Eagletree mystery for the Guru's - RC-Monster Forums

crazyjr · **Eagletree mystery for the Guru's -** 01.26.2007, 07:48 PM

I got my Eagle tree Micro power E-logger today, I got it set up and hooked it into My Gmaxx/7XL/Mamba Max/5s Lipo combo to test and see how it would work. I ran it about a minute and went to download the info. Upon downloading and looking over the data, I noticed a peculiar spot in the data-logging. At 55.0 to 55.4 seconds the pack voltage jumped to 32 volts While it was pulling over 120amps. I'm not for sure what happened but for a split second it pulled over 5hp (max wattage was 4083) and nothing smoked, even run it after and nothing was amiss. Was it a glitch or did it really happen? the eagletree was close to motor and UBEC if that could have been what caused it. I'm not sure how to put the graph on here but anybody who wants to see the file I can Email you the file and let you see for yourself and draw your own conclusions. PM me you Email and i'll send it to you
thanks

MetalMan · 01.26.2007, 07:53 PM

I think that happened to me once before, too. Most likely it's just a glitch, but I don't think it's due to it being close to the motor/UBEC.

crazyjr · 08:16 PM

Ok i figured that, because i didn't see anywhere, during the run where it would indicate the power it showed (also didn't bust the stock Emaxx diffs), also the packs didn't sweel or feel hot and i know, if it got there, the MM probably would have smoked real good. Except for that spot, the test went good and i saw that the combo was pulling over 1900watts at a couple points (not bad for a $140 esc)

pinolelst · 01.26.2007, 09:08 PM

I see on eagle trees site that the micro logger will log "100 amps +-" and am curious how high it does really register.I already have the dashboard that I use for my aircraft altitude and airspeed and like the idea of logging power data as well.
thanks in advance

pinolelst

crazyjr · 01.26.2007, 09:56 PM

Mine shows 130 and on a couple real hard spots i got over 120amps on it, I wouldn't want to run real long at that level long, not sure what would happen

Serum · 01.27.2007, 03:55 AM

It can show much higer peaks that 100A pinolest.

Crazy, it must be a glitch.. what cells did you used on the 7XL? i know the 7XL on 5S is a hot setup.. it runs like crazy.. :)

phildogg · 01.27.2007, 09:50 AM

one question about the eagletree. I'm running 2 2s packs I just install the eagletree inline with one pack right? thanx bros.
phil

crazyjr · 12:06 PM

Serum,I'm running maxamps 8000mah in 2s and 3s packs

phildogg, If you are running a Gmaxx/G2R setup and running series just plug in the esc to the female deans plug and the end of the series connector from the batteries to the male plug (just like if you just plug in the batteries to the esc)

phildogg · 01.27.2007, 12:46 PM

but that would only moniter one battery is that what you means? on my esc I have 2 deans now connected in series. 1 male for each batt.. on a E-maxx. just plug in inbetween one batt? I don't yet have one but will soon and have been wondering about this.
phil

crazyjr · 01.27.2007, 01:37 PM

In that case you might have to monitro one battery and double the numbers, I'd ask eagletree about that

BrianG · 01.27.2007, 02:59 PM

Quote:

Originally Posted by crazyjr

In that case you might have to monitro one battery and double the numbers, I'd ask eagletree about that

If connecting the Eagletree on one set of batts in a series set, just double the voltage numbers, not the current numbers. ;)

crazyjr · 01.27.2007, 06:13 PM

Thanks wasn't sure how it worked

phildogg · 01.27.2007, 06:25 PM

how is your esc/ batts hooked up crazy?
phil

crazyjr · 01.27.2007, 07:51 PM

I got a mamba max with a single deans and a series connector for the batteries

BrianG · 01.27.2007, 08:48 PM

Quote:

Originally Posted by crazyjr

Thanks wasn't sure how it worked

Jusdging by the fact it has an input and output connector, the eagletree most likely measures current by placing a very small precision resistance in series with the load, something like 0.001 ohms. Then it measures the voltage drop across this tiny resistance and calculates the current. So, let's say it is a 0.001 ohm shunt, and you are drawing 100A, it would have 0.1v dropped across it. They keep it small so it has little effect on the overall voltage. Then, it measures the voltage like any normal voltmeter would.

So, if you put it inline with only one pack, it will measure half the full system voltage, but the current will be right (current is the same in a series circuit). Obviously, this will also affect your power readings. Just multiply the power by two as well...