Tuesday, July 21, 2009

Going Over the Data

I have been pouring over all the data I have collected, such as range estimations, AMP draw at different speeds, top speed and all these hills. I them made a conclusion and took it to the electric vehicle teacher and he agreed: my controller is way underpowered.

Actually, I learned that my K99-4007 was actually quite fine for the Civic with the blower cooler and proper gear selection. It was my controller limiting the acceleration and AMP draw to the motor. Which makes sense because my controller couldn't provide the continuous power required to maintain hills, and I only need to higher AMPS for a few seconds.

So now I know it's the controller, it's on the top of my EV list of things to buy. I am still working on getting a plug at school, but I really need the upgrade controller before driving it there. I hope to have the new controller by the end of August, before the semester starts up again.


Margus said...

Let me guess: now when you manage to pull more amps from your pack, it will age a lot more quickly since you are using the marine 12v deep cycle batteries that are designed for lower current...;)

David Harrington said...

The batteries don't seem to mind the higher current. The problem is actually motor current isn't enough, and it's always higher that battery current. It's a little complicated, but there can be 700 AMPs at the motor and only 100 AMPs from the batteries, depending on the PWM duty cycle.

The batteries also have never run dead yet. The farthest I have driven them is 55 % DoD and that was after 14.3 miles of hilly driving. There are over 400 miles on the battery pack and it's driven 14+ miles twice a day and the batteries seem stronger. With better EV driving, the batteries are only driven to 50% DoD, perfect for good marine battery life. That, and this is the sacrificial pack since every one ends up killing their first pack eventually.