Fun, Learning, Friendship and Mutual Respect START  HERE


Unregistered
Go Back   HeliFreak > R/C Electronics Support > MSH Brain FBL Unit


MSH Brain FBL Unit MSH Brain Support Forum


Like Tree5Likes
Reply
 
LinkBack Thread Tools Display Modes
Old 03-26-2017, 10:04 AM   #1 (permalink)
Registered Users
 

Join Date: Feb 2017
Default Mah correction factor

OK so just a little help needed please guys.
Finally got the first couple of flights on the first heli iv swapped over.

Can anyone tell me the sum I need to work out the percentage I need to increase or decrease the mah consumed by?

Is it normal to see a difference in accuracy against different c rated packs?

Opti 30c I got, 2999 mah consumed in tx, 3291 mah put back in by my pl6, so 292mah difference

Opti 50c I saw 3749 mah consumed, and 3929 mah put back. So only 180mah difference

Cheers all
Dan. is offline        Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
Old 03-26-2017, 10:16 AM   #2 (permalink)
Registered Users
 
Posts: 11,022
 

Join Date: Sep 2008
Location: Atlanta, GA
Default

Quote:
Originally Posted by Dan. View Post
OK so just a little help needed please guys.
Finally got the first couple of flights on the first heli iv swapped over.

Can anyone tell me the sum I need to work out the percentage I need to increase or decrease the mah consumed by?

Is it normal to see a difference in accuracy against different c rated packs?

Opti 30c I got, 2999 mah consumed in tx, 3291 mah put back in by my pl6, so 292mah difference

Opti 50c I saw 3749 mah consumed, and 3929 mah put back. So only 180mah difference

Cheers all
Your 30C flight was under reported by 9% vs the actual, so you would need to raise the correction factor in the software to +9% (2999/3291=0.91 so 9% too low)

The 50C flight was only 5%. Were both flights exactly the same RPM and flight style? Are both packs the same age, or could the 50C pack not really be providing the claimed current handling ability?

Its normal for the reported values to be further off from the actual values the less current you are pulling, so you may find that higher head speeds and more agressive flight gets closer to actual values. The same could be said of tired packs that sag in voltage causing more current to be pulled for the exact same moves on a better pack.

I see the same thing switching between 12S and 14S. My 14S flights will be off by a larger margin because Im pulling less amps for the same flight style. My 12S setup was within 11 mAh of what was placed back during charging, so practically dead on!

In your case I would just use the 9% correction value for now until you can get a few more flights to know for sure where things settle. This will still get your 50C pack within 4%, but 4% on the over reported side rather than under reported which is the safer side to be on
__________________
Tony
Synergy 516, Gaui R-5 Speed, Cypher Vtol Jet, Spirit FBL, Hobbywing and Scorpion Tribunus ESC, Xnova motors. The girl in my DX9 tells them all what to do

Last edited by Xrayted; 03-26-2017 at 10:27 AM..
Xrayted is offline        Reply With Quote Quick reply to this message
Old 03-26-2017, 10:41 AM   #3 (permalink)
Registered Users
Thread Starter Thread Starter
 

Join Date: Feb 2017
Default

Awesome buddy thank you!!
No it is easily possible I spent longer in iu2 on the 50c flight as it was my last of the day, the wind was also abit too much as the afternoon went on yesterday. According to the logs I pulled 250 amps on that last flight!

Both flight packs were bought new, at the same time towards the end of last year and have had the same amount of flights
Dan. is offline        Reply With Quote Quick reply to this message
Old 03-26-2017, 10:48 AM   #4 (permalink)
Registered Users
 
Posts: 11,022
 

Join Date: Sep 2008
Location: Atlanta, GA
Default

Quote:
Originally Posted by Dan. View Post
Awesome buddy thank you!!
No it is easily possible I spent longer in iu2 on the 50c flight as it was my last of the day, the wind was also abit too much as the afternoon went on yesterday. According to the logs I pulled 250 amps on that last flight!

