Re: (ET) Elec-trak Digest, Vol 23, Issue 34

[Dave Tiefenbrunn <davidtief comcast net>]

Some of this might be helpful info...

I have an E-14.  It has a PM main drive motor.  I have a .001 ohm 1KW 
resistor that is made for doing high current measurements. Years ago, I 
wired it in series with the drive motor, and used a storage oscilloscope 
to capture the peak current surge when hitting the power pulse button 
with the rotor locked.  [I put the tractor against an immovable object, 
and left it in D2]  The peak current was 300 Amps, which then quickly 
dropped, limited by the internal resistance of the LA batteries, and 
tractor wiring. When I decided to convert my ET to lithium batteries, I 
found surplus lightly used batteries that were used in the BMW i3.  They 
are rated to deliver 150A continuous, and 300A for 10 seconds. 75AH 
capacity.  I have 2 of these wired parallel, with a JK BMS. Mowing, the 
current is mostly between 50-75 Amps, depending on flat / hill / grass 
height / travel speed.

Dave