EVT America Z-20a

[scott.taylor]

Well, I rode the scooter to work both Thursday and Friday.  Morning temperature was 34 on Thursday and 28 on Friday.  Evening temps were about 52 both days.  After the 10 mile round trip, the power meter was reading between 1/2 and 3/4 or about 35% depleted.

Both days I was able to fully recharge the cycle with my stored solar power.  I had added two additional 105 amp-hr batteries to my primary pack for a total of 4.  This has reduced the current drain per battery and improved the efficiency (charger draws a peak 45 amps while recharging).

I also have a two battery secondary pack that I have been using to run my computer and television.  This gives me almost 600 amp-hours of total backup storage.  I have a SunSaver Duo solar charge controller which can keep the two separate battery packs charged and diaplays all the data I need to help fine tune my setup.

I measured the amount of power to recharge the scooter on Friday at 1050 watt-hrs.  This is 87.5 amp-hrs assuming a 12v average voltage.  But I collected 96 amp-hrs from the sun on Friday despite being partly cloudy a good part of the day!!  So, I have proved that, for my 10 mile round trip anyway, I can power my scooter by the sun!! :-D

So, now I just need to address my undersized wiring from the panels and wait for the sun to get a bit higher in the sky, and I am confident I can acheive my estimated 150 amp-hrs per day or more.

WOOHOO!!

Scott...

[rich.rezny]

Your scooter adventure would interest a large audience! You need to compile data from both your driving the scooter and power used as well as your solar system data and submit an article to the "Homepower" magazine.  They are always looking for submissions and it would be cool to see some FVEAA gathering pictures with your ride as the center piece!!! 

[scott.taylor]

Thanks for the suggestion, it sounds like a good idea.  Perhaps the chapter might be interested in a presentation, as well.

I have been collecting data and it will be interesting to see where performance peaks out.  The warm weather has definitely improved the range.  I just put 8 miles on it a little while ago.  Put the charger on when I got home, but it still considered the batteries full and went right to trickle.  I haven't taken it over about 18 miles so far.  When the weather is warm and I'm not pushing the limit on the speed (40-45 mph), I'm approaching 1/2 on the power meter at 18 miles [but I believe the second half will go faster ].  So far, average power use is about 114 watt-hours/mile.

I also added some more copper to the run from the solar panels to the charge controller, today.  It is about 65 feet and I was using 12 gauge wire.  Since the panels can put out 25 amps, I suspect I was losing a significant amount of power, but will need some numbers to prove it.  I have put another 10 gauge wire in parallel.  I'm probably still undersized, but getting closer.

So far, I've ridden about 130 miles all totally powered by the sun!!

Thanks for the interest.

Scott...

[eddie.roman]

Definitely keep us updated.  really cool!

[scott.taylor]

It has been a while since I posted anything, so I thought I'd pass along an update.

In short, the solar output is up, but the scooter is down!

So far I have put about 330 miles on the scooter and it has been great transportation.  There have been a few issues with quality that I'm sure they will address with later releases.  But one thing that seems to be happening to almost all of the first production scooters, is failure of the motor controllers.  EVT is being very good about sending out "improved" replacements controllers, but I haven't gotten mine yet.

On the "bright" side, my solar panels are performing better than expected.  The maximum power output of each panel is supposed to be 4.9 amps, but I have peaked out at about 26 amps from 5 panels connected in parallel.  I originally had the panels mounted on my north fence facing south at a 45 degree angle.  But once the leaves came out and the sun moved up, the panels were in the shade most of the day.

I moved them to my deck and now have them facing directly up.  So they are now in the sun almost all day.  In addition, because the panels are facing up, I am still getting direct sunlight even when the sun is on the north side of due east or west.

I have exceeded 120 amp-hours per day and could probably get close to 150 amp-hours on a good day, but unfortunately, I am not actually using that much power every day, so the excess gets wasted.  I may throw another battery or two in the primary bank to bring it up to 525 or 630 amp-hours of capacity to improve efficiency, and I need to start putting some solar outlets around the house to make better use of the excess (I currently run 1 TV and my PC and some lighting from the batteries.  This is a solar powered message!)

I'm am always open to suggestions and would be happy to answer any questions.

Scott...

[rich.rezny]

A solar canopy for your deck-shade for you with power production. Sharp makes 2 sided solar panels that get about 30% more power than one sided panels and still let light to pass thru to the other side.  BTW the huge energy show is this weekend up in Custer, WI.. www.the-mrea.org