Canít Calibrate eLogger V4 - Extreme spurious results - RC Groups
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Mar 07, 2013, 02:04 PM
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Ken Myers's Avatar

Canít Calibrate eLogger V4 - Extreme spurious results

Iíve been learning about the eLogger V4 for three days now. I cannot get consistent results when trying to calibrate it or use it.

Yesterday I did a motor test comparison using the eLogger V4, Emeter 2 with a CC Ice 50 ESC. The data was captured. After the battery was plugged in the Emeter 2 read 14.15v, 0 amps and 0 RPM, the eLogger V4 captured 14.18v, 0.30 amps and 0 RPM, and Ice 50 14.16v, 0 amps and 0 RPM. The eLogger V4 had been zeroed following the procedure in the manual before this test was run.

This morning, without changing anything in the eLogger calibration, I got some very odd results while trying to figure out how to calibrate the unit better.
The term voltmeter in the following refers to a Radio Shack Digital Multimeter Cat. No. 22-168A.
Battery 5S ďA123Ē 2300mAh
The voltage was read by pins inserted in the battery leads. There was no load on the eLogger.

Test 1 showed spurious 0.12 amps and 18.18 volts for the eLogger V4, while the voltmeter read 18.17 volts and then dropped to 18.16 volts.

Test 2 hooked up brushless RPM sensor. Voltmeter read 18.16 volts and then 18.15 volts. The eLogger V4 showed 0.12 amps for a bit and then stopped. Spurious RPM data was recorded ranging from 17 RPM to 576 RPM with a total of 15 records out of 57 records showing RPM data. Voltage on eLogger showed 18.18 volts and dropped to 18.11 volts at end while the voltmeter showed a voltage no lower than 18.15 volts.

Test 3 the brushless RPM sensor was place on a cardboard box up off of the marble counter top. The voltmeter reading started and spent most time at 18.15 volts and then dropped to 18.14 volts. The eLogger data showed just four 17 RPM readings near the beginning of the recording. The eLogger showed 0.0 amps through test. Why it stopped recording amps is uncertain as nothing had been done to the eLogger. The eLogger volts started at 18.18 volts and dropped to 18.16 volts near end with no record of 18.17 volts. It went right from 18.18v to 18.16v.

Test 4 used the same setup as test 3. The voltmeter read 18.14 volts through the whole test. The eLogger showed 18.09 volts through test and had 5 rpm data captures at the begging of 170 RPM. The eLogger amps were recorded at 0.0. I had made no calibration changes to the eLogger but it showed less voltage than the voltmeter on this test, while it had previously shown a slightly higher voltage.

Test 5 was a double test. For the first part of this test the voltmeter reading started at 18.14 volts and dropped to 18.13 volts. The first eLogger capture showed 18.09 volts throughout the test and 3 spurious rpm records and 0.0 amps. A timer was set for a minute and then the second capture completed. The second voltmeter reading was 18.13 volts for the whole time. The eLogger showed 18.16 volts for two captures and then dropped to 18.13 volts and then dropped to 18.11 volts and then dropped to 18.09 volts and then 0.0 volts. While at 0.0 volts it showed 0.12 amps and then 0.18 amps.

I was totally confused and frustrated with the results.

I hooked up the Emeter 2 RDU (remote data unit - captures data like the eLogger does) with its phase sensor (brushless RPM sensor) attached and repeated the test exactly the same way I had for the eLogger V4. The voltmeter read 18.10 volts through the whole capture time. The RDU captured data showed 18.10 volts, 0 amps and 0 RPM through the whole capture time.

Is there anything I can do to get consistent results with the eLogger V4? Right now I have no faith in the accuracy or recorded results of the eLogger V4. There is absolutely no consistency shown with the results of this device.

