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Old Apr 04, 2012, 02:41 PM
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Joined Jul 2009
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I have spent alot of time with castle on the phone discussing this and here are my findings and this has worked great for me:

You first need to establish a baseline of ripple current using some fresh batteries. Start by running up a simulated short flight on the ground.

Pull up the data from the logger and only view Voltage and ripple current

Use your curser to "box" the flight from the moment the voltage drops till it goes back up, this will remove the dead time and highlight only the flight its self.

Now take the avg ripple and divide it by the average voltage, this will be your baseline average ripple current. Ideally you want this number as low as possible (.01-.02 etc.) If it is over .05 or just under then you will have issues in the future (here is why) anything under .05 is fine but as batteries get older the average ripple current will increase, so if you are at let say .045 to start you will be fine for awhile but as the batteries age you will go over .05 and that can lead to problems in the ESC.

So lets say you have fresh battery packs but you are at .04 average ripple current. The solution is to add Caps,

You want to keep the caps as close to the ESC as possible, I use the meathod that Ron mentioned which is to slice off the top of the wire insulation, solder in the cap wires and then coat them heavily with Liquid Electric Tape. Works great.

I would start with 1 cap then run the flight test again and see how that helped the average ripple current.

My Falcon 120 has the ESC in the thrust tube back in the nacelle, The battery wires are pretty long but I soldered in 2 caps and with a slightly worn set of packs I am getting .023 Average Ripple current.

Now you need to monitor this over time and keep your eye on the average ripple current, you dont want to keep adding caps just becasue the ripple goes up, this is going to happen as the batteries wear. Ideally when you get to .05 its time to retire those packs. If you are at .05 with new packs then the caps are the solution.

Going the digikey route is great if you solder well, the castle route makes things easier but does cost more.

There are several guys that will come on here and balk about this post but here is the bottom line, if you want to play with CC ESC's then you should use their advice!! If you set it up this way and are monitoring temps, extending the fan spool up time, etc.. You should never have a problem, if you do its on them!

I watched a ICE2 HV 160 get pushed to 204 amps and 8600 watts fly a 25lb EDF this morning and it had a ripple of .018 and the max temp of the ESC is 124 and it worked flawlessly.
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