From: lektwik via EV <[email protected]> >96V = Slug Not necessarily; but in this case, probably correct.
Here's my guess: A 6v golf cart battery has an internal resistance of about 5 milliohms (0.005 ohms). A 96v pack has 16 of them; so the resistance is 0.005 x 16 = 0.08 ohms. Let's say the Zilla limits voltage to 72v (i.e. it won't pull the pack below 72v). Then the most current you can get is I = V/R = (96v-72v) / 0.08 ohms) = 300 amps. In practice, the resistance of the pack is a bit higher due to the wire and connectors. So a 200a max current is probably the most you can draw from the golf cart batteries before their voltage under load falls to 72v. Now, if you had a different kind of batteries with less internal resistance, or a controller that would cheerfully pull the battery voltage even lower, you'd have a lot more current, and peppier performance. For example, my old ComutaVan had a 72v pack of golf cart batteries, and a contactor controller. It would cheerfully pull 1000a from the batteries, and spin the tires if you "floored it" from a dead stop. I tried a Curtis 1221 400a controller; and it was *worse* than the contactor controller for accelleration, because it never came anywhere near 400a due to voltage sag. -- Excellence does not require perfection. -- Henry James -- Lee A. Hart http://www.sunrise-ev.com _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org Read EVAngel's EV News at http://evdl.org/evln/ Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/group/NEDRA)
