industrial, the expensive VARTA Lithium beats booking a whopping € 6.35 per unit. This is lithium based.

But I found it interesting to include a lithium-based 9V block battery in the comparison. All other block batteries are the typical alkaline models.

 

The 9V batteries in detail

Unfortunately, not all batteries have a production date. However, I found an expiration date on all batteries, except for the VARTA Industrial.

AmazonBasics Everyday Alkaline BatteriesJun 25
ANSMANN longlife smoke detector 9V blockApr 26
Duracell Plus Power Type 9VJan 25
Energizer Max 9VDec 25
GP Extra Alkaline 9VJan 26
VARTA industrial battery 9VX
VARTA Lithium 9V blockDec 30
VARTA Longlife Max Power 9VDec 25
Varta LongLife Power High EnergyDec 24
VARTA Power on Demand 9V blockJun 24

Most block batteries have a shelf life until 2025/2026. Only the VARTA Power on Demand should only be durable until mid-2024. However, I may have received a model from the previous year.

For the models where a production date was noted, it was always in 2020! So I don't seem to have got any really old stock items.

Let's look at the weight. It is of course not important here how heavy your fire alarm etc. is, but more mass can be an indication of greater capacity.

At 40.1g, the VARTA Lithium 9V Block is the lightest battery thanks to its lithium base. In second place among the lightest batteries is the ANSMANN longlife smoke detector 9V block with 44g. The heaviest battery is the Duracell Plus Power Type 9V with 48.3g.

 

The test

We come to the most exciting test, that of capacity. Since my regular measuring device does not hold 9V batteries, I use my power bank test setup. I discharge all batteries at 0.05A until the voltage falls below 6V. Then the test is stopped.

Why do I discharge the 9V block batteries at 0.05A? As far as I know, block batteries are not used in high-power devices and are not suitable for them, or only to a limited extent. As a rule, block batteries are used in fire alarms, multimeters, remote controls and other devices that require extremely little energy. A discharge current of 0.05A is the lowest that I can measure reliably enough here.

Unsurprisingly, the lithium block battery literally dominated the test. With a capacity of 6.906Wh, this surpasses the next best alkaline battery by more than double!

Compared to the weakest battery, the VARTA Industrial Battery 9V, the VARTA Lithium 9V Block has 3.2x capacity! The VARTA Lithium 9V block is also 6 times more expensive.

But what about outside of the lithium block?

All the alkaline block batteries are relatively close together.

  1. Energizer Max 9V
  2. AmazonBasics Everyday Alkaline Batteries
  3. Duracell Plus Power Type 9V

In itself there is only one surprise in the top 3. The fact that Energizer and Duracell are at the top shouldn't come as a surprise. Energizer and Duracell are the two largest and also pretty much the most expensive brands.

The Energizer Max 9V Block achieved a capacity of 3.085Wh and the Duracell Plus Power Type 9V 2.956Wh. However, a surprise has set between the two, the AmazonBasics.

I was so surprised by the very strong performance of AmazonBasics that I repeated the test twice. Battery 1 = 2.958Wh, battery 2 = 2.905Wh and battery 3 = 2.961Wh. So yes, the very cheap Amazon battery is right up there!

Surprising insofar as the Amazon ratings are rather mediocre. However, Amazon apparently sells partly different models under the name “AmazonBasics Everyday”, so I cannot rule out that the earlier reviews from 2017, 2018 and 2019 partly refer to other versions (with white housing).

The VARTA Industrial Battery 9V lands in last place with 2.139Wh. Not a big surprise in and of itself, this is also the cheapest battery. What is a big surprise with the VARTA Industrial battery is the wide spread! I had tested a whopping 5 block batteries with the following results: 1.98Wh, 1.99Wh, 2.139Wh, 2.222Wh and 2.68Wh. So there seems to be some variation here that I haven't seen in any other battery. In the end, I chose the middle result, as this seems to be closest to the average.

There is a difference of around 44% between the first placed and last placed 9V block battery (the lithium cell left out).

Here also the open circuit voltage of the individual block batteries, in case someone is interested. However, this did not seem to draw much conclusions about the capacity.

 

Conclusion

Let's make it short, this is the result of my test:

  1. VARTA Lithium 9V block6,906Wh
  2. Energizer Max 9V3,085Wh
  3. AmazonBasics Everyday Alkaline Batteries2,958 Wh
  4. Duracell Plus Power Type 9V2.926Wh
  5. VARTA Longlife Max Power 9V2,892Wh
  6. ANSMANN longlife smoke detector 9V block2,581Wh
  7. Varta LongLife Power High Energy2.234Wh
  8. GP Extra Alkaline 9V2.215Wh
  9. VARTA Power on Demand 9V block 2.2 Wh