Both flight packs were bought new, at the same time towards the end of last year and have had the same amount of flights
Yes, just calibrate for the pack that is farthest off for now until you can get several more flights in and see what the actual average error turns out to be. You will likely end up fine tuning the error a couple times before settling in on something that works for everything.

You want some padding to be in the alarm values anyway so you have time to land without dragging the packs too low.
__________________
Tony
Synergy 516, Gaui R-5 Speed, Cypher Vtol Jet, Spirit FBL, Hobbywing and Scorpion Tribunus ESC, Xnova motors. The girl in my DX9 tells them all what to do
Xrayted is offline        Reply With Quote Quick reply to this message
Old 03-26-2017, 11:53 AM   #5 (permalink)
HF Support
 
Posts: 41,332
 
My HF Map location
Join Date: Jul 2007
Default

I wonder how useful it is to base mAh consumed off mAh put back in for the purposes of calibrating the Brain2's mAh reading. You're relying on the charger to be accurate and your cells to be well balanced.
TheBum is offline        Reply With Quote Quick reply to this message
Old 03-26-2017, 12:08 PM   #6 (permalink)
Registered Users
Thread Starter Thread Starter
 

Join Date: Feb 2017
Default

Quote:
Originally Posted by Xrayted View Post
Yes, just calibrate for the pack that is farthest off for now until you can get several more flights in and see what the actual average error turns out to be. You will likely end up fine tuning the error a couple times before settling in on something that works for everything.

You want some padding to be in the alarm values anyway so you have time to land without dragging the packs too low.
Awesome, I do have a 3rd pack iv not had chance to get back on the charger yet. This is a zippy flight pack, same age but definitely a lesser quality. I will get these recharged this evening so I can check the values againt the others!


Unrelated but there are several points in each flight that main rotor rpm drops to 1000rpm randomly for a split second, at no point during each flight did I notice any substantial drop in headspeed!
Dan. is offline        Reply With Quote Quick reply to this message
Old 03-26-2017, 12:13 PM   #7 (permalink)
Registered Users
 
Posts: 19,212
 

Join Date: Jan 2009
Location: NorCal
Default

Most important thing is to verify resting voltage of cells is around 3,75 aftery flight. Precise mah doesn't actually matter. The alarm just needs to be at the right value.
__________________
Xpert
OnTheSnap is offline        Reply With Quote Quick reply to this message
Old 03-26-2017, 12:48 PM   #8 (permalink)
Registered Users
 
Posts: 3,752
 

Join Date: Feb 2012
Location: Chilliwack, British Columbia
Default

Quote:
Originally Posted by OnTheSnap View Post
Most important thing is to verify resting voltage of cells is around 3,75 aftery flight. Precise mah doesn't actually matter. The alarm just needs to be at the right value.
+1

This is how we should be thinking about mAh consumption values
__________________
HELIDIRECT - IKON - HOBBYWING - XNOVA - XPERT - PULSE - ROTOR TECH
Colin Broughton is offline        Reply With Quote Quick reply to this message
Old 03-26-2017, 05:09 PM   #9 (permalink)
Registered Users
 
Posts: 156
 

Join Date: Mar 2015
Default

Quote:
Originally Posted by Colin Broughton View Post
+1

This is how we should be thinking about mAh consumption values
Agree, I focus on to get a value matching 3,75 resting. Will mention though, on one my Castle (Lite50-Oxy3) I ended up on 13%, on the other (CC Lite100-G380) 50% is not enough. If I measure the mAh I consume and put back I would end up at 55% or so. But 50 is the limit in the setup.
Gscott likes this.
__________________
OXY5 | Goblin 500/700 | Jeti & Brain
desmofred is offline        Reply With Quote Quick reply to this message
Old 03-27-2017, 09:18 AM   #10 (permalink)
Registered Users
 
Posts: 2,019
 

Join Date: Nov 2010
Default

Quote:
Originally Posted by OnTheSnap View Post
Most important thing is to verify resting voltage of cells is around 3,75 aftery flight. Precise mah doesn't actually matter. The alarm just needs to be at the right value.
Ok, When the voltage needs to be measured,?

