Testing a Multitude of Batteries

NAZAR BUDAIEV, BU PHYSICAL ELECTRONICS LAB

Nowadays we utilize dozens of replaceable batteries in our households. TV remotes, toys, flashlights all use some kind of standard battery. Thus, it is crucial to understand the charge remaining in the battery. This project provides an easy to use interface for consumers to test voltage of a battery under load. When the terminals of the battery are connected the device will light up one of the LEDs – green, yellow, or red, depending on the ability of the battey to maintain proper voltage under load. The user will be able to switch between different types of batteries:  1.5 V, 4.5 V, and 9V.

On the left hand side of the device there are two leads to attach to a battery (red wire goes to "+" on the battery, black wire goes to "-"). There is a standard connection for 9V battery present as well. When device is connected to power the display will light up and show "0.00". Now you can select one of the three types of batteries to test: 1.5 V, 4.5 V, or 9 V. In order to do so, press one of the buttons on the right hand side of the device. When a battery is connectd the device will display the voltage of the battery under load. It will also light up one of the LEDs depending on how well the battery is performing. New batteries will light up green, somewhat used ones will light up yellow, and elmost empty will light up red. If you wish to switch to a different type of battery simply press the corresponding button.

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Here you can see the device in action. Thick blue wire is connected to computer USB port. On the video I test two 9V batteries. I connected the first battery and press "9V" button. Yellow LED lights up indicating that this battery has been used for some time. Then, I connect the second battery and green LED lights up. This incicates that the battery is new.

2020 - Nazar Budaiev