Tuesday, October 20, 2009

The Metro at 108 Volts!

The one thing limiting my upgrade to a higher than 72V system has been the charger. Specifically a little tiny resistor to change the output voltage of the charger.

At the last EV Build Day, I picked up a couple resistors, which rigged in series to each other, should get me the right resistance for the charger.
(Since then a friend of mine has also put in an order to a large electronics dealer, and I got in on his order for a set of resistors for the charger.)

This morning, I was able to upgrade the resistor, and I added three more batteries to the back of the car.

Of course, this takes up my trunk space, and I did love how "Normal" the car looked with just the rear battery box.

Now at 108V, my 0-100V analog voltmeter is pretty much useless.

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I took the car out to run an errand, and test its performance.
I went up the BIG hill in my area, and the car seemed to zip right up it. Overall speed performance didn't seem like it was that much greater.

Coming back home, I was surprised that I couldn't get the car over 55 mph. It took me a while to figure out that it was because I was only in third gear! I needed to upshift to increase amps and speed. After that, I got the car just past 60, but by that time my pack was really getting run down and I had to get off the freeway.

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A while back, I upgraded the rear springs of the car to some off the front of a Ford Ranger. These springs were really designed for holding 144V of batteries, which I HAVEN'T been running since then, so the back of the car has been riding high.

With three more batteries in back, the height of the back of the car seems to level out.

I am also trying to figure out the best way to keep my batteries warm this winter. Since I only have one traction battery under the hood right now, I might move it to the back of the car, just so all the batteries stay the same temperature. This would also drop the back of the car just enough to level it out.

The car is now charging in my driveway, but I am sure I will have to top off a few of the batteries with an individual charger to get them all even.

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