Inmediatly after the heli land or after some minutes ?

TIA
__________________
Align 800e PRO DFC // KRAKEN Yellow // Align 700N DFC, 105HZ-R HV // Goblin 700Comp // 2x Goblin 420 // RealFlight 7.5 // neXt // AccuRc // Tribunus - Vbar Control Touch - Vbar Neo
msallua is offline        Reply With Quote Quick reply to this message
Old 03-27-2017, 10:59 AM   #11 (permalink)
Registered Users
 
Posts: 3,637
 

Join Date: Nov 2012
Default

Quote:
Originally Posted by Dan. View Post
...

Unrelated but there are several points in each flight that main rotor rpm drops to 1000rpm randomly for a split second, at no point during each flight did I notice any substantial drop in headspeed!
The rpm logged is raw meaning any inconsistencies are shown. I see that rpm dropout on all 3 of my helis with different escs. Only 1-3 times per flight.

It does not affect the gov in flight. If you are seeing it a lot then maybe think about rerouting your rpm wire.
__________________
Protos Max Leggero 700, Logo 600SE, Blade 230s
DX9
flint723 is offline        Reply With Quote Quick reply to this message
Old 03-27-2017, 11:02 AM   #12 (permalink)
Registered Users
 
Posts: 19,212
 

Join Date: Jan 2009
Location: NorCal
Default

Quote:
Originally Posted by msallua View Post
Ok, When the voltage needs to be measured,?

Inmediatly after the heli land or after some minutes ?

TIA
Recovers a little after landing. But I just check when I land with telemetry. On 12s my target is 44.5V -45V right when I land. .
__________________
Xpert
OnTheSnap is offline        Reply With Quote Quick reply to this message
Old 06-04-2017, 08:21 PM   #13 (permalink)
Registered Users
 
Posts: 2,324
 

Join Date: Feb 2013
Location: Perth, Western Australia (the most isolated (AND COVID FREE!) capital city on earth!)
Default

I'm flying 2 x 5000 mAh 6S batteries on the Protos Leggero (in 2 sticks - so 4 packs). Charger reports approx 6400 mAh (for each stick). Brain2 with HW 130A reports 3200 mAh. The ratio over several flights with both sticks is Charger reports 2.02 x Brain.

I would have expected to set the mAh Correction Factor % to 100 (%). That is "Show double what you are reading from the HW). Have I understood that correctly? If so, why is the slider maxed out at 50?

Or should I read it as "The HW is showing only 50% of the value, so double it"? And consequently, the slider at 50 is the correct instruction.

TIA,
Paolo
__________________
XLPower 700, ALIGN 550L (beater), Prôtos MAX V2 Leggero 700 & Evoluzione 800 (RCHN #803 - joined just before they shut up shop!)
PaoloFCantoni is offline        Reply With Quote Quick reply to this message
Old 06-04-2017, 09:13 PM   #14 (permalink)
Registered Users
 
Posts: 3,637
 

Join Date: Nov 2012
Default

That is normal, your charger is reporting double because you are charging at 6s not 12s. Brain is reporting mah consumed at 12s voltage.

Seems confusing but if you convert to watt/hours, 6.4 a/h at 22.2v is the same as 3.2 a/h at 44.4v.

It seems your Mah reporting is pretty much dead on.
__________________
Protos Max Leggero 700, Logo 600SE, Blade 230s
DX9
flint723 is offline        Reply With Quote Quick reply to this message
Old 06-05-2017, 08:31 AM   #15 (permalink)
Registered Users
 
Posts: 2,324
 

Join Date: Feb 2013
Location: Perth, Western Australia (the most isolated (AND COVID FREE!) capital city on earth!)
Default

Quote:
Originally Posted by flint723 View Post
That is normal, your charger is reporting double because you are charging at 6s not 12s. Brain is reporting mah consumed at 12s voltage.

