What is it?

The Dual Size 10 Hearing Aid Battery Holder is a custom module designed to securely house and connect two size 10 hearing aid batteries to provide (close to) 3V for your projects. Originally made for hearing aids, the size 10 battery offers high energy density in a very small package. Take the Rayovac R-10AE-6 ZM battery as an example: it has dimensions of just 5.8mm x 3.6mm and boasts a specification of 1.45V / 250mAh (as sourced from Digikey). When you pair two of these, you get nearly 3V, which is enough for many microcontrollers, including the ATTINY and ATMEGA series. However, not every brands of hearing aid batteries offer such high energy density. So be sure to buy ones that offer similar specs as the one above. You can purchase Size 10 batteries online from Digikey and Amazon, or offline at places like CVS and Walgreens.

I created this battery holder recognizing the underutilization of the size 10 form factor, largely due to the absence of a suitable battery holder. Every battery holder is uniquely crafted, featuring resin 3D printed casings combined with metal leads that are soldered to a PCB, ensuring a solid series connection between the two batteries. As you can see from the pictures, the module is significantly smaller than the CR2016 form factor. To ensure that the module remains compact, I designed it using castellated pins. It can be soldered directly to your own PCB board design without the fuss of dealing with big header pins. Though you CAN actually solder this to standard header pins as it is designed with the standard 100 mils (2.54 mm) pitch.

The module has just two pins:

• N: battery negative
• P: battery positive

The Size 10 battery holder can offer a range of applications, especially for the makers and DIY market. Here are some potential use cases:

Wearable Tech: Due to its compact size, the battery holder can be integrated into wearable devices like fitness trackers, or even smart jewelry.

Miniature Robots: For hobbyists building small-scale robots, the battery holder can provide a lightweight and efficient power source.

Remote Sensors: For DIY home automation or gardening projects, the battery holder can power sensors that monitor temperature, humidity, or light levels.

Smart Badges: For events or conventions, makers can design interactive badges that display names, affiliations, or even QR codes, powered by the Size 10 battery holder.

Compact Flashlights: Ideal for pocket-sized or keychain flashlights that require a small but powerful energy source.

Microcontrollers: As mentioned, the battery holder can power microprocessors like the ATTINY and ATMEGA series, making it suitable for a myriad of small-scale electronic projects.

The Size 10 battery holder's compactness and power output make it a versatile choice for a wide range of projects in the makers community.