Friday, January 29, 2010

Once again, we have learned that I am good at breaking things. In fact, I usually learn best when something ends up broken. That way, I know not to do it again. This time, I managed to fry the logic board in the Open ReVolt "Cougar" Controller. It all stems from hooking up a tablet computer to the controller to use for reprogramming and data-logging. I got the tablet computer for free, but it doesn't have a battery. Instead, it needs to run from 12V DC to a 12 to 20VDC converter, and into the computer. I didn't realize that the RS232 port has so much grounding in it, and I somehow managed to push over 20 volts to the ReVolt 12V in. The other night, I got to stop over at Tom's house (for Robot Night) and I pulled out the multimeter and soldering iron to figure out exactly what parts I broke. We tracked down that R1 and D2 were both smoked. R1 was easy to replace, and the controller can work fine without D2, as long as you have a known good voltage going to the controller. Further bench testing showed that the ATMEGA chip was either fried or had a bad case of amnesia. Fortunately, I had a spare one of those from when I did a software update a while back. UNfortunately, replacing the ATMEGA chip did NOT make the controller work properly again, although it does seem to prove that everything on the POWER board works fine, it's just the LOGIC board that's all messed up. The 12V DC/DC converter tested out OK, as did the doo-hickey that converts 12v to 5v. However one or two other 5v components may be bad, and I have no really good way to test them. Paul Holmes offered to help me out by mailing me some spare parts, and possibly even soldering up a fresh logic board. So, my car isn't running right now, but I sure am learning a lot by poking at electronics with multimeters! Another thing I learned about the Open ReVolt controller that I thought is kinda cool is that it's much easier to bench-test than, say, a Curtis controller. For example, a Curtis controller usually has come sort of voltage range, like 48-72V. That means you need at least 4 batteries just to power the thing up (if you, like me, do NOT have an adjustable bench power supply.) You then need 4 12V light bulbs, or a spare motor, or something similar to use as a test load. It starts to be quite a setup. On the other hand, the ReVolt only requires a 12V battery for logic power, and almost any voltage you want for the power section. The test load can be a single 12V light. All I needed for bench testing was a 12V battery and lightbulb, a few jumpers, and a pot. That's it! Even I can handle that. More next time, once I get this thing on the road again. -Ben

Monday, January 18, 2010

Tablet PC for EV Controller

Yesterday was another EV build day.

The big fun surprise was that my friend Tom had dug up a tablet PC that runs Windows XP.

That means I can run the RTD Explorer software on it to view information, in real-time, from my controller. I will also be able to tweak the settings on the controller. For example, if I want to accelerate faster, all I have to do it type in a command. I could also turn it down if someone else is driving the car for the first time (possibly good for Valet Parking!)

Since it is a full-blown computer (just only a 8.4" screen though) I can also run music or videos on it. I think the computer will be mounted right by the car stereo, so I can output sound from the PC into the car stereo.

This could be nice to be able to show off some of my YouTube videos in the car while displaying it at a carshow. The tablet PC even has an expansion port. If I can find a dock that goes with it, I could use it to run a second monitor to display in the engine compartment!

For specs on the tablet PC, please visit:
Mine does not have Bluetooth, and the antennae on the wireless LAN doesn't seem to be working right. Also, I have no battery for the computer, but was able to find a power adapter that will take 11-16V in (range of 12 battery voltage) and output the required 20 volts DC for the computer.


Friday, January 15, 2010

My Grandmother: The EV Queen

My grandmother was in town visiting this last week. While I missed the family dinner with her (as my mother picked a date out of the blue WITHOUT asking people IF they were available first) I was able to visit her by myself a few days ago. I brought some slides and photographs that I had converted for her, and that got her talking about old times. What I hadn't realized, is that my grandmother is the undisputed Queen of EV's. My grandparents lived in Wisconsin, but after retirement, started spending winters in Arizona. Where they lived, many people used golf carts to zip around the retirement community, and travel to the local grocery store and other places for other near-by needs. Since my grandfather passed away, my grandmother started living full-time in Arizona. She told me that the first time they went to Arizona - in 1986 - they bought a 36V, 1956 model electric golf cart. She didn't disclose the price, and I forgot to ask what brand it is, but both Marketeer and Cushman had both just started producing electric golf carts only a few years before that. Now here's where it gets good. In the conversation, she mentioned "It's not like golf-carts are free to run. I finally just had to replace the batteries." I asked how many times before she had done that. "Never, this is the first time I've done that since buying it." That's right. My grandmother bought a 30-year old golf cart, over 20 years ago, and has only replaced the batteries a cost of $300. They must have a senior discount down there. Last I checked, golf-cart batteries typically run over $100 each!!!! 82 years old - double hip and knee replacement - sharp as a tack - and still drives herself to the grocery store - in her 50 year old electric car. Hope I am doing as well in 50 years. -Ben

Wednesday, January 6, 2010

Enginer Prius PHEV Conversion: Part 5

After I left Tim's house on New Years Eve, he continued working on finishing off the Enginer PHEV kit in his Prius. This footage was shot by Tim as he connected the wiring from the PHEV kit to the cars computer. He has since driven the car a few times and noticed higher traction pack voltage because of the PHEV kit.
He will still need to do some more driving to find some the actual fuel economy improvement from installing the additional battery pack.

Tuesday, January 5, 2010

Chris' Electric Motorcycle First Test Drive

Sunday was another EV Build Day.

While I was busy updating the firmware on my Open Source Controller, Chris and the other guys were adding brake fluid and tach-testing the cycle.

The big excitement was to actually take the bike outside and road test it in the snow.

While the cycle did beat 1200 RPM with the back tire up in the air, an actual road test showed it to be considerably slower. The controller on the cycle is just a low-amp golf-cart controller donated by one member. It was thought to be a faulty controller, but hey, it was free!

Once we were done playing with the bike in the road, we brought it back inside for more troubleshooting. Looks like the controller is bad after all. We might just have to borrow a known good controller (like the one from my Citicar) just to see what the cycle can do at full speed.

I was amazed at how quiet the motorcycle was. The driveshaft is CONSIDERABLY quieter than a chain drive.

The cycle already had the shunt for an ammeter installed, so we will have to add the ammeter itself for further testing. Also, the cycle is running with 3 batteries in it (36V) but is designed to fit 4 batteries total.

We'll post another video of motorcycle testing after the next EV Build Day.

If you are anywhere near the Milwaukee, Wisconsin, USA area, check out:

Monday, January 4, 2010

Cougar Controller Firmware update

I just finished updating the Open Source Controller firmware and the real-time display software.

I now have a lot more ability to tweak the settings of the controller, including limiting amperage, and using the controller to close the main contactor after an adjustable pre-charge time.

It's fantastic that since this is all open source, anyone can add new features to the controller through simple software-only updates.

Essentially, almost anyone can build a 500 amp, 144V controller that would rival a $1500 one, for about $300 in parts.

To buy a kit, or find out more about this controller, please visit:

Friday, January 1, 2010

Enginer 4K Prius PHEV Conversion part 2

Second section of the installation video.

Enginer Prius Plug-in Conversion part 1

Yesterday, I got to help out my friend Tim, by lending a hand helping install the Enginer Plug-in kit in his 2004 Prius.

It took a couple hours. There were a few odd little things that were just a bit frustrating in the installation, but overall, it was pretty straight forward.

While I wasn't able to stick around to the very end, we did get the install almost all the way done.

I broke the video into the following 4 on YouTube