For now yes... please. Poor horsie.. :p

The ply is a good idea.

But I will revive this thread once mine arrives and I do a little peek and poke.

Till then !

So could one modify this unit to be able to use a 12v battery?
Such as a small motorcycle or garden tractor battery?

Yes quite easly Woody. There is the jst connector inside which could be connected to a jumper run out of the case through a hole of some sort. Or put a jack of some sort into the bottom of the battery case cover. Observe polarity of course.

On the one I just received the positive lead for the connector is on the pin closest t to the bottom of the battery tray opposite the lid.

For the record as I understand it the jst connector is rated for 10 amps continuous and is connected with what appears to be 24 gauge wire.

Now for the diagnosis. I got her open with little trouble and found the following:

There is not much in the way of circuitry. A printed circuit board populated as follows. A very large (6A10) diode to protect against reversed polarity to the LED and buzzer. That diode is a brute rated at 6 amps at up to 1,000 volts! Then the led itself and its 1/8 watt dropping resistor. The 'switches' are just leaf spring tabs that are pressed down with the buttons. The key 'switch' is a similar matter with two leaf springs that make continuity when the 'key' metal pin is inserted between them. All wiring inside the unit is 24 gauge. The NEC does not give ampacity for 24 ga wire but I believe in these short lengths it is capable of 10 amps.

I tested the current with a really cheap harbor freight multimeter but measured 40ma with the led on and 60ma with the buzzer activated. No way to measure the peak current but with a 3S 1800ma lipo at a 'storage' charge (3.8V/cell or 11.36v total) it incinerates estes starters and Quest Q2's go off with a resounding snap :D

That pretty much sums it up except for the JST connector is glue welded into the case. I was hoping to replace it with something a little more robust but when its all said and done it is probably adequate for the average task of low to mid power rockets.

Sounds like the controller should serve its intended use very well. Should you really feel the need to replace the JST connector, don't underestimate the capability of Mr. Dremel with his cutting wheels and grinding stones!