Test 6
As one final test, several hours later, I tested the eLogger V4 with brushless rpm Sensor attached, on my workbench in the basement, and got the following results. Voltmeter through the whole capture, 18.10 volts. eLogger 18.09 volts and 0.24 amps through the whole test. Again, there was NO load on the eLogger and the amps came back! There was only one spurious 17 RPM captured through the capture time.
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Mar 07, 2013, 08:59 PM
billpa's Avatar
Hi Ken,

Sorry you're having an issue. I just grabbed an eLogger from our inventory and ran logs for a few minutes each with a power supply set to around 20V, and also ran a live mode test at the same voltage. The internal voltage resolution of the elogger is approximately 0.02V, so fluctuation of that resolution was seen (and is normal). However, I didn't see any deviation from 0 amps, nor any further deviation of the voltage. This was with a factory calibrated logger at 10 hz sample rate, running the firmware in our 10.44 software. I did not connect a brushless sensor available for this test, though (that certainly should not affect the results).

The fact that your voltage and current is varying considerably, and dropping to 0 volts sometimes, suggests to me that there is either something wrong with your eLogger, or there's some issue manifesting with your particular logging settings, or some issue that is manifesting after user calibration.

I'd recommend this to help narrow it down:
- Please reset calibration to factory settings, switch to 10Hz logging and no brushless sensor (log only volts and amps)
- If you still see issues with the logging, I think we can confirm we'll need to replace your logger
- If you don't see issues, we'll need to drill down on what particular setting is causing the issue.
Mar 08, 2013, 09:20 AM
Registered User
Ken Myers's Avatar
I should have given a few more details.
I have the e-Logger V4 with Wire Leads - I use Anderson Power Poles (APP connectors)
It is the 100 amp version
Software version 10.44
Firmware version 1.21
As mentioned, I had rezeroed the amps several times.
I also had “calibrated” the volts.
Capture rate was set to 2 samples per second to match my Emeter 2 RDU and Ice 50 settings.

I reset the capture rate to 10 samples per second.
I reset the voltage and current to Factory Defaults
The brushless rpm Sensor was disconnected

Voltmeter attached to pins in battery lead
6 different data collections of approximately 10 seconds with one minute wait between each collection.
Sample 1 voltmeter steady 18.08v, eLogger V4 18.17v dropping to 18.13v with some 18.15v mixed in and 0.18 amps

Sample 2 voltmeter started at 18.08v and dropped to 18.07v, eLogger V4 steady 18.17v and 0 amps

Sample 3 voltmeter started at 18.07 and dropped to 18.06, eLogger V4 started at 18.15 and dropped to 18.08 with some 18.10 and 18.13 in-between and constant 0.12 amps recorded

Sample 4 voltmeter started at 18.06 and dropped to 18.05, eLogger V4 constant 18.17v and 0 amps

Sample 5 voltmeter steady 18.05, eLogger V4 started 18.10v and dropped to 18.08v with readings mixed through capture, a majority of 0.12 amp captures but some captures showed 0.0 amps.

Sample 6 voltmeter started at 18.05 and dropped to 18.03, eLogger V4 steady 18.08v and mostly 0.12 amps with a few 0.0 amps near the end of the sample capture.

Remember that there was approximately a one minute wait period between each session. Use my kitchen timer.
Since I use a Mac as my main computer, each session was saved, transferred to the Mac and opened in a spreadsheet for viewing of all six of the sample sessions.

By the way, there must be an extra space between the GForceX*100 and GForceY*100 notations as the header columns are off by one column starting at column L when opened in a spreadsheet.

I have the .FDR session files available as well as a spreadsheet in .xls format with each session on its own sheet.

Mar 08, 2013, 01:12 PM
billpa's Avatar
Thanks, Ken, for doing these additional tests. I am not sure what is causing that level of variation. But, I think our best course of action is to replace your eLogger, to eliminate a potential hardware failure.

If you could open a ticket with us at and reference this thread, we'll send you a replacement.
Mar 08, 2013, 02:11 PM
Registered User
Ken Myers's Avatar
Thanks so much for the very quick response. I opened a support ticket and provided a link to this thread and my personal information.

