Ran a couple of additional tests for my cut down circuit and I have decided to change the batteries.

Initially I was trailing two banks of 4 x AA’s in parallel giving about 6 volts. This seemed to be enough to heat the wire. However I hoped for a better solution.

Firstly I would have needed 8 fresh batteries which adds extra weight, and I still wasn’t getting the wire glowing red.

So tonight after stupidly dropping the AA battery holder and cracking the case, I decided to run a test with a couple of 9 Volt Batteries and wow, so glad I did.9vbattery

With two 9 volt batteries in parallel the wire glows bright red and cut through my test twine like butter.  So I think I’m moving in the right direction,

I should probably also run a test with a single 9v to see if I get a similar result. Happy for anyone to offer other suggestions for a cheap simple battery source to get that Nichrome wire red hot.

So far the cutdown system is partly fixed to a PCB

So far I’m happy with the circuit. The relay is soldered in place, and I still need affix a few of the other components but its looking good. Relay also seems to hold up to the current.

Thinking about getting the lithium version, as it may be better for the cold temperature.