# DC - Not ypur best hill-climbing device



## peggus (Feb 18, 2008)

All they are saying is that series wound motors don't regulate speed well on their own. Their speed will vary greatly with load if driven from a constant source. The same goes for ICE by the way.

Your conclusion that this means they can't climb hills is wrong since there is a speed regulator behind the steering wheel, you, who will apply more throttle to maintain the speed.

For what it is worth my series wound dc driven EV climbs hills just fine, I have no problems accelerating uphill in fourth gear.


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## corbin (Apr 6, 2010)

efan said:


> hey guys,
> i could not find much information on this topic, so I wanted to find out if someone here has experience they can share on the topic
> 
> *[top]The Bad: Not your best hill-climbing device.*
> ...


My 1969 VW bug, with a Warp9 DC series wound motor, climbs Highway 17 in santa cruz with no problems at 55-60; it could probably go faster, but the bug corners horribly, and the road isn't straight. It generates quite a bit of heat climbing the hill, but seems to be within limits (<80-90 C). 

25% grade is really high. I think highway 17 is 10-15% at most. 25% grade is *really* steep. The steepest grade in San Francisco is around 30% grade. i doubt you have a 25% grade that you'll be going 65 MPH on, but I could be wrong!

My car is not an NEV; it is a full on EV.

corbin


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## efan (Aug 27, 2009)

corbin said:


> My 1969 VW bug, with a Warp9 DC series wound motor, climbs Highway 17 in santa cruz with no problems at 55-60; it could probably go faster, but the bug corners horribly, and the road isn't straight. It generates quite a bit of heat climbing the hill, but seems to be within limits (<80-90 C).
> 
> 25% grade is really high. I think highway 17 is 10-15% at most. 25% grade is *really* steep. The steepest grade in San Francisco is around 30% grade. i doubt you have a 25% grade that you'll be going 65 MPH on, but I could be wrong!
> 
> ...


Thanks for the replay, it was helpful!!...the 25% grade is just a guesstimate as I am not sure what the exact number is...do you think an AC-50 would work better than an 11" DC (at ~200V) motor for the above situation?


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## corbin (Apr 6, 2010)

efan said:


> Thanks for the replay, it was helpful!!...the 25% grade is just a guesstimate as I am not sure what the exact number is...do you think an AC-50 would work better than an 11" DC (at ~200V) motor for the above situation?


For hill climbing? Either would probably be sufficient. You mean the Azure Dynamics motor? 

An 11" DC would probably be fine propelling any car up a hill at whatever speed you wanted.

The advantage of an AC motor is when you come down the other side of the hill; you will regen some power lost on the uphill. How much it helps and gains in range -- I don't know. I do wish I had an AC system simply because I don't have power brakes and it just seems a waste when I drive down a big hill every day!

Also consider the AC systems from EVE. And read my blog.

http://www.corbinstreehouse.com/blog/2010/04/plug-bug-ev-ac-drive-motor-controller-selection/

corbin


corbin


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## JRoque (Mar 9, 2010)

Hey Corbin, just went through your blog. That is excellent info you got there! I'd suggest you add it to the wiki here or at least a link back to your site.

Have you considered the new 650A HPEV package as a possible replacement for your DC system? Beyond including almost everything you would need for a basic setup, the motor will bolt your your existing DC mount and adapter which minimizes your replacement costs.

That said, the gain you will get from regen will likely not be enough to offset the loss in pack power when you have to drop to 120V. Keep in mind that you still have to do 55-65 MPH so there's only so much you can regen back. With $4500, I'd upgrade your DC controller to higher voltage (if needed) and buy more cells to increase your range and power, keeping everything else as is.

JR


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## corbin (Apr 6, 2010)

JRoque said:


> Hey Corbin, just went through your blog. That is excellent info you got there! I'd suggest you add it to the wiki here or at least a link back to your site.
> 
> Have you considered the new 650A HPEV package as a possible replacement for your DC system? Beyond including almost everything you would need for a basic setup, the motor will bolt your your existing DC mount and adapter which minimizes your replacement costs.
> 
> ...


Hey JR, yeah, thanks! I need to still re-organize and categorize things on my site for easier access. Going through posts backwards is kinda slow. Once I get it setup I'll add some links from the wiki. I learned most of what I know from this forum, and the EVDL.

Yes, I wish the 650A curtis was available when I started my conversion; that would have been totally fine for my needs. I still think the 9" DC + Netgain controller will be faster, but I don't necessarily need speed in my bug. (Actually, I think Jack Rickard proved the 9" DC system is faster with a 1000amp controller). Since I'm already setup with the Netgain system, I probably won't swap it out. I'm fine with range with my typical driving, and met my goal of only charging at work during the week. The other problem is dropping the pack voltage from 154v nominal to 120v(as you noted). I may reconsider it when they have a higher voltage curtis controller. Or, I probably will just make another conversion at some point. I really want a Factory Five 33 roadster!

corbin


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