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Discussion Starter #1
i.e. What technique?

I shift down to 3rd gear to avoid draining the battery. Reason: I figure using the energy directly:
engine--->wheels

is more efficient than indirectly:
engine-->motor-->battery-->motor-->wheels

That middle section (motor-->battery-->motor) wastes a lot of energy as resistance/heat.

.

Secondary Reason: To avoid heavy discharge of the battery which can lead to annoying recalibrations.
 

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I guess we have different mountains. I shift down to 3rd 'cause it won't keep the speed up in 4th. With occasional downshifting to 2nd on the curves...

I do tend to avoid having the assist on all the time, because it will only last for 1500-2000 ft of climb. Instead I nurse it along, and have gotten to where I can usually get the charge to zero as I get to the top.
 

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ElectricTroy said:
i
That middle section (motor-->battery-->motor) wastes a lot of energy as resistance/heat.
Only if you don't have to go back down the hill, or if you don't have to brake when you go down the hill so as to keep yourself from departing the portion of the downhill that is covered by the road. If you do need to brake going down the hill, then you will be dissipating energy that you could otherwise have stored in the battery.
 
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Hi ElectricTroy:

___Where do you live?

___I downshift on inclines as well but there really aren’t any steep mountains or hills in my neck of the woods. The worst climb I have is ~ 100’ over ~ ½ mile as the steepest portion of my daily commute. I just hit the trough at 55 + mph and finish off at 45 mph while still holding 5th gear without assist if at all possible … With a frontal wind, I will downshift to fourth.

___Good Luck

___Wayne R. Gerdes
___Hunt Club Farms Landscaping Ltd.
___[email:2m7ytjyz][email protected][/email:2m7ytjyz]
 

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Discussion Starter #5
Tim Maddux said:
ElectricTroy said:
i
That middle section (motor-->battery-->motor) wastes a lot of energy as resistance/heat.
Only if you don't have to go back down the hill, or if you don't have to brake when you go down the hill so as to keep yourself from departing the portion of the downhill that is covered by the road.
If you figure that regenerative braking is only ~30% efficient, you'd burn 100 watthours climbing... and only get 30 watthours back. To me, it makes more sense to avoid using the battery so you don't lose those 70 wh. i.e. Use energy directly engine-->wheels.

I stick to the interstates where the slopes are relatively shallow and 3rd gear is sufficient. And I can easily coast down without braking.

As for location, my Insight's been all over the country.
 

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CVT

On steep inclines, in my CVT I push the big white button marked "S" on my steering wheel (hey, it's for SECONDARY, not SPORT, according to my owner's manual!) and cruise up the hill at the speed limit. If it's a short hill, I don't bother with sport mode and just go to about 2/3 assist and keep to whatever speed that gets me.

Every so often, it's fun to just floor it and pass people while I'm going 80MPH in the left lane and accelerating :) Of course, those are the days when I go through some self-flagellation for having an MPG of less than 50 :)

Overall, I gauge the length of the hill. If I'm looking at more than a few miles of 6% grade, I hit the S button and go up the hill about 65 MPH. I hate looking at my gauge, but that way the battery lasts me to the top. My CVT has never gotten below about 30% SOC before it starts forcing a charge, and when that happens, even in S mode going uphill it's a bit sluggish for my liking...

The biggest difference between the CVT and the automatic seems to be in battery management. Well, except for the whole automatic transmission thing :) My CVT seems to just about always be "invisibly charging" (no green charge lights, but driving straight & level I can watch my charge-meter go up) if I'm anything below a bar below max. Then again, that's probably because I'm almost always driving in the dark or semidarkness and have my headlights on so I can see. Long workdays, short hours of sunlight up here in Utah this time of year.
 

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ElectricTroy said:
If you figure that regenerative braking is only ~30% efficient, you'd burn 100 watthours climbing... and only get 30 watthours back.
Try it a different way. Only use as much ASST to climb as you can get back from CHRG on the downhill.
 

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Discussion Starter #8
Ooops... double post due to forum error.
 

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Well maybe... it's hard to know how much charge you will get back. Often I get almost none, because the downslope is not steep enough.
 

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ElectricTroy said:
... it's hard to know how much charge you will get back. Often I get almost none, because the downslope is not steep enough.
Yeah, on gentler slopes like that I try to drive Rick Reece style... let myself decelerate up the hill and accelerate down, with a steady throttle position.
 

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I'm in California and commute from Santa Cruz to Mountain View over Hwy 17. There are probably others on this forum who do this same commute because I see Insights all the time (3 yesterday).

The hill on 17 basically goes up maybe 1500 ft and then down the same amount on the other side. I usually use 3rd and 4th gear climbing the hill and try to have the battery almost drained when I reach the top. Coming down the other side is more than enough to completely charge the battery from empty, even without being careful about it. During the climb I stay in the left lane and go the speed of fast traffic, around 55 - 65 mph (limit 50mph). On the flat parts of my commute I maintain between 60 and 70 mph. My overall commute mpg is generally around 65, although when I drive slower and more carefully I've gotten it up to a high of 82 mpg round trip!


Brett
2002 silver 5sp
45k mi, 62.5 mpg
 
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