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Old Jun 05, 2010, 12:56 PM
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E-Challenged's Avatar
United States, CA, Garden Grove
Joined Oct 2000
11,832 Posts
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Simultaneous LVC Cutoff of Twin Motors Using Smart BEC

In my present ME-262 setup, one of my two ESC's will go into LVC and cut one motor, the other ESC and motor continue to run with unplanned aerobatics and loss of control due to assymetric thrust. I have to avoid LVC or cut throttle instantly and regain control for dead stick landing if high enough or keep flight times short to avoid the problem

I have been told that Dimension Engineering's Smart BEC has an LVC circuit that can be used to cut both motors at the same time when motor battery voltage sags. Trying to get specific how to wiring information from Dimension Engineeering, Castle Creations and other E-Zoners. I think this is important stuff for any multi-brushless-motorered EDF or prop model

Here's my thread with a wiring diagram, I think that I'm almost there:

http://www.rcgroups.com/forums/showt...2#post15245895
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Old Jun 05, 2010, 09:43 PM
59 years of RC flying
Daedalus66's Avatar
Canada, ON, Ottawa
Joined Feb 2006
16,125 Posts
If you EVER see LVC you are not managing power correctly. Every time you hit LVC you damage the battery. And the damage is cumulative.

By timing your flights, measuring resting voltage carefully and noting the amount you put back into the battery when charging you can ensure that you never use more than 80% of the battery capacity. That way batteries can last years.
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Old Jun 06, 2010, 10:27 AM
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United States, CA, Garden Grove
Joined Oct 2000
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I don't need "Power Management 101 for Newbies" . I have been doing exactly as you recommend keeping flights short enough to avoid possiblity of LVC one motor out. You should know that lipo packs in EDF's are typically stressed a lot and will change capacity and duration over time so that the LVC thing can happen, especially if you have to "go around" a couple of times due to other traffic after a 4 minute flight. I just wanted to share something that would offer a measure of protection for multi-brushless EDF's and prop planes.
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