minor update

minor update here, just some small stuff.

I've got the EVDisplay up and running, it's sweet!  I am using the wireless bluetooth to android version sold by emotorwerks.com.  I posted some pictures of the current sensor and the bluetooth sender box in an earlier post, this is what it looks like on my DroidX on the dash of the car.

and a closeup of the display.

it is very customizable.  I have it set up with a big analog battery current gauge, a small analog 'fuel' gauge, and then have digital readouts for voltage, Ah remaining, Wh/mi, and battery current (redundant, but the digital gauge lets me see small changes in charging voltage).  Obviously on a larger tablet you could display more info, but this is perfect for what I want!

The EVDisplay is basically the electric car version of a gas gauge.  It counts every amp that goes through the battery loop and keeps track of how much has been used.  In my case, I have 130 Amp-hour batteries, so theoretically I can use 130Ah, but you really don't want to draw down below about 80%.  Since it is also measuring the voltage of the main pack, it can calculate Watt-hours/mile, which is an EV version of fuel mileage.  I have it configured so that a full charge shows 100 Ah avaliable (about all I want to use from my batteries) so zero Ah left is actually ~80% depth of discharge.  Nice and easy to use, since the Ah remaining shown on the screen is a direct percentage (ie: in that photo it shows I have 77.5Ah remaining, which means I have 77.5% of my range left before hitting 80% dod.

a nice thing about having an amp-hour counter is that you can do partial charges and still have an accurate knowledge of how much range you have left in the pack.  With the Lithium batteries, you cannot just use voltage like you can with lead acid batteries, since all the power is in such a small range of voltage (pretty much between 3.2 and 3.4v per cell)

It's also super cool that the Bluetooth range is enough that I can have my phone in the house plugged into the wall and it still gets the signal so I can monitor the state of charge when charging from the kitchen!  Just handy for those times when I want to do a partial charge during the day.

In that first picture above, you can see a box with three toggle switches in it just above the radio (the box is currently wedged in place with a paper towel, I'll pick up some foam tape to mount it soon...).  Only one of those is hooked up right now, it's my 'stealth mode' switch, it kills the relay that runs the motor fan and my brake vacuum pump so I can move about silently in parking lots. :D

The vacuum pump has also been moved, it now lives down on the old front battery rack with the motor blower, mounted onto a cutting board (for now) that is mounted to the rack with radiator mounts (rubber isolation mounts with bolts on each side) to reduce vibrations transmitted to the car.  While doing this, I also eliminated the vacuum reservoir chamber, I found it's not really needed.  The only change is that the pump now cycles on every 1-2 braking 'events', instead of the every 2-3 that it did with the big PVC tank.

here it is looking forward, you can see the little 'muffler' on the exhaust side of the vacuum pump, I don't really think it does much muffling though... and the big K&N filter on the motor blower.

this photo shows the routing of the hose from the pump to the master cylinder.  And also just a general underhood view of how it looks these days.

The final thing I've done is to get my tachometer working!  However, it's not accurate...  My speed sensor on the motor sends a 4 pulse per revolution signal to my controller, but the factory tach requires a 6 pulse signal, so it reads low.  No big deal, I just know that my redline of 5000 rpm is 3500 on the tach.  I may make a custom overlay at some point, but that would require a lot more disassembly to get to the actual gauge face.

It turned out to be real easy to do, I tapped into the sensor signal to the controller, and hooked it up to the old ammeter wire (which I'm no longer using) which already runs through the firewall up to the back of the dashboard.  All I had to do was remove the upper dash pad, two bolts and a few clips (which broke, of course...).  Found the wire leading to the tach, snipped it, and connected it to the signal.  Done!  it's the white wire zip tied to the harness below.  While I was in there, I cut the wire going to the 'service engine soon' light, which has always been on.  Since there's no more engine to service, I figure I don't need that any more. :D

here's a shot of the tach working, and the comparison with the actual motor speed on my laptop reading direct from the controller.

That's it for now, lots more little stuff on the way, and hopefully a big rebuild of the motor mounts soon.