10-22-2010, 09:05 AM
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#3891 (permalink)
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Custom EV Builder...
Join Date: Jul 2009
Location: Ohio
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Quote:
Originally Posted by MPaulHolmes
Hopefully. Ain't nothing like actually trying it. What I think will happen is, the batteries sag right when the current goes up, so it probably won't get close to 200v. The spikes increase when the current increases, and the overall battery voltage drops, so everything is perfect!
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Should get a good test from my pack, I'm using A123s.  I had planned on building my pack to 156v to compensate for sag. Is this something I should be concerned about? If so, should I consider building the unit with some different mosfets? Possibly TO-263 IGBT's?
Last edited by wakinyantanka; 10-22-2010 at 09:12 AM..
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10-24-2010, 08:13 AM
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#3892 (permalink)
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Master EcoModder
Join Date: Sep 2009
Location: Ireland
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Here's a few pics of a new controller build i'm undertaking. Its for a friend in the uk with a modest 72v system. Its being built with mostly recycled hardware and i'm putting together a series of videos on the process :
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Now, Cole, when you shift the gear and that little needle on the ammeter goes into the red and reads 2000 Amps, that's bad.
www.evbmw.com
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10-24-2010, 09:01 AM
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#3893 (permalink)
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EcoModding Lurker
Join Date: Jun 2010
Location: Madison, WI
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Looks like over compensation with those lytics 
Very nice work. It's a shame to use 450V caps for a 72V system, but if they are salvaged......
BTW where did those come from?
JAK |
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10-24-2010, 09:07 AM
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#3894 (permalink)
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Master EcoModder
Join Date: Sep 2009
Location: Ireland
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Most of the bits came from scrap inverter welders and plasma cutters. I have a friend who owns a welder repair shop and every now and again he calls me to come clean the place out of all the machines that people basically abandoned. The caps came from a 3 phase plasma cuter. I know the hv caps are sort of wasted BUT that hv tolerance can only help with spikes etc.
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Now, Cole, when you shift the gear and that little needle on the ammeter goes into the red and reads 2000 Amps, that's bad.
www.evbmw.com
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10-24-2010, 11:35 AM
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#3895 (permalink)
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Master EcoModder
Join Date: Sep 2009
Location: Ireland
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Few more pics of the casing , end caps and fan mounting. End caps are 6mm polycarbonate.
__________________
Now, Cole, when you shift the gear and that little needle on the ammeter goes into the red and reads 2000 Amps, that's bad.
www.evbmw.com
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10-25-2010, 02:28 AM
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#3896 (permalink)
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dwffy
Join Date: Jul 2009
Location: Calgary - Canada
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Hi again,
Well ever since I recieved some good advice here on the forum about my controller, I have now completed my Ford Ranger and it goes better than I had hoped for. I will be sending it in for its final registration inspection next week and hope to have it on the road within 2 weeks time. I'm really lookin forward to putting some EV miles on it. Thanks to you kind folks here, I have been able to solve most of my mysterious problems with it. I am however not finished asking questions though. I need the make a DC-DC converted (120v - 14.1V) to keep my vehicle battery (12volt) continiously charged. I have obtained a controller with a faulty primary board off a golf cart. I have replaced the mosfets with ones of higher operating voltages and replaced the caps with higher specs too (140v). Will I be able to use this as a dc-dc converter if I use a simple PWM made with a 555 IC and set the voltage to say 14 volts. I obviously don't need more than 20 amps max, so I can cut down on the number if Mosfets that I use. That's my theory anyway.
Any help here will be greatly appreciated.
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10-25-2010, 05:33 AM
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#3897 (permalink)
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Master EcoModder
Join Date: Sep 2009
Location: Ireland
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Sadly that won't work as you need an isolated converter. You could make a buck converter with that old controller but it would not be isolated from the traction pack and going from 120v to 12v would be at the lower limit of that design. Sad as it is to say its not really worth doing homebrew. You can pickup a 600w dc dc for less than 100usd these days. Or look at modifying a powersupply.
__________________
Now, Cole, when you shift the gear and that little needle on the ammeter goes into the red and reads 2000 Amps, that's bad.
www.evbmw.com
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10-25-2010, 12:42 PM
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#3898 (permalink)
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Master EcoModder
Join Date: Sep 2009
Location: Ireland
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More pics 
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Now, Cole, when you shift the gear and that little needle on the ammeter goes into the red and reads 2000 Amps, that's bad.
www.evbmw.com
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10-25-2010, 12:49 PM
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#3899 (permalink)
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AC-DC enthusiast
Join Date: Nov 2009
Location: Long Island, NY
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Quote:
Originally Posted by jackbauer
more pics
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nice !!!
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. .. .. . .... ...
Prius Absolutum Dominium . ..........KOPPER
PHEV conversion since Dec 2006.. . .... .Future EV
. . . . . . . .CALCars # 27. . . . . . . . . . ..on the works now !!
. . . . . . . . . . . . . . . . .. . ........
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10-25-2010, 10:38 PM
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#3900 (permalink)
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EcoModding Lurker
Join Date: Sep 2010
Location: st. louis
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Has there ever been a case where the board simply will not work even though the warning light (yellow LED) stays lit doesn't blink? right now I have the it hooked to my power section and the car is on jack stands I twisted the throttle and nothing happened then I took it off the stands and put my foot on the pedal nothing happened??
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