(ET) Buck/boost for E20 charger....

[Christopher Zach <czach computer org>]

Ok, this is going to be interesting.

So I came into possession of approximately 300 SAFT NiCD cells. Each 
cell is a BB600 form factor, and puts out 30-40ah at 1.2 volts. Flooded 
cells.

That's the cool news. What I want to do is put these puppies into my E20 
and get rid of the T105's. I think I can replace a T105 with 15 of these 
cells (5 cells wide=6 volts, 3 ranks deep=110ah) and get a tractor that 
will run full power in the summer, winter, etc for about 20 years per pack.

Problem is charging them. The E20's charger ramps up to 45 volts IIRC, 
is it possible to change the cap value and boost the voltage a bit 
higher? NiCDs like around 1.6vpc, or 8 volts per 6 volt battery or 48 
volts nominal. Add 2 volts to that for the battery control circuit I use 
(the TI DQ series) and I would need the Elec-trak transformer to put out 
a max of 50 volts.

SO any thoughts on getting that ferro-resonant transformer to have a 
slightly higher secondary without rewinding it?

Chris