Eagletree Calibration
 

I picked up an Eagltree V3 e-logger (thanks Sower!) and did a little playing around to see what it could do. I hooked up some load resistors to an Elite 3s 3.3Ah pack to get some readings and was puzzled by the results. My 0.75 ohm resistor load was not producing the current calculated for the voltage displayed. Also, the battery voltage was not quite right either.

Turns out the voltage was displaying ~0.5v than it really was, and the current reading was displaying ~2A lower than it really was. I verified using my charger as a voltmeter and my Fluke meter in both voltage and current modes.

This was corrected by using the zero-calibration and V/A calibration functions of the ET software. Now, everything works perfectly.

Just a heads-up to others with an ET device so that you get the right readings. Obviously, you'd need another accurate form of measuring to get the correct readings to calibrate.

Glad I could help out :whistle:

:smile:

Mine was messed up too when I got it. Recal'd and it works great.

Does this mean you're one step closer to getting your battery testing project finished?

I have a ways to go still, but yes, one step closer...

Another little tidbit of data: In another thread, there was a discussion of why negative currents are not logged by the Eagletree device. It turns out that the Hall-effect sensor they use (at least the one I have) is unidirectional, meaning it only measures one way.

Oh, and the sensor part number is ACS754KCB-150-PFF

Yah, that is what I figured... I try measuring charging a battery with it one time, and nothing came up on the screen... so I made a couple of deans male-male and female-female adapter to wire up the Eagletree in reverse for that.

How do you guys run an ET in your vehicles without bending some pins?? No matter how well I secure it, somehow it comes loose and the pins hit something causing bending. Well, I cut up a spare computer IDE drive connector and voila, no more bent pins!

http://scriptasylum.com/forumpics/et_protector_2.jpg

http://scriptasylum.com/forumpics/et_protector_1.jpg

Yeah, I know: another useless innovation, but it has worked well for me.