Why is there no capacity value on disposable batteries?

We will see that most batteries are marked with capacity information, usually in milliampere hours (mAh), which is a common way to compare battery performance. Almost all batteries have this mark, but disposable batteries, especially LR6 AA batteries, some special batteries or aaa batteries for medical devices, often do not have such capacity labels. So why is this the case? Do battery manufacturers hide this information intentionally?

As of 2025, there is no legal requirement for disposable batteries to be labeled with a mAh capacity. Although legislation is being gradually introduced and there may be more specific requirements in the future to enforce the performance parameters of disposable batteries, we still do not know what form it will take. Regarding the labeling of disposable batteries, the maximum capacity (mAh) may not be the only factor to be concerned about. We will explain this in detail below.

The relevant international IEC/PN-EN standards specify the capacity measurement procedures for primary batteries as well as secondary batteries (rechargeable batteries). However, there is currently no unified specification to standardize the capacity measurement and expression methods of disposable batteries to facilitate mutual comparison.

The problem is that the capacity results obtained vary depending on the target application. Batteries are tested according to different procedures as needed, and even the same batch of batteries will get different capacity results each time. For example, we have conducted capacity comparison tests on 9V batteries (including hydrogen, NiMH and lithium batteries). The test results show that even for batteries of the same capacity, the capacity difference can exceed 50%, which is mainly caused by different test conditions, load types and other factors.

CENELEC (European Committee for Electrotechnical Standardization) clearly stated that the existing test procedures and standards cannot provide a universal capacity measurement method for all disposable batteries. There are too many indicators that affect battery performance, including current consumption, age, temperature, usage habits, etc. The differences in these factors make it very complicated to indicate a fixed capacity value for disposable batteries, and may mislead consumers.

IEC Technical Committee 35 also points out that numbers (such as nominal capacity) do not accurately describe how a battery will perform under different usage scenarios.

As mentioned above, most manufacturers do not clearly provide capacity values for primary batteries. The capacity marking does not usually appear directly on such batteries and their packaging. The nominal capacity will vary greatly depending on the test procedure used, so there is no comparison value and no real information about the performance of a specific battery for the end user in a specific application.

Even if we are sure that the two capacity values are measured in the same way and can be compared to each other, the mAh unit still does not perfectly reflect the performance of a primary battery.

More detailed testing shows that despite the same measured capacity value, one of the sample cells is significantly better and more powerful (it delivers significantly higher voltage and more energy), and in many applications it operates more reliably and has a longer service life. Unfortunately, this conclusion cannot be drawn by comparing only one mAh capacity value.

In summary, a single capacity value does not provide enough information to determine whether a particular disposable battery is better than another.

This applies to almost all disposable batteries, AA LR6 alkaline batteries, LR03 AAA alkaline batteries, as well as LR44 button cell batteries, CR2032 3V Button battery, etc.