Of Questionable Metering

As you all know, I decided that I needed to approach some of the small problems I'm having with a much better plan. Ok, a plan, seeing as how I really wasn't using a plan before.

First, I unhooked everything from the high voltage system with the exception of the Link-10 meter. I decided I'd leave it like this through the weekend and check in periodically to find out how much electricity was being consumed out of the pack. I was absolutely astounded to see that in the first day, 24 hours, the meter reported that 700 watt/hours had been drawn off the pack. I figured that simply couldn't be true. That would be the equivalent of a 30 watt bulb burning during the entire 24 hours. If it is being burned off, I don't know where. There's nothing moving, glowing or getting hot.

I left the system configured this way all weekend, and what I found was that the meter, rather reliably, reported 700 Watt/hours for every 24 hours the car sat idle. By the time I got around to charging it tonight, the meter read that 2.5 kWhs had been drawn off the pack. I hooked the charger back up to the battery pack and plugged it in. Now the charger puts out 27 amps at 160 volts, or 4320 watts per hour. At that rate, it should have taken about 35 minutes to get to full charge.

I walked into the house to finish a game I was playing with the family, walked out about 12 minutes later to find the charger had shut off. I measured the voltage on the pack and found that it was at 166.8, which meant it was on it's way down from the 168 that I charge the pack to. I took a look at the meter and it said that I'd only replaced 200 Watt/hours of the 2.5 kWhs that had been pulled out. That could only mean one thing, that energy had never been drawn out of the pack. At the most, 200 Watt/hours had been consumed, and I'm reluctant to think it was even that much.

That means that something in the Link-10 is doing something wrong. If you look at the screen that shows amps that are currently being drawn, it shows 10 milliamps are being drawn off at any time. But the Link-10 is converting that into 700 Watt/hours over a 24 hour period. Clearly a math error or something more serious. I may be contacting Xantrex about this one.

You may remember that I had noticed that when all the systems were hooked up to the high voltage system, I was seeing something closer to 1 kWh a day being drawn off. Well, I can now account for 700 Watt/hours of that in just the internal errors in the Link-10. I now need to hook up each component one at a time to find out what's responsible for the other 300 Watt/hours.