(ET) Shunts in for NiCD batteries

[Christopher Zach <czach computer org>]

Well, I finally put in the Link 20 meter for my Elec-trak. This is 
basically two Link-10 battery monitors with a special dual shunt. Now I 
can monitor each string of my two string NiCD battery pack and see if it 
slips out of balance.

Some things I have noticed:

While the tiller may seem to be a big accessory, it doesn't draw that 
much current. Maybe 100-120 amps while chewing. Part of the reason is 
the tractor is really *not* moving much with it; in fact the trick seems 
more to be use the brakes to hold the tractor back. The snowblower pulls 
a lot more power. Still, I only burned about 20 amps total plowing a few 
rows, not that bad.

The lift motors *really* throw packs out of balance. To the tune of half 
an amp for 10 amps drawn. That's about 5%. I vastly prefer running the 
rear lift on 12 volts; it runs a bit slower but I think it's going to 
last and that extra second doesn't mean much to me.

The Elec-trak's main charger puts out a solid 20 amps at 40 volts into 
the pack. Not too bad; it tapers down to 4 amps by 44 volts, and 2 amps 
by 44.5 (end of charge for the NiCDs.)

Chris