Sunday, November 2, 2008

A Nice Little Joy Ride

So I got the plates machined on Friday! It was great, I went over there and planned on leaving it for the day, but one of the machinists was free and did it for me right on the spot. Took about 20 minutes and they didn't even charge me! I had each of the bolt each counter-sunk 1/8 inch and now the ticking sound is completely gone. There are excellent people at the R.J. Moran Machine Shop and I will be doing business with them again, I know that.

I also decided to take a pic of my control board before I get to neatening it up. I was going to work on the box this weekend, but I decided to put the motor back in and drive it around.

Now for the goods. I reinstalled the motor and control board back into the EV and I adjusted the low voltage setting on the controller and drove it. I left the controller at 75% maximum output, and man was it sluggish. It drove like an oversized golf cart and i could barely hit 10 MPH up a mild hill and I could get to 15-20 MPH with a slight down hill and a long runway of road. So here is my video of that test:

Then I had a few things to do, came back and decided to set the controller to 100%. What a difference! Not only was is much peppier, I was hitting 15 MPH easily and got up to 25 MPH before slamming on the brakes to avoid the little kiddies playing in the road. Sadly, I didn't get a video of this run. I have clocked about 2+ miles so far in my EV!!!

The performance seems rather low at the moment because of four factors.
1) I am only running at 60 volts, and the torque for my motor is rather low at this voltage. So essentially it is an oversized golf car.
2) I had sticky front brakes that need some attentions and this is definitely created more drag. 3) My PB5 throttle control doesn't go all the way because of the limited throttle cable, and the actual design of the PB5. I haven't measure how far it actually go, but I think I only get 75-85% of total throttle output.
4) the tires are really low on pressure. I mean really LOW, and this is adding unwanted rolling resistance.

So on Monday I plan on pumping up the tires and giving it another go and see if there are any performance increases.


Justin Sawell said...

My control box setup looks EXACTLY like yours, spread out on the work bench like that. Except for the controller - I'm still saving up for that.

I'm thinking of enclosing it all inside a large plastic tool box with a lockable lid and "High Voltage" stickers for neatness and safety.

You must have that EV grin all over. Great stuff so far!

David Harrington said...

I have this metal water proof box that I plan on using to house the contactors and the relays that are in that black box.

I think I am going to throw in another battery in the trunk for 72 volts, pump the tires up this afternoon, give it a fresh charge and try it again.

Justin Sawell said...

I've been tossing around the idea of a range extender like that: Having a port in the trunk where I can stick another 3 or 4 batteries if I need them, but take them out if I'm just running to work and back.

Maybe hooking up a relay so I can disconnect "dead" batteries and fire up the "live" ones - although I'd still be lugging around 200 pounds of dead weight...

David Harrington said...

I think the best thing would to be just build the EV with the highest voltage and the most batteries possible. Within reason, of course. Dead weight will probably lose you more range than you would gain. I haven't added more batteries to test yet because I haven't made any more cables. When the EV is done it will be a 96 volt system and about 520 lbs of batteries.