From 156V to 144V

My new controller will be a 144V 500 amp, Open Revolt controller.  My battery pack was 156V, then I killed two of them (overcharge incident, see previous post) and it just seemed to make sense to take out two more and go with 144V since I'm saving a boatload of money on the controller.

Rather than just rewiring the existing set up and skipping over two more batteries, I decided to actually remove three of the batteries.  This meant I had to bust open three of the packs.  The screws that hold the straps are hard to get off and I found that using a grinder made it a whole lot easier.  Besides, unless you have the right compression tools, trying to put these straps back on are a pain in the butt!  After the straps were off I was able to step a 6 pack down to a 4 pack and a 5 pack down to a 4 pack and replace a battery in a 5 pack.  I used Gorilla duct tape to bind then together with the end plates and then placed those packs in the middle of each bank.  Last, I bound each bank together with a cargo tie.  This created some neat, organized looking blocks.

Instead of busting open a fourth pack, a 6 pack, I found it easier to tape off one battery and just add it to the pack in the rear.  So, I ended up with 15 in front (3X5) and 29 in back (6X4+1X6 (-1)).  Wow, that's looks like a complicated math formula.

Anytime I get into tearing apart a battery bank, I always let my wife know so she can check on me.  I use tools that are wrapped in electrical tape, remove any metal on my body, wear gloves and always think about where both hands are placed.  I take my time and double check the polarity of any connection.  Sparks are bad and there shouldn't be any at all.

Open Revolt Ordered/Pre-charger Wired

OPEN REVOLT CONTROLLER
I went ahead and sent some money to the guy who is going to build a controller for me.  (You can see his ad on EV Trading Post) There's plenty of stuff on Youtube about the Open Revolt controller and there's also 30 EV owners that are using them as listed on EV Album.  The primary idea was to create an open source way for people to either build a controller themselves or have one built for them.  As I mentioned in the last blog, controllers aren't cheap.  A person with good soldering skills can build an Open Revolt for about $350.  I'm having one built for $700.  That's still about $900 cheaper than a commercial off the self comparable item.  The only draw back is having to wait for a week and a half until it is built.  I am missing prime EV driving time!

PRE-CHARGER
There is a pre-charger requirement for this controller. Look at this:

 http://www.diyelectriccar.com/forums/showthread.php?t=25419

A well written article on how and why to pre-charge.  After reading that, I went outside to the shop and wired my contactor to a separate switch instead of coming on automatically with the 12V switch.  I then wired a high voltage relay to act as a pre-charger.

 
Since I won't need heat anytime soon I used the heater relay. (Guess I'll need to order another one from MINIBMS) I put one of my extra LED resistors in the high voltage line going to the controller.

The start sequence will be like this --
turn on the 12V switch,
then turn on the pre-charger.
Now wait for the controller supercaps to match the battery pack voltage,
hit the contactor switch,
now turn off the pre-charger and you're ready to drive.

And of course, while I was doing all this I tested my contactor and it too was fried from the controller melt down that happened yesterday. So.... I dragged out the old Curtis Albright that I had sitting around and it still works just fine.  I like it when Plan B works.

Blown Controller - ARGH!!

This was the completion of my first week of commuting to and from work.  Over 50 miles round trip each day completed and I was anticipating writing this blog entry as I was driving home when BANG!!! Something in the back sounded like a gunshot and the car died.  I pulled over and got out to see what had happened.  I immediately noticed the 250 amp circuit breaker was popped and thought maybe I exceeded 250 coming up the hill.  (But why would it make the big noise?) I flipped the switch, got back in the car and turned everything on and got the "bat outta hell" broken controller syndrome. That's where the motor goes from 0 to 4K rpms in like no time flat.  I quickly hit the two BIG RED disconnects and turned off the 12v power.  Got out of the car again and took a look only to see....

Look at all that black soot!  And the smell of something electrical having shorted.  Yeah, this baby is dead as a doornail.  Toasted to a crackly crunch.

