Is this a forum for
ants only good ideas? I know this is very much not the way to do it. Ideally I would want a battery with a minimal full load voltage greater than the motor with an off the shelf controller.....

BUT! It seemed like a project that has lots of oppertunities for experementing with funcky control loops and high power and some cool flat wire inductors I got.
However, I have re-named the thread to something a bit more accurate (thanks for the inspiration Magic

)
Also, to address the reasons this is a terrible idea, and maybe make it sound like not-such-a-terrible-idea project......
1) Minimum voltage output
Yup. if i were running the motor directly off it... This would be bad. Buuuuuuuut I have an extra low side switch for fine speed control, right down to 0%.
2) load current regulation
I have current sensing on output and input. I can control my load through adjusting both the boost AND the motor drive FET.
2.5) This is not a fixed output converter
I have a PIC that measures the motors actual speed vs demand. If it starts to run on too low of a drive signal, it can reduce the boost output voltage. Negating a lot of the efficiency issues. this also means I can loose the boost in the future and just have a 180v supply.
3) Flogging lead acid
pB is not ideal. Would rather have Li-ion or Li-po, but on top of the cost, I want to minimise risk of bang bang when charging. If i could run this off a bench supply, at 100%, I would.... But I'm not allowed a 150A bench supply

4) treadmill motor
A few minutes of full power would make me very happy

I'm not doing laps on this thing. If it goes ka-bloom then oh well. I get to buy brushless

that does remind me though that I should put a temperature sensor on the motor.
So, with all said, I'll try and get some results up at some point

or pictures of a charred PCB stack.