Cycle Analyst Rshunt setting/calibration

Hi all
There is no fualt in the Cycle Analyst
let me get that straight first.
This thread has been done due to the popularity of the CA and the fact there is nothing else like it out there.

The Guys at Ebikes.ca do a great job the Direct Plugin Cycle Anlyst or DP CA, when you buy a controller and a DP CA from them the settings for the shunt resistor are programed in by them,this makes things easy, however many of us started before the CA came along and so had to use devices that were designed for the R/C market, watts up,doc wattson and the power analyser family from Medusa com to mind (me I had a power analyser pro), to my knowlege most had a voltage limit of 60v mine did, so when the drain brain came along the voltage limit was off.
Now we have the DP CA that has all the features of the drain brain plus the ability for the first time to aply control to the controller.Many of us already had speed controllers and wanted to upgrade to a DP CA, with this in mind Ebike.ca added to there website pictures of how to wire 20a and 35/40a x'tlyte controllers for a DP CA at your own risk they also sell the short cable terminating in the correct plug for a DP CA.
There are now more and more controllers coming on the market and one of the first things one or other of us at ES does is to work out the wiring for the DP CA,the guys at Ebikes.ca have no knowlege of the shunt setting for all of these other controllers or if the shunt in a controller that came with a DP CA has been modified I belive you can add solder across the shunt.
So there you have it a great product with a lot of retro fits out there and some may not be giving true readings through no fault of Ebike.ca if the settings are set incorrectly then you can't expect to get the correct results out the other side, with a cycle computer if you don't put the correct circumfrence into the settings you can't expect to get an acurate speed, you dont blame the manufacturer for that do you.what I am providing is a spread sheet for exel that should help to zero in the diffrence between a know reading and a DP CA reading.

requirments for this are
exel from 2003 or later
the DP CA you wish to calibrate
a drain brain, watts up, doc wattson, power analyser or any other type of device that can mesure amphours acuratly.


I will be setting up a feedback thread in e-bikes review and testing http://endless-sphere.com/forums/viewtopic.php?f=4&t=6104 post your comments there.

hi all
two things one I do not take credit for the formula to reset the Rshunt value that came straight from the guys at Ebikes.ca, what I take credit for is the spread sheet that I built using that formula which should make it easy,in theory the first time you reset the Rshunt should be the only time, the reality is that the formula will overshoot but as you get closer to the correct figure the overshoots will get smaller till you get a number you are happy with. I will post the spread sheet I have that I used to calibrate my Rshunt setting in a few posts I still have it but it is on a cd rom somwhere.

hi all
a new problem has come to light.:-
some of us do not have a control meter that can mesure amphours
this is not whitout a soloution, when I first inquired of Ebikes.ca on how to reset the Rshunt I was told I could use either a control meter which I had and I think would be more acurate so as a result I did not mention the second method that Ebikes.ca suddgested was to use a battery pack of a known size this I felt would be unreliable as you can lengthen or shorten the capacity of a battery depending on how hard you use the motor.
The method is as follows:-
in the first column the control figure is put, normaly you would have setup a control meter and use the amphour reading on this, the alternative is to use the battery of known amphours and put that in the first column to get a close figure KEEP YOUR CURRENT DRAW TO AROUND 1C not less not more as close as you can most batteries will give an acurate amphour output if a load of 1c is put on them. I have had somone with this need post on the feedback thread he has a 5.2ah battery,so in the control column he should put 5.2 in the CA column he should put the amphour reading on the CA I belive he has a LVC and will take the reading after the first time the LVC kicks in. the spread sheet will calculate the rest, it will take time but a CA can still be calibrated this way.

hi all
I have just recived a new controller that has been wired for a DP CA.
I'm going to set up the controller to run at 48v with both a DP CA and a control meter then I will find out what setting the Rshunt should be set to using the spread sheet to do it, I will document it as I go along. this should show you how to use the spread sheet.