There are times, especially with electronics, that you want to use AA batteries but to do so would give you and “over voltage” situation that would burnout those sensitive electronics. Well, there is a solution…dummy batteries.
Briefly, these are battery “look-a-likes” but are not actually batteries. They pass current through them but add no voltage themselves.
So the first picture below is that of a AA battery tray for a Baofeng UV-5RA radio. This battery tray is part of an aftermarket battery case that allows you to use AA batteries with the UV-5RA radio. < read more about the battery case here >
So, this looks all fine and dandy and ready to use with the radio. However, you could burnout the radio using this battery case with these six 1.5 vDC batteries in the battery case.
The UV-5RA radio is designed to work on a maximum battery voltage of about 8.5 vDC. This battery configuration would give you about 9.1 or 9.2 vDC with brand new decent-quality AA batteries.
Can you say “sizzle!”
So why was the case designed this way to begin with?
If you swap out the alkaline 1.5 vDC batteries with the standard 1.2 – 1.3 vDC rechargeable batteries then you get voltage measuring in at 7.2 – 7.9 vDC. And that is well within the operating voltage range of the radio.
But you have another option, an option that can be used with alkaline batteries pumping out 1.5 – 1.6 vDC per battery…dummy batteries that I mentioned earlier.
The dummy battery is simply a non-battery in a casing that looks like a battery. The dummy battery allows current/voltage to flow through while taking up space in the battery case and not adding another 1.5 vDC to the current. So now you can put five alkaline batteries in the battery tray along with one dummy battery and have voltage that is within operational voltage range.
Note: Carry the sixth alkaline battery with you. When the electronic device shuts off due to low voltage, swap out the UltraCell dummy battery for the good alkaline battery that you’ve been carrying. You will get a little more life out of the electronic device. Maybe just enough to make a huge difference before the fresh battery is discharged.