trilerian

iTrader: (51)

Using the ACS758-200U. Mouser didn't have the 772 in stock, so I just got the 758. But still a unidirectional 200A sensor. I haven't started to troubleshoot the first couple of seconds that looks saturated. However, the 200A will go slightly over 200A, so saturated should be 210-220A. The reason why I left it there, look at the RPM vs Current. Notice the RPM is only going up to 17000 RPM. This is not correct, so MiniPro is working on a software update for me. I am waiting on that update before I do anymore testing.

kufman

iTrader: (6)

I couldn't quite read the part number on the device but I thought you were getting the higher current device. I thought it might have been the 100A version since that is what I have and it saturates around 120A. My other thought is maybe the software is drawing a linear line for where it doesn't have data? That is, the first RPM reading occurs at 1000+ rpm so the software just assumes that the current was flat from 1000 rpm back to 0 rpm?

trilerian

iTrader: (51)

The software doesn’t extrapolate back to 0 time. It generally starts picking up data after 500ms, and you will see the sharp increase. I say generally, as sometimes you get random data in the first few tenths and sometimes a straight line.

That said, this rpm for this at least is not accurate. I think this was a 13.5 and the rpm should be double. Minipro is working on it. This is their v3 board and has some bugs still.

kufman

iTrader: (6)

Motor dynos also work as battery dynos. HooVoo 5000 vs a GensAce 5100. Both charged to storage before the first pulls. First pull on the Gens Ace got messed up so I plotted runs 2 and 3 for both packs. All 3 runs were done back to back without being brought back up to storage voltage. The test setup was pretty gentle since it was just a Novak 25.5 with 30 degrees of timing being run on a Castle Mamba X.

Sabin

iTrader: (1)

First things' first - Thank you very much for building me one of these sensor boards. I'm sure with that I can help corroborate your findings for 17.5 motors.

The only one I have is an older MuchMore Fleta 17.5, but it will be coupled with near brand-new EA Motorsports' 6000mah packs.



I noticed that aswell. So I made a small change in when it starts to log data. From zero to two seconds in, I have it logging data when the motor is turning at 20%.

kufman

iTrader: (6)

How do you determine 20%?

trilerian

iTrader: (51)

Custom throttle profile. You can set throttle percentage and for how long, and whether or not you want it to log. So probably sets a 20% initial for 1 second with no logging, then full throttle with logging.

Sabin

iTrader: (1)

I found it's better to create two instances in the throttle profile for that. Two seconds at 20% unlogged to have the motor settle, two seconds at 20% logged to start data streaming before a full pull.

StephenR

iTrader: (1)

The following motors have been tested and uploaded:
Tekin G4 SPEC-R2 Elite (253w @ 50 degrees)
Exalt Phoenix Gold (237w @ 40 degrees)
Team Scream Racing T-1 The1 (243w @ 44 degrees)
Motiv MC5 (249w @ 50 degrees)

Also my XFactor motor was tested at 30, 35, 40, 45, 50 degrees to compare the new Justock G3 esc to the old version to make sure there are minimal differences.

kufman

iTrader: (6)

What voltage? Full 2s?

StephenR

iTrader: (1)

8.44v. The same as all the previous motors tested.

kufman

iTrader: (6)

Battery or power supply?

StephenR

iTrader: (1)

battery

gigaplex

iTrader: (2)

Battery voltage is not stable under load at 8.44V, it's going to lead to variable results. I'd recommend using 7.8 as the discharge curve is much flatter. And why 8.44? That's over the maximum charge limits of the major racing regulatory bodies.
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Sabin

iTrader: (1)

All these discharge graphs absolutely debunk your claim that battery voltage is unstable under testing.

https://www.rcgroups.com/forums/thum...=threadgallery

Whether a pack is 2s, 4s, or 6s doesn't matter - the cells show they have a stable discharge curve and are suitable for testing for any ones' needs. The only thing that differentiates them is which brand they are. They show various constant loads, anywhere from 75 amps to 150 amps.

If you have better data, then show us your results. Show us the instability. Show us the faults. Show how you arrived at your claim.