Friday, July 16, 2010

Not Much to Report

Everything has been running smoothly this past week. The few times I took the car out, it hummed along effortlessly, with no hint of a problem. For those of you not following Arizona's weather closely, it's been hot. Hotter than usual. Yesterday was 116 °F with humidity near 50%. There was no way I was taking the car out in that weather. Remember, no AC.

I'm continuing my tests this weekend to see if I can find which component is leeching power from the batteries when the car is off. So far the only configuration I've tested was to have the Link-10 meter hooked up by itself. You may remember that it reported 700 Watt/hours being drawn off in a 24 hour period.

The Link-10 will remain hooked up the entire time, after all, I need to monitor the pack during the test. But based on the previous test, we know the Link-10 brings along a 700 Watt/hour per day draw to the test. So I expect that if a component is drawing current, I should see more than a 700 Watt/hour per day reading on the meter.

Well, it's time to hook up the next item, and I need to choose which one. I still have to test the Zilla controller, the heating element, the charger and the DC to DC converters. Since the DC to DC converters have been fooled by the hot weather into thinking that they are too hot, their fans run constantly. So I think it's best I skip testing them for now. I think I'll move next to the heater.

Now the ceramic heater draws it's power directly off the traction pack, but it's behind two relays and a manual switch. In other words, in order for it to get any power, the car's HVAC fan has to be on, triggering the first relay. That makes the switch on the dash live. That switch must then be activated in order to trigger the final relay that actually sends power to the ceramic heater. So what are the chances that the heater is drawing any current when the car is idle? I'd say 0%, but I set out to test this methodically, and that's what I'm going to do.

I may not give the heater the full weekend to test it. If I see no change from the 700 Watt/hours I expect from the Link-10 in the first 24 hours, I'll add the next component and start the next test.

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