Way too many years ago (1990's), I poured money into upgrades for the S-10 Blazer conversion EV I had (see https://brucedp.neocities.org/blazer/ ). The now retired San Mateo converter installed a small simple circuit that helped maintain a constant battery current draw. I was lucky to get one as this was how he won EAA distance rally races.
It basically was a dash mounted: flip switch, push button which engaged a relay that then used a knob'd potentiometer as the control to the controller (the relay took the foot accelerator out of the loop/circuit). Routinely checking my dash cluster mounted link-10 e-meter (looked like: https://sc02.alicdn.com/kf/HTB13HUeKFXXXXX4apXXq6xXFXXXe/Xantrex-Link-10-formerly-E-Meter-.jpg http://www.solarray.com/Images/ImagesEVs/Meter.JPG -now sold as: http://www.xantrex.com/power-products/power-accessories/linkpro-battery-monitor.aspx ), I could see the battery current held steady on the flat, would naturally slow down & draw more battery current on the uphill (e-motor under more load), and would speed-up & draw less battery current on the down hill (e-motor under less load). In a effect, it was the same effort a human makes to keep their foot on the accelerator steady as a rock (without the human repeatedly re-adjusting the accelerator position, which wastes power). Like an ice cruise control, it had the nice effect of letting my foot take a break from having to depress the accelerator on long trips (one less thing to do as part of the constant vigil while driving). BTW, there were micro switches on the brake and clutch levers, that would disengage the circuit, putting the accelerator potentiometer back in control of the controller if there was a panic change, etc.. But as Tom inferred, that up/downhill change in speed would be a pain(pita) for the drivers behind you (ticking them off to do something dumb, etc.). However, in fact my multiple experiences using this nifty circuit was when I drove 160 miles from Silicon Valley to Sacramento (to hang out with the Nedra.com e-racer folk by charging multiple times off the public 6kW Avcon EVSE), by staying the right lane, I minimized that pita effect. The right-lane racing fools that thought tailgating would make me speed up, were educated after reading the ELECTRIC signage and hov/car pool lane stickers on the rear of my EV, and just passed on the left into the faster lanes. For most drivers behind me, it wasn't as bad as I had feared (and CA drivers can be a real obnoxious bunch). Having said what I really experienced, I agree with Tom, that it would have been sweeter to have a way to maintain speed on the uphill, and use regen on the downhill (my Blazer did not have regen like today's AC motor controllers do). So, how does one put more energy into the climb, or less energy on the downhill without varying the current draw on the pack? The only solution I envisioned was more complex and expensive: -a buffer pack (perhaps either a prius NiMH, or a small amount of ultracaps) to draw from and capture the regen when either climbing or on the down hill. That smart cruise control would truly have to be smart to: sense the EV's speed, demands on the e-motor, the battery current draw, and control the power going in and out of the aforementioned buffer pack. It makes you wonder what we (drivers) will do to maximize range. For EVLN EV-newswire posts use: http://evdl.org/evln/ {brucedp.neocities.org} -- View this message in context: http://electric-vehicle-discussion-list.413529.n4.nabble.com/Smart-cruise-control-tp4685950p4685979.html Sent from the Electric Vehicle Discussion List mailing list archive at Nabble.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)
