Re: (ET) monitor

[Chris Zach <czach computer org>]

There is an enhancement I am working on: The disadvantage of a 
resistor/diode bridge is that it is always drawing a bit of current from 
the pack. Over a week or two that might add up. I think it's around 
22ma, which equals .5 amps per day or so. Over the course of a week, 
you're talking around 3.5 amps. Still will take awhile to burn down a 
200 ah battery.

I just placed an order for 28 power controller boards. Basically a 
relay, fuse, and places for the wiring to go. The idea is that each 
battery gets a relay circuit which provides the fusing to the battery 
(really important) and keeps the circuit off unless +36 volts is 
provided to the three relays running in series. 25 of these will be used 
in my electric car, and three will be for the E20.

The thought is when the tractor key is off, the relays are down and the 
circuit is off. Turn on the key, the relays engage and the circuit comes 
on.

In the meantime I have a 4 fuse array in the back of the tractor, and a 
two fuse array up front. Attach the sense leads to the fuses, and attach 
the fuses directly to the battery (putting them on the battery clamp 
bolts works great). Whatever you do don't try measuring current across 
tractor wires (you have to measure at the batteries themselves) and 
please please use fuses. T105's will melt wires instantly in a short 
situation.

Chris