Sleeves and spacers reliably allow you to use AA or AAA batteries with C or D gadgets.

A AA rechargeable battery, center, can take the place of D cells or C cells by slipping into sleeves (D size at left; C size, right) designed to hold the AA battery in place.

Maglite’s used(?) to be the king of flashlights, but replacing those pesky D-cell batteries is kind of ridiculous in this day and age. So [Travis] decided to upgrade it to make use of the ever ...

The GoPro battery adapter is apparently the very first to support the powerful 18650 cell format and is capable of adding an additional three hours of HD recording per cell and are contained in a ...

You can buy battery adapters that turn AAA batteries into AAs, or even D cells. Shi says these are better than aluminum foil as they facilitate more stable physical contact.

Editor's Note: Due to the comments at the end of this article, the author has agreed to change the circuit slightly to reflect three AA batteries in series (which agrees with the photo of the ...

Replace one of the device’s AA batteries with this adapter, which takes a smaller AAA battery, and you can then switch it on and off from an app on your iPhone.

Tetherell is an adapter that lets you control any AA battery-powered device with your smartphone.

Can you start your car with D-cell batteries? And how many would it take? Rhett Allain takes the math for a spin.