# Amp draw on a Ninja 250 at cruise speed?



## whisperer (Sep 1, 2008)

Anyone ? I'm looking at a possible Ninja 250 conversion and am trying to get a ballpark figure for what range I can get out of it running an average 60 MPH. 
One possible motor/controller set I'm looking at is http://www.thunderstruck-ev.com/ddmotor.htm - the 25 HP set in the right side of the page. Good deal at the right HP.
Batteries I'm looking at are the Titanium 12 Ah NiMh. I can get those for $750 per 100 and that also seems like a good deal.

So that's 1440 Wh per 100. Question is what am I looking at for draw so I can figure how much range/battery.


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## frodus (Apr 12, 2008)

Lots of bikes I've seen use 125 or so WH/mile. So, if you want 20 miles, you do 20 * 125 = 2500Wh is what you'd need available. If you're using NiMH, I don't know what the DOD is, but lets say 80%, so you'd need 20-25% more... which is about 3125Wh.

Also, I'd recomend ditching the NiMH idea, because with those small batteries, each one has a welded connection, and each connection is a small loss, and each resistive loss will heat up at higher amperage. Try to get some larger format NiMH if you can, or go with Lifepo.

how do you get 1440Wh out of 100 of the 12Wh NIMH?


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## whisperer (Sep 1, 2008)

frodus said:


> how do you get 1440Wh out of 100 of the 12Wh NIMH?


Ya, OK, brain short. (stupid brushes anyway....  ) 12 AMP hours

12000 Mah = 12 Ah. 12Ah X 1.2VDC X 100 units = 1440 Wh.


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## frodus (Apr 12, 2008)

whisperer said:


> Ya, OK, brain short. (stupid brushes anyway....  ) 12 AMP hours
> 
> 12000 Mah = 12 Ah. 12Ah X 1.2VDC X 100 units = 1440 Wh.


OK, Gotcha.... still thats gonna be a lot of losses between connections. You typically want to keep the connections as few as possible.


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## whisperer (Sep 1, 2008)

*New info - Ninja 250.*

Well, it's official then. I struck a deal and will pick up my Ninja 250 on Saturday. So then, I'm building an electric motorcycle as my first conversion.


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