The battery which is used in handy electronic devices like cameras, radio transistors, alarm clocks and the like, is called AAAA battery.
It is an arid type of battery. German people call it Mignon informally, which means very delicate and attractive.
In China, it is know as #5 batteries. AAAA battery is made up of a mono electrochemical cell.
This AAAA battery is 42.5 mm in length and its diameter is 8.3 mm. the weight of this battery is around 6 to 7 grams and emits 1.5 volts power.
There are two classes AAAA batteries which are technical referred as LR8D425 (IEC) and 25A (ANSI/NEDA).
It is also sorted by its Duracell number as MN2500 or MX2500 or sort by its boosting number E96.
The size of the AAAA battery is mostly suitable to fit in the devices like LED penlight, powered computer styluses, laser pointers, headphone amplifiers and glucose meters etc, which need small batteries only.
Though the AAAA batteries are more advanced version of AA and AAA batteries, this model is not as popular among the users as its ancestors are.
So it is very difficult to find out in the market. But a standard alkaline 9 volt battery can be built with a set of Six AAAA batteries inside, attached by join tabs or small circuit panels.
Most of the parted 9 volt batteries can supply the power of AAAA batteries.
These batteries are also available in 10.5 grams weight in the version of 8.4 mm x 66 mm of PCB label.
These are NiMH rechargeable batteries and get charged from the PCB power supply to which they attached to.
These are the features in brief of an AAAA battery which is rare and not very famous but very useful in the use of portable electronic devices.