Re: (ET) controller, today and tomorrow!

["David Roden (Akron OH USA)" <roden ald net>]

From:                   "Monty McGraw" <mmcgraw74 hotmail com>

> To charge the system I bought a Trace DR-1500 inverter charger which
> requires a 24v battery pack .... The Trace inverter can do 1500watts
> continuous ... As a charger ... 50A in bulk charge mode and has 
> microprocessor algorithms to taper the
> charge ...
> 
> I bought a small 1QD-70 amp controller (48v) to drive the mower deck at
> 36v ... I'm trying to avoid tapping the battery pack, so I don't
> end up with weaker batteries that get undercharged.  I think that by
> putting the two 24v strings back in parallel (when the tractor is off),
> that the stronger side will dump current into the weaker until they are
> better equalized.
> 

This sounds like a super-deluxe upgrade!  You've done quite a job. 

Charging the two 24v strings in parallel should work fine.  There are 
plenty of 48 volt smart chargers available, but I don't know of any with 
built in inverters -- a really useful feature.

I agree, not tapping the pack is a very good idea.  The problem then is 
to find 12v and 18v power for the lift and lights.  I've run my lift from 
12 volts and 24 volts; 12 volts is a little feeble, but tolerable (using 
the doubled-over format for the mower, as you do with the blade, helps).  
You might consider a small Curtis or other 13.8 volt DC:DC converter to 
run the lights and lift, or even a small, separately charged U-1 size 
deep cycle battery.

Mark Hanson runs his ET on 48 volts, and I think he runs the mower at 
that voltage too.  It would probably be OK, but your approach is probably 
the safer one.

Congratulations on your work!


David Roden - Akron, Ohio, USA
1991 Solectria Force 144vac
1991 Ford Escort Green/EV 128vdc
1979 General Engines ElectroPed 24vdc
1974 Honda Civic EV 96vdc
1970 GE Elec-trak E15 36vdc