Finally got me an Eagletree Data Logger! - RC-Monster Forums

sikeston34m · **Finally got me an Eagletree Data Logger! -** 12.26.2009, 10:43 PM

Well I finally got me an Eagletree Data Logger!

I made a run with my E Revo with Medusa Setup and my V2 Monster finally bit the dust!

So it was time to change the entire setup around.

This setup is one of the old HV4400 Maxx sensored Motors upgraded with the Sintered Rotor w/5mm shaft.

I have no idea what top speed this is geared for. LOL

It is geared 14/52 using Mod 1 gears.

ESC of choice is the MM Pro! It does have some power handling ability

Power Supply is a pair of Turnigy 4S 20C 4000mah wired parallel.

Just a few short bursts on the graph. It's dark here, but I'll get some good graphs tomorrow.

Ever seen a 4S setup hold 3.91 volts per cell under a 108 amp Load?

There is MUCH experimenting to be done!

Check this out!

magman · 12.26.2009, 10:49 PM

pretty cool...keep the updates coming. I am thinking of getting a data logger in the spring, so I will be watching your results closely

simplechamp · 03:31 AM

Looks like the Turnigy cells hold up well under load. I'd like to see the numbers a bit later in the run as well.

An EagleTree is next on my gadget list too.

phildogg · 12.27.2009, 11:10 AM

I have been playing with mine and love it. The turnigy lipo's hold a load well.
phil

sikeston34m · 12.27.2009, 12:30 PM

Ok, here's a better run. Same Setup.

The two 4S packs of 4000mah Turnigy is what I want to use with a 8S HV setup. When I can locate a HV ESC that is.

I think they would do well.

sikeston34m · 12.27.2009, 02:09 PM

Just logged another short run on 4S 30C 5000mah Turnigy Packs.

Looks like they hold 3.635 volts under a 109 amp load.

This is going to be interesting to compare how different packs hold voltage under a load.

I have alot of different packs to put through the testing.

Having fun here. Feel free to comment.

BrianG · 12.27.2009, 02:27 PM

Before you get too far, you should calibrate the current and voltage measurements so that you start out with a good baseline. There are two areas; zero and actual values. Zeroing just makes sure 0v and 0A is really 0v and 0A. Calibrating the non-zero values is a little more complex. First, you have to come up with a dummy load that you hook to your packs which will draw around 10A. Hook the load to the pack along with the ET. Measure the voltage and current with a multimeter. Then, see what ET is saying the values are. If different, there is a screen where you can enter the real vs displayed values.

sikeston34m · 12.27.2009, 02:43 PM

Quote:

Originally Posted by BrianG

Before you get too far, you should calibrate the current and voltage measurements so that you start out with a good baseline. There are two areas; zero and actual values. Zeroing just makes sure 0v and 0A is really 0v and 0A. Calibrating the non-zero values is a little more complex. First, you have to come up with a dummy load that you hook to your packs which will draw around 10A. Hook the load to the pack along with the ET. Measure the voltage and current with a multimeter. Then, see what ET is saying the values are. If different, there is a screen where you can enter the real vs displayed values.

Hi Brian,

I did calibrate the displayed voltage.

To calibrate the Amp load display is gonna take a little more work.

I have an outrunner motor spinning an 11 inch prop. This is rigged up to be a fan. The thing really puts out huge amounts of air too. LOL

Powering the "fan" is a Mamba Max ESC hooked up to a servo tester. The servo tester controls the "variable speed" of the fan.

I hook my multimeter in line, along with the Eagletree, to get the 10 amp load. Then calibrate Amps with that.

Hmmm...........gonna have to look at my wiring situation.

Do you think the factory amp calibration will be that far off?

sikeston34m · 12.27.2009, 03:34 PM

Ok, I just did a run on 4S 20C 5000mah Turnigy Lipo.

If you compare this graph with the 30C graph above, you will see they are the same!

The numbers are the same. The 20C and the 30C packs are built with the same cell.

I always suspected this.

The 30C is holding 3.635 volts per cell under a 109 amp load

The 20C is holding 3.652 volts per cell under a 108 amp load

sikeston34m · 04:47 PM

Next up are some packs nearing the end of their useable life.

We've graphed some good packs, now let's do some not so good packs.

Flightpower are some GREAT packs IMO, the packs in these graphs are dying of old age AND have many cycles on them.

They are 4S 3200mah 30C packs, two of them parallel for 6400mah.

2.97 volts per cell under 108 amp load. Not good, considering the run only lasted 12 minutes to the LVC.

These might be ok for a few more cycles in something like a Rustler maybe, but they now need to be retired from MT use IMO.

sikeston34m · 12.27.2009, 04:46 PM

Next up is the end of the run that shows the Truck getting on the LVC.

The LVC is set at 3.2 volts per cell.

This graph shows some interesting behavior of the LVC. It appears the LVC does have a reaction time.

This is shown where the low pack volts are 10.93

That is 2.73 volts per cell. Hmm........

Once the LVC reacts, it is "regulating" amp draw and hold the LVC to around 12.8 volts. Right where it should be.

Interesting.

crazyjr · 12.28.2009, 02:50 AM

Mine hit 124 amps on the highest graph i have, This was a MGM 16025 and a lehner 2250 in a twin force with 6s lipo's. This was the 100 amp eagle tree micro
[IMG]

[/IMG]

sikeston34m · 12.31.2009, 08:59 PM

I noticed the 100 amp version is pegging out on amps alot as I log different setups.

Thinking about getting the 150 amp verison.

Are the Wire leads any bigger on the 150 amp version?

The leads on the 100 amp version appear to be 14 Ga. Barely Big enough IMO.

phildogg · 12.31.2009, 09:04 PM

Mine look like 12g on the 150a.
phil

BrianG · 12.31.2009, 09:25 PM

These loggers do log higher than their rating, but I strongly suspect they lose accuracy/linearity much beyond the rating. If you zoom in on a ~120A peak, you will probably see the slop estart to round off. That's not typical if you look at the peaks under the 100A rating. So, the real peaks are probably much higher than you think they are if you extrapolate the curve. Also, if you calculate cell resistance over various current draws, you will be able to get an idea of the real current and see if it matches the graph.

I've logged over 140A peaks on a CRT.5 using a Medusa 36-50-3300 on 3s geared fairly conservatively. So I imagine the peaks on the 8th scales are well into the 200-300A range.

Oh, and my 150A version uses 12GA wire from what I can tell.