November 2008


Yesterday the truck failed an important test. It rained and it cause a ground fault. Even with all new seals on the lid and gasketed washers, it still ground faulted. So I got into the pack and checked for ground faults with the volt meter. The ground fault was floating around as it had on me earlier this year. So I tried the meter in low current mode set to milliamps. It showed the same location for a ground fault. Removing the cells showed some KOH streaking. Cleaning it up did not change where the ground fault was shown to be. So I went to the new process that I had figured out last Feb. I removed a cell interconnect at the lowest voltage reading relative to ground. I kept pulling one copper bar at a time until the voltage suddenly shot up. It ended up showing me that the ground fault was in the rear drivers corner of the pack. Removing the 8 cells in that area showed that there was water between the corner of the cell and the wall of the battery box. So I cleaned off the walls and cells with diluted vinegar and reassembled the pack. That took care of that ground fault!! This time I moved the mylar insulator into the corner to help isolate that corner cell from the box if it gets wet again. There is another smaller ground fault on the passenger side of the pack. I just vacuumed in that area and called it good for now.

The rear edge seal was a different material since I had run out. So I tore it off and installed the correct material. Since the two ground faults I found were right under that seal, this could help.

Also I adjusted the ground fault setting in the software to give it more tolerance since having 252 nicads or 504 terminals is almost 5 times the terminals that a regular lead acid pack would have. Between that and having flooded nicads, the pack is more prone to having ground faults. So I will see during the next rain how it all functions.

The #1 truck now has dual gas struts on each side of the bed. With my back trashed this week, it is very apparent that dual struts makes the bed easier to lift. It’s also a great benefit to not have to have a prop rod to hold the bed up. Ironically the bed now needs a rod to hold them from going too high up when I pull the truck in and out of the garage during repairs.

I also removed the class 3 trailer hitch to save weight. There is now a lot of room back there for an additional battery box. The roll pan is dented up from hitting the hitch when the bed tilted up. So I’ll have to smooth it out with an old cheap long flexible kitchen knife like I did with my first car about 30 years ago.

The battery box lid received new screws and sealed washers to hopefully help with making it more immune to water leakage and thus ground faults.

It’s been cold out. I am seriously thinking of taking the new upgraded heater out of the #2 truck and putting into the #1 truck. I suppose I could just buy a second new heater.

Here is the Thundersky BMs slave boards freshly mounted to the cells and about to be remounted into the truck. The BMS master board and LCD will be installed at a later date.

Here is the Thundersky BMS slave boards freshly mounted to the cells and about to be remounted into the truck. The BMS master board and LCD will be installed at a later date.

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