Remember Duracell’s PowerCheck? The idea was that a strip built into the battery would show if the battery was good or not. Sure, you could always get a meter or a dedicated battery tester — but PowerCheck put the tester right in the battery. [Technology Connections] has an interesting video on how these worked and why you don’t see them today. You can see it below.
Duracell didn’t invent the technology. The patent belonged to Kodak, and there were some patent issues, too, but the ones on the Duracell batteries used the Kodak system. In practice, you pushed two dots on the battery, and you could see a color strip that showed how much capacity the battery had left. It did this by measuring the voltage and assuming that the cell’s voltage would track its health. It also assumed — as is clearly printed on the battery — that you were testing at 70 degrees F.
The temperature was important because the secret to the PowerCheck is a liquid crystal that turns color as it gets hot. When you press the dots, the label connects a little resistor, causing the crystals to get warm. The video shows the label taken apart so you can see what’s inside of it. The resistor isn’t linear so that’s how it changes only part of the bar to change color when the battery is weak but not dead.
It is a genius design that is simple enough to print on a label for an extremely low cost and has virtually no components. PowerCheck vanished from batteries almost as suddenly as it appeared. Some of it was due to patent disputes. But the video purports that normal people don’t really test batteries.
Watch out for old batteries in gear. Of course, if you want to really test batteries, you are going to need more equipment.
I probably still have one of these testers at home. I peeled it off the battery and attached 2 wires to it with a small screw and nut. I used it as a universal AA battery tester :D
We have yet to see 7-segment displays made from batteries, or a “battery” clock made of multiple ones. Chances are we never will.
Just drop the battery on its tail on a hard surface, if its flat it bounces, if its full it goes thud. Alkaline only.
I love my 1.5 V AA-USB-C-loadable cells. They have a light that blinks blue/green/red, depending of what cell the chinesium seller has.
Just saying.
Loved the concept. It never came to my country, is there any way I can get this battery?
I still keep some from 9V (6F22) packages- they were not on battery due to size, so it was easy to peel them off the cardboard. :) That build was a bit different, as it had three crystal zones in parallel with different width.
I wish this was available for NiMH AA.
I never liked to use the built in tester.
It was clear that they worked by heating the strip. Heating the strip would require a fair amount of current, so testing your battery would also discharge the battery.
I never saw much point in running my batteries down to see if they were run down.