Re: (ET) batteries

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

Yes, lead batteries suffer mightily below freezing.  Will they still have 
enough capacity for your needs?  Much depends on "how cold," and "how 
long do you need to run."  Honestly, only experience will tell you.  

One thing's sure: the older the battery, the lower its capacity in the 
first place.  A battery is considered to be at the end of its life when 
it can no longer achieve 80% of its rated capacity.  I suspect that most 
folks run their ET batteries well beyond that point, but maybe your golf 
course people (the ones with the used batteries) don't.  Again, it 
doesn't cost much to try it.

You may be able to heat the batteries directly.  This is healthier for 
them than heating by overcharge.  You can buy little "hot plates" to put 
under the batteries; these low-power heaters can keep your batteries 
above 50 deg F (10 deg C) and do wonders for cold-weather capacity.  The 
only catch would be that many ETs have barely enough clearance below the 
seat already, and these would add some height.

Finally, as a last (and expensive) resort, you might adopt flooded nickel-
cadmium batteries (which might also require a charger replacement).   
Nicads are much less affected by low temperatures.


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 36 vdc