September 21, 2007 by Rob.

One thing I’ve noticed about the RAVolt is that there are times when pushing on the accelerator does not produce more power.  Typically this happens on hills when I really want that extra power.   I’m moving along OK, but my ammeter is pulling a low 200 and the voltage is hardly sagging.  Normally, I can put my foot down and get some extra “go.”  It’s common for me to burst over 400 amps going up a hill.

It turns out that my Curtis controller’s current limiter is on the OUTPUT side of the controller while my ammeter is on the INPUT side.  The PWM (pulse width modulation) going on inside the black box does not always translate directly back into readings on my analog gauges.

I knew that the Curtis had a current limit - I’m just surprised how it shows up.

Posted in Daily Use, Parts, EV Tech | No Comments »

September 21, 2007 by Rob.

I had a really good time showing off the RAVolt at the CleanTech grid vehicle forum.  Unfortunately, I could not stay for the panel because I would like to hear what they had to say.  Hopefully someone from the AustinEV group will post some minutes and I’ll include a link (hint).

We had a good turn out and I was happy to see many familiar faces an also make some new friends.  I’m getting comfortable explaining that the RAVolt was not designed to be a “show EV” and my goal was to get on the road quickly and cheaply practically.  I hope that makes it more approachable and I’ve stopped pretending that everyone could do (or would want to do) a project like this.

After the crowd went inside for the panel, Erik and I got to do some serious EV geek speak.  He was so full of great suggestions that I’m going to schedule an open garage to review the RAVolt and get more tuning ideas.  Some of Erik’s gems include:

• Building an “oh shit” 110 VAC recharger using a rectifier.  It would need to be monitored, but rectified 110 VAC become 150 VDC pulses.  That’s perfect for charging my 144 VDC pack!  More designs to follow.
• Adding a auxiliary battery volt meter (amen to that!)
• Upgrading the cell caps on my floodies to reduce water loss.  Between the heat and speed bumps, I’m loosing a lot of water.  The caps would also make it easier to water my couple of batteries with cables running over the cell covers.
• Looking for ground faults from the traction pack.  I’ve been getting a little “zing” when I touch some components and that’s from a very small short with the traction pack.
• Grounding the car chassis when I’m charging.  The traction pack is supposed to be isolated, but it is nice to be extra safe.  I’ve got the ground wire available, it’s just not connected.

PS: It’s great to meet people who are reading the blog!

Posted in Improvements, Storyline | No Comments »

September 21, 2007 by Rob.

Next weekend (9/28-30) is the 8th Annual Renewable Energy Roundup and Green Living Fair in Fredericksburg.  This event is heavily attended by the AustinEV group and should be really interesting.

I’m not able to the RAVolt out there, but nearly every other Austin EV is making the trip.   I’m hoping to swing out there to see the event and will post some photos if I go.

Posted in Green Tech, AustinEV | No Comments »

September 21, 2007 by Rob.

The RAVolt had a busy week with two over 25 mile days.  We made it home both days with out causing traffic congestion and I’m getting more comfortable about attempting drives near the edge of my range.  I still make a point to drive extra gently when I know that I’m in for on the long drive.  Both days covered most of the miles at highway speeds (MoPac and 360).

One downer: I’m still having trouble with my auxiliary battery.  This is not a big deal since I can just jumper the auxiliary from one of the traction batteries.  Unfortunately, I had to pull up to the CleanTech forum with the jumpers on :(  - I hopped out and popped them off, but it was a little embarrassing.  Of course, the battery has been running fine since then.

Posted in Daily Use, Storyline | No Comments »

September 21, 2007 by Rob.

This dramatic EV bike crash has been all over the EV groups, but did not make waves in the non-nerd news world.  I retold this story at least 3 times today and figured that more people would be interested.

KillaCycle is a BAD ASS hot rod electric bike that goes 0-60 MPH in under 1 second and gets up to 158 MPH in 1/4 mile.  That’s really really fast.  Unfortunately, it’s also too fast to react if you happen to gun the motor on a city street.  The first part of the video is an interview about the bike - the crash was supposed to be a demo of the bike doing a burn out.  Ultimately, both rider and bike are OK.

No worries about the RAVolt repeating  the KillaCycle performance.  I’ve installed 1200 pounds of lead as extra inertia to ensure that I don’t accelerate too quickly.   Maybe when I upgrade to lithium A123 batteries…anyone interesting is sponsoring us?

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