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Discussion Starter · #1 ·
2010-12-03

A little disappointed today. I attempted the 20 mile barrier with the EV and almost didn’t make it back. Now it is cold 38-40 F. and windy I went 10 miles out and beat a 30-60 mile head wind on the return leg ( at 50mi/hr on a state highway), when I noticed a significant drop in voltage ( from 100-110) to 85-90 volts and had no more acceleration power. The last 5 miles to home was up some small hills where I could further appreciate decreasing current as lower voltage and no more than 300 amps, about 1 mile from home, up a small hill, I was slowing down loosing the remaining power I had, and I stopped at a pull of and shut her down. Luckily my wife was at home and I called her and had her bring the other truck and a tow cable. When she arrived I decided to have her just drive in front of me while I attempted to finish the last leg home up a small hill, about 10 minutes had elapsed. So I followed her up the last small hill back to the ranch, the EV now seemed to have all of it’s original power and I drove it home on it’s own power with plenty of acceleration @100+ voltage and plenty of amps. I immediately read all cells ( #20-6volt) and they read between 6.04- 6.08 with the majority @ 6.06, after 1 hour Eq. the pack read 121.3 volts. I don’t quite know how to interpret these values. But I was really hoping for a 30 mile range so that I could use the truck for a work vehicle ( I have a 28 mile commute to work with a charging station available there). The variables that I’m considering are #1 these are new batteries, and this is their 3rd cycle hopefully they will “ break in” a little bit, #2 it is cold and according to the chart (http://www.batteryfaq.org/ ) I was just under 50% SOC hopefully, when it is warmer these cells will give it up better, #3 I’ll have to try this again when I’m not driving against a hurricane. I may also try removing the air induction coil that I put on the motor ( go to EVamarica for this article) after the runs I’ve done this is the only thing, other than the motor, that gets a little warm with a hard run, my coil is 15ft of 1-0 copper between the windings. All connections and battery terminals have remained cool to the touch, I don’t think I have a connection issue. If anyone out there has any suggestions I’m all ears.
 

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batteries are chemical factories. setting for a while provides the chemicals a chance to re-align, and move the byproducts away from whatever material is used for the energy collection. Also you'll lose perhaps 30% or more storage when it is below say 70 degrees out.

What purpose is the coil? probably a bunch of voltage drop if it isn't required by the controller. might want to check that under motor running load. use a cheap voltmeter across it.
 

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Same here. Mine came to a halt on me in cold weather and I had to sit on the side of the road for like 5 minutes or so and I could drive another 1/4mile or so I'm guessing. Several repeats of this and I made it to my shop.

My boxes are insulated on the sides and bottom but not very good. At that time the tops were open. I since cut out a section of bubble wrap and placed in on top of my pack. It helps keep them warmer than it did.

And they do take a few cycles to get broken in. I think US Battery specs on mine were about 25 cycles.
 
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