Short Circuit Protection circuit design help

Planning on making a power pack consisting of 4 1.2V or 1.5V AA batteries in parallel. I am now trying to create the same type of circuit as the one pictured, or something simpler and better, but to be compatible with AA batteries. Are there components available to make this happen? Ive been researching online and couldnt find any such designs for my specific application at the 1.2-1.5V range. I am not an expert at all with electronics so I have no idea what Im doing. Suggestions for a new, better design, or anything like that would be highly appreciated.


If one fixed the incorrect symbol for Q1, that’d be an on/off circuit with zero protective effect against short circuits. It also won’t do what it’s supposed to with a 1.5v source.

If you’re after on/off function, a plain 'ol switch of some kind would be your best bet. If it’s short circuit protection you want, ask yourself whether it’s really needed; the internal resistance of typical dry cells doesn’t generally allow for enough fault current to be a serious issue. If you want it anyhow, I’d suggest a plain old fuse.

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Thank you so much for the input! This power pack will be for image intensifiers so it is quite sensitive equipment nontheless. The battery pack is planned to be waterproof since exposure to water would be common for this application, this is why I was after a short circuit protection system of some sort. A fuse was on my mind but I wanted something “reusable” that I can turn back on once the fault is fixed.

Is there anything else you could recommend besides just a fuse? If I could make something work in a similar manner as this Id be quite happy if it would be possible.

It’s generally consider bad practice to connect primary cells in parallel. The internal resistance varies considerably between individual parts leading to many problems but mostly shorter battery life and overheating.

If you do connect them in parallel, you should make sure all batteries come from the same manufacturing lot to lessen the problems from different internal resistances.

The best solution to get more mAh is to use a single larger primary cell such as a “C” or a “D” cell.

Some references:


Hi pelcalex1,
Regarding reusable fuse, you may want to look at PTC Resettable Fuses or an Electronic Fuse. Please review specifications inside each datasheet as this is a generic link.

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Exactly what I was looking for, I never knew these even existed. I will look through the options. Thank you for those links!

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