It's not my fault!!! Really, most Kilovacs have managed to get fried one way or another, the manufacturer renamed themselves to Altrax and now they only do low voltage controllers. This one was rebuilt probably four years ago so I expected it to last forever.  Looks like that didn't happen. So what's out there to buy?

Replacing a controller is easy.  Having to dish out the loot for one is "not so much" easy.  There are some great "kick ass" ones for thousands of dollars and there are some crappy ones for over a thousand bucks. There's also this Open Revolt 144V 500 amp controller that a guy makes for you at $700 bucks but you have to wait a couple weeks. I would have to eliminate a couple batteries from my pack to slim down to 144V nominal. Hmmmmmm, let me think over night about this and I'll have to talk with my wifey too.  : )

GT I Electric?/Balancing Act

GT I Electric?
No kidding, the Bradley Company actually made one GT I all electric car.  I saw it on the Bradley GT site. See this thread
http://bradleygt.proboards.com/index.cgi?board=general&action=display&thread=1166

Balancing Act

The Bradley isn't balanced right as far as equal weight distribution.  Some folks have placed their 12V battery in the front of the car to help even out the load. One would think that the added weight of my lithium batteries in the front would overcompensate for the missing gas tank. But I noticed how the front tires seemed to not get the same traction as the back and on gravel, coming around a curve, it felt like I could lose traction all together.

I tried what others have done and added a dead 12V battery to the front.  At 38lbs, it seems to work quite well.  Notice I placed it on the chassis and not the battery box.  It doesn't interfere with the steering stabilizer.

Later, I decided to remove this battery as I didn't have a way to completely secure it and it got in the way of the steering stabilizer.

Happy Mother's Day!

Stop what you're doing and at least call your Mother.  Let's call it some sound advice not only from a blogger but elsewhere that's good for the soul.

My Mother-in-Law got to see my Bradley today and it is 100% Mother-in-Law approved.  She told me stories of a 1947 Willey's Jeep that they had restored and how it had been passed down from father to son to brother to grandson,used in parades, etc...

I hope my car will last that long.  30 years old so far, not counting the life of the 67 chassis underneath.  To celebrate I took it for a 24 mile drive doing 50+ the whole way; used 6.56 KWh.

 It's ready to drive to work tomorrow.

10 Hole Rotor/Gravity Bleed

I believe one of the consequences of having the wheel come off my car when I forgot to tighten the lug nuts is two of the lug nuts became stripped.  Can the rotor be tapped?  Not according to the VW mechanic I called.  "Buy a new one and don't drive your car until it's replaced."

Alright!  Now where's that receipt where I bought my rear disc conversion kit from??? Oh well, I decided to call one of the online parts companies that I had done some business with and well, to make a long story short, after the wrong one was sent and returned what they sent was a rotor with 10 holes.  What the heck?  That's exactly what the guy at O'Reilly's said when I showed it to him.  Let me back up, this rotor didn't fit the lug nuts I had but instead the second set of holes matched the rims but used smaller lugs.  That's when I took it to O'Reilly's and that's when they said...What the heck is that?

The good news is they hooked me up with the right nuts and now I'm back on the road.

Before I hit the road I did what's known as a gravity bleed.  You jack up the back of the car as high as you can and then drop the front as low as you can.  You then open the lid on the master cylinder and open the rear bleeder valves.  The theory is any air bubbles will  make their way to the rears.  You need to give this a couple hours and expect some leakage from the back.  Then tighten the bleeder valves and bleed the brakes you normally would.  I saw where Corvettes do this and it is encouraged for old VW owners to do the same.  This helped my brakes but they are still not completely perfect yet.  I'll probably have to perform a master cylinder bench bleed at some point.

Here are the results from this weekend's drives
(I measure the amount of energy going back into the pack from the charger through a kilowatt device)

Yesterday: 21 miles - 5.23 KWh used - 250wh per mile - avg speed 35 mph

Today: 26 miles - 8.46 KWh used - 325wh per mile - avg speed 45+ mph (steep hills)

So far, I've done about 140 miles in testing, still haven't gone on the 70 mph freeway yet.  But I'm looking forward to the first commute sometime this week.