Truck #1 (Nicad)


Starting last night I drove the pack down until it was only around 200v. Then pulled it into the garage for discharge maintenance. I made up a system using six 2000w, 120vac water heater elements to discharge the pack in large groups rather than just two groups.

Here is the pack attached to all of the water heater elements. A 5 gallon bucket of water was used for cooling since an experiment with air cooling caused the elements to glow red, which is an ignition source. The water level dropped about 3/4″ when the pack was done discharging.

I used my cnc to machine 6 holes in these two pieces of 3/8″ thick plywood. They held the heater elements 3″ apart and 3″ from the sides of the plastic bucket.

After the overnight discharge was complete, I put some jumpers across about 5 cells that were still showing some voltage (not shown). Shown here is the 240vac variac and a bridge rectifier mounted to it’s heat sink. It takes me about 45 minutes raising the voltage by hand, to about 320vdc. After that, the on board charger is used to finish up the charging.

11jan2011 22648 miles, recharged pack, +4.98kwh, 11.88kwh total, no o/c time. Refilled bearing reservoir with Mobile1.
10jan2011 Flattened entire pack. Jumpered redtop cells.
10jan2011 drove deep discharge, -6.90kwh.

Watered entire pack, 22627 miles, many cells very low. 3.7 gallons H20.

Set charger to 2 minutes of constant voltage time.

10jan2011 22627 miles, watered entire pack. Many cells very low. 3.7 gallons H20.

09jan2011 Drove, deep discharge, -6.93kwh, recharged 2.77kwh, 9.70kwh total. Pack was very stiff during charging and driving.
09jan2011 Recharged flattened pack, +5.88kwh, 11.18kwh total. 20 cells appeared shorted. After 30 minutes of charging they all appeared normal. Cells are marked with a red circle on their cap.
08jan2011 Flattened entire pack, -5.30kwh, 18.9ah, 19.1miles, 11:35pm.

07jan2011 Recharge.+2.94kwh, 8.73kwh total.
06jan2011 Drove deep discharge,-5.79kwh

06jan2011 Recharge, +2.18kwh, 6.53kwh total.
05jan2011 Drove deep discharge, -4.35kwh

27dec2010 Added 10 used and tested nicad cells to pack. 251 total. Set charge voltage to 400vdc.

16dec2010 +3.86kwh (8.3ah) on recharge. 11.19kwh (35.7ah) total recharge.

15dec2010 +4.55kwh on recharge. 11.59kwh total recharge.

15dec2010 -7.33kwh (27.4ah) @ 30.1 miles, 244.3wh/mi, dry, sunny, warm. Errands, highway and city driving. Heater. SJ loop.

14dec2010 -7.04kwh @ 27.7 miles, 254wh/mi, raining, cold, dark, no no heater. SJ loop.

241 cells installed. 2 shorted green top cells removed. 24 Redtops watered. 3 clear tops watered.

27nov2010 -4.55kwh, 20.3 miles, 243wh/mi

26nov2010 -4.13kwh, 15.55 miles, 265wh/mi

I’ve been working like a dog on making an electric vehicle system for a guy on the east coast. It’s been assembled for days. Runs too. But it has this kind of miss to it. Almost like it’s got one bad spark plug wire. It just runs rough. I’ve not seen that kind of problem before with an AC electric vehicle system.

Also have the spot welder nearly assembled. It just needs some finishing. I hope to create a process to spot weld braided flat cable to lithium battery cells. The cable allows flexing without breakage. Mostly for our combat robot buddies. For automotive use it’s not really necessary. But it will be a great process to have under my belt.

After this system gets shipped, I have gathered all of my hand drawn individual schematics, and will create one large schematic for the entire Dolphin main board. I have almost every square inch documented. Just a little remains. But even a mostly completed schematic will be helpful in debugging. I’m still deciding what cad package to use.

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