/diy/ - Do It Yourself

>>600461
Ohh yeah, I saw your thred a few days ago.

bretty cool.

I didn't realize you had the added step of splitting H20. That makes things a little more complicated.

The most practical thing I can think of is measuring the output current and voltage of the fuel cell over a full discharge. If you can do calculus: integrate the area under the curve [with Current*Voltage on the Y-axis and time on the X axis].
If you cant do calculous, just take the averge current times the average voltage times the time it takes to use up your stored hydrogen/oxygen.
Energy = Current*Voltage*Time

Its very difficult to measure the efficiency of a vehicle using the physics definition. Because, once you reach top speed, you're not really doing work any more.
F=m*a
W=F*d
If speed is constant a=0 so,
F=0
W=0

That's why cars are rated in miles/gallon [km/liter] and not percentages.

You can assume the motor has ~90-95% efficiency if you want to include that.
Total Efficiency = (Efficiency of Step 1)*(Efficiency of Step 2)*(Eff.... so on