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Could higher pack voltage be stepped down for Curtis input?

1922 Views 20 Replies 1 Participant Last post by  EVDL List
A single string of 17 group 34 batts (like Optima YTs)
could fit into my Geo Metro EV for 204 volts nominal.

Is there any way to step down that pack voltage to
around 150-160 volts for input into the existing
Curtis 1231 controller (rated 144v nominal max)?

The Geo EV's original converter did such a nice job
with the controller/heatsink/cooling fan installation,
that i can't bear the thought of ripping that all out
even if it meant replacing it with a zilla.


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· Registered
72,624 Posts
Discussion Starter · #21 ·
>> this doesn't like much more than a series of switches, and not
>> all that expensive. A reed switch on one cable, and a heat sensor
>> switch on the controller. What else did you have in mind that
>> drives up the cost to new controller range?

From: Peter VanDerWal
> Hmm well, a pair of highpower contactors (S1 and S2), a high power
> diode, and of course the cost of any extra low voltage controllers
> you happen to fry trying to get everything right.

The nice thing about this circuit is that the contactors and/or diode are fairly inexpensive and low-rated parts. At most, the current should be less than the controller's current limit. At most, the voltage across them won't exceed the 36v pack voltage. So, you can use low-voltage parts typically found in golf carts.

The hard part of this circuit is the control system. If you just throw it together with *no* control circuit, and depend on the operator to only open or close those contactors at the "right" times, then sooner or later he will mess up, and murder his controller.

"Excellence does not require perfection." -- Henry James
Lee A. Hart, 814 8th Ave N, Sartell MN 56377,
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