Would you like this one back to check it out?

Thanks so much,
Mar 09, 2013, 12:18 PM
billpa's Avatar
Hi Ken,

Thanks. Yes, we'll be asking for that back in the ticket process.
Mar 11, 2013, 11:47 AM
Registered User
Ken Myers's Avatar

The complete eLogger V4 w/leads and my APP connectors was mailed from the Walled Lake, MI 48390 post office this morning at 9:27 a.m. All items including the CD, USB lead, throttle Y, and paper accompany the package were included. Also included was a copy of the support request email with my mailing address written on it and a copy of the invoice from Tower Hobbies.

Thank you,
Ken Myers
Last edited by Ken Myers; Mar 11, 2013 at 07:07 PM.
Mar 13, 2013, 07:26 PM
Registered User
Ken Myers's Avatar
I received a message from Support that my faulty eLogger arrived at Eagle Tree today.
Mar 15, 2013, 07:35 AM
Registered User
Ken Myers's Avatar
Thought I might have gotten a message yesterday, Thursday, March 14, that the replacement had been shipped since the faulty one arrived on Wednesday.
Mar 15, 2013, 05:16 PM
billpa's Avatar
Hi Ken, we've received the eLogger, and are setting up a repro today to attempt to duplicate the issue. The hope is that we're able to duplicate, which means the new logger should address it. We'll update the ticket status with results.
Mar 19, 2013, 06:45 AM
Registered User
Ken Myers's Avatar
I received the following from Eagle Tree Support, yesterday, March 18.

"Hello Mr. Myers,

We were able to reproduce a small variation in the reported voltage at startup with your returned eLogger unit, but no variation in amperage.

We're preparing a replacement unit for shipment to you tomorrow via USPS airmail. If you have any problems with the replacement unit we'll investigate further."

As I noted, I do have the files that show amps when there is no load on the meter. They are inconsistent and fluctuate sometimes.

Looks like the replacement is to be shipped today, March 19, the seventh day after receiving the faulty unit.
Mar 21, 2013, 05:07 PM
Registered User
Ken Myers's Avatar
The replacement came in the mail today. I won't have time to do anything with it until tomorrow morning. Got my fingers crossed.
Apr 06, 2013, 11:05 AM
Registered User
Ken Myers's Avatar
Hi Bill,

It was a pleasure meeting you at Toledo on Friday, April 5.

I've had a chance to do some testing with the new unit. At the moment it appears to be okay, but I'm still having a problem calibrating the volts.

When the data is placed into a spreadsheet, I found that the headings in row 19 skip column L. (See screen capture.) Therefore the RPM data is in column Q Temp3*10 (13106) instead of column R RPM.

This occurs in the Open Office spreadsheet and in Microsoft Excel, both used on a Mac.
Apr 06, 2013, 12:14 PM
Registered User
Ken Myers's Avatar

Voltage calibration problem demonstrated

Here is the voltage calibration problem.

The photo titled 7v is a 2S ďA123Ē 2300mAh pack, 14v is a 4S ďA123Ē 2300mAh pack and 37v is a 10S ďA123Ē 2300mAh pack.

There is no load on the eLogger V4, just the battery pack hooked up to it.

The multimeter is a Radio Shack Digital Multimeter Cat. No. 22-168A.

The order of the readings were 10S, 2S, 4S.
Apr 09, 2013, 09:24 PM
billpa's Avatar
Hi Ken,

Enjoyed speaking with you at Toledo also! Regarding the issue with OpenOffice viewing of .FDR files, sure enough, you are correct that an extra space is introduced in the data legend. At least on my version of Excel here on a PC this extra space is ignored, but apparently it is not ignored on the Mac. The space has been removed, and this will be part of the next software update we do.

Regarding the intermittent voltage display issue you are seeing above, I have a theory as to what may be causing this. I have reserved some time next week to look more deeply into that, and will get back with you then.

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