OK, I'm just wrapping up some final bits and pieces on this car, but it is looking GREAT.
* Wiring in the rear pack temperature sensor -- the front's went in the other day, because
I needed to close up that battery box to get the controller in place for the test drive.
I don't have charge voltage temperature compensation programmed into the charger yet,
because I don't have any information on exactly what the compensation should be. Not a
big deal now because charging the batteries in my cool garage showed little or no
temperature increase, but I want to have that set up before the weather warms up next year
-- at the very least, a derating of voltage and current when the battery temperature goes
above some threshold, just in case operating the car in hot weather causes some battery
* Hooking up the fuel-fired heater -- When I put the NiCD batteries in this car back in
2001-2002, the new battery box forced the controller to be mounted differently than
before, and there was no longer any room to fit the gallon-sized kerosene tank in the
engine compartment, so I simply left the heater disconnected and have relied on the
electric heat since then. I decided to get that all back up and running, so I refilled
the coolant, reconnected the hoses and old fuel tank and did a test-run of the heater a
couple of days ago -- after about 10 seconds, the little heater unit fired right up. The
fuel tank still won't fit, so I went to the US Plastic Corp website and found a 2-quart
one that will -- Should have that by the end of this week and will get it installed when
* Trunk blocking and trim -- Once the rear temperature sensor is installed and that
battery box is bolted shut, I'll adjust the foam blocks around the new charger and get the
carpeting back in there.
* Take the car in tomorrow for a lube job, gearbox oil change and to check on a little
periodic rubbing sound coming from the front. I believe the sound is a brake needing
adjustment -- the sound varies with wheel speed, and if I press the brake pedal slightly,
the sound goes away.
On Sunday, when the car had been sitting overnight, I went in and measured the battery
voltages, which were all within 0.02 volts of each other -- excellent.
This morning I took a 14-mile drive at 45+ MPH just to see how the car would do. This is
the same trip where the motor heated up terribly a while back with the NiCDs. When I got
to the destination I popped the hood and felt the motor cooling fins, which were just
barely warm. The motor controller was ice cold. Checked again when I got home and
nothing was hot. It is amazing to me how efficient that motor controller is -- no waste
heat at all! The trip was 14.3 miles and took 14.4 Ah. Not bad, especially considering
that there is some friction in the system from that dragging brake (or whatever it is).
Started a top-off charge when I got home and re-measured the voltages in the pack as it
was charging -- all batteries were at 3.35V (charge target voltage is 3.4V), no variation.
So, after I get the rubbing noise straightened out tomorrow and get the rear pack all
buttoned up, I consider this car 100% ready to go. All in all, a very easy upgrade. The
worst part was bottom-balancing all the batteries, which took about a week with two
Powerlab 6 chargers and battery swaps every couple of hours, with overnight discharges of
gangs of 3-4 batteries. Compared to the previous upgrade to NiCD batteries, which
involved massive amounts of fabrication work including coolant plumbing, this was a cake walk.
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