RE: parallel packs?

[Larry Elie <lelie ford com>]

----------
From:   Max Hall[SMTP:maxo iname com]
Sent:   Saturday, January 02, 1999 7:32 PM
To:     elec-trak discussion list
Subject:        parallel packs?

Happy New Year, everyone!

We're finally getting our snow up here in the NE, and that means it's time
to throw snow with the E-15. Huzzah!

I have a battery back question. First, some background.

I am running on an old sextet of batteries (6 years and a lot of sitting 
and
they still perform admirably.  Fine. Next item.

I didn't have a weight box attachment, so, for counterweighting, I built
what looks like a back porch on the tractor to support some serious heft.
During construction, it occured to me that instead of using cement blocks 
or
what all, I could have counterweights that deliver power. I have another 
set
of 6V cells (Trojans that would fit the E15 both physically and
electrically) that came from an EV that wanted fresh batts. (They are in
good shape, as measured by a DVM.)

Anyway, here's the nub: should a person put a second pack of batts in
PARALELL with the first, or should I SEPARATE the circuits to make the
traction pack drive the tractor, and the second pack just do the thrower?
(If the circuits are separated, I would be able to use a set of 350A
contactors from another project to drive that great big two-state device.)

Larry Elie's (delightful and interesting) thoughts on the phenomenon of 
cell
imbalance didn't seem to me to favor either method.

Thanks for your thoughts, folks. Here's to playing with great big 36v toys
in the snow.

- Max Hall
- www.maxmatic.com

The simplest is just to parallel two sets of 36V packs, as GE did as an 
option.  
Your lift batteries will go low first.  To get more cleaver, you could 
parallel up 
in pairs (of 6V) or one 12 to two 6Vs, but you would have a hard time even 
getting all the cables under the seat.

Larry Elie