Battery Interrupter - Flexible PCB

Based on an idea/design by @dgrover in another thread, @MMC_Milad got a set of battery interrupters based on a flexible PCB manufactured and ready for some testing.

Flexible_PCB Battery Interrupter
L. Milad’s shorter version, R. Dale’s original design

The idea here is these may be a more robust version of the battery interrupters made using cardboard / copper foil tape for adapting simple battery operated toys.

While fairly pricey for small quantities, these could be quite cost effective at medium quantities (e.g. ~$4 for 50 + switch jack)

If you have any suggestions or comments, feel free to chime in below. Stay tuned for testing results.


Here are pictures of assembled Flex Battery Interrupter:

Thanks to @MMC_Derrick for assembly and initial testing.

@dgrover, here isthe assembled battery interrupter.


Maybe a dab of (black) silicone rubber at the back of the jack and on the flex circuit would help with the stress at the solder joints.


@MMC_Derrick, how did the battery interrupters perform in initial testing?

Dale showed me the samples yesterday, and I was impressed.

The flexible PCB battery interrupters work very well overall. They’re notably thinner and tougher than the ones often made by hand from copper tape. Also, they have cutting outlines, so you can trim them to fit the type of battery cell you’re using. This means they’re far less likely to fail, by sliding out of position. There are some caveats though, that all battery interruptors have, including our MMC ones. First, the switch and cable you use, must able to handle the full rated current drawn by the device. This is important to know, because some assistive switches were intended more for signalling PC’s than for powering devices. A switch unable to handle the required current could overheat and burn out. Also, due to the thinner construction, battery interrupters are likely be more fragile than regular wires, so they should be covered, reinforced, and protected where possible. Finally, the longer wires and cables in a battery interrupter can potentially introduce electrical noise, which could adversely affect some sensitive circuits, such as radio and wireless systems. Check for proper operation (not just power up) in these systems if you add an interrupter.


@MMC_Derrick thank you for all of the information.

@MMC_Derrick Would it be possible to get the design files, thicknesses of plastic and copper, and the name of the place you ordered the prototypes from? I am interested in having these made up in quantity so we can distribute the battery interrupters at cost. We are happy to provide credit to MMC.

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All files and info are here:

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@brentcourson, All the information about the thickness and other information can be found in the link that @MMC_Jake provided. Let me know if you have more questions. The gerber files should work with most fabrication companies but our last order was from PCBWay.

Thanks @MMC_Milad and @MMC_Jake