Seems confusing but if you convert to watt/hours, 6.4 a/h at 22.2v is the same as 3.2 a/h at 44.4v.

It seems your Mah reporting is pretty much dead on.
Cool! That's good to know! (Once you know! )

Paolo
__________________
XLPower 700, ALIGN 550L (beater), Prôtos MAX V2 Leggero 700 & Evoluzione 800 (RCHN #803 - joined just before they shut up shop!)
PaoloFCantoni is offline        Reply With Quote Quick reply to this message
Old 06-05-2017, 11:38 AM   #16 (permalink)
HF Support
 
Posts: 41,332
 
My HF Map location
Join Date: Jul 2007
Default

That got me too when I first started using mAh telemetry...and I have a EE degree, so I should have known better.
__________________
Alan (just call me "Bum"; no need to be so formal)
HeliFreak Support
Protos Max Evo 700 (Brain 2), Protos Max V2 770 (iKON 2), Synergy 516 (Brain 2), Oxy 2 (Falcon 12)
Graupner MZ-32

Experience is something you gain only after you need it.
I wouldn't mind social media so much if it didn't involve people.
TheBum is offline        Reply With Quote Quick reply to this message
Old 06-05-2017, 05:49 PM   #17 (permalink)
Registered Users
 
Posts: 2,324
 

Join Date: Feb 2013
Location: Perth, Western Australia (the most isolated (AND COVID FREE!) capital city on earth!)
Default

Quote:
Originally Posted by TheBum View Post
That got me too when I first started using mAh telemetry...and I have a EE degree, so I should have known better.
As do I! An object lesson perhaps?

Paolo
__________________
XLPower 700, ALIGN 550L (beater), Prôtos MAX V2 Leggero 700 & Evoluzione 800 (RCHN #803 - joined just before they shut up shop!)
PaoloFCantoni is offline        Reply With Quote Quick reply to this message
Old 06-08-2017, 12:43 AM   #18 (permalink)
Registered Users
 
Posts: 2,923
 

Join Date: Jun 2005
Default

Quote:
Originally Posted by Dan. View Post
Opti 30c I got, 2999 mah consumed in tx, 3291 mah put back in by my pl6, so 292mah difference

Opti 50c I saw 3749 mah consumed, and 3929 mah put back. So only 180mah difference

Cheers all
Question . . . . . .

Depending on the charger and how it balances the cells at the end of the charge will it not be normal to "APPEAR" to be putting more mah back in then used. This is due to the face that the changer will discharge and recharge cells to balance the pack?
__________________
Rudy - Currently in ??? It depends on the day of the week where I am

We had a great country once. You know what made it great? “I can.” Then the weak came along, “the I cant’s” and destroyed it.
Rudy is offline        Reply With Quote Quick reply to this message
Old 06-08-2017, 01:18 AM   #19 (permalink)
Registered Users
 
Posts: 3,637
 

Join Date: Nov 2012
Default

Quote:
Originally Posted by Rudy View Post
Question . . . . . .

Depending on the charger and how it balances the cells at the end of the charge will it not be normal to "APPEAR" to be putting more mah back in then used. This is due to the face that the changer will discharge and recharge cells to balance the pack?
Depends on how sophisticated the charger is, and the state of the packs. Well matched cells will not need much balancing.
__________________
Protos Max Leggero 700, Logo 600SE, Blade 230s
DX9
flint723 is offline        Reply With Quote Quick reply to this message
Old 06-08-2017, 09:16 AM   #20 (permalink)
HF Support
 
Posts: 41,332
 
My HF Map location
Join Date: Jul 2007
Default

In general, any extra balancing will result in excessive mAh being reported. That said, a charger could offset that by measuring mAh on the balance ports, but that would add considerable expense for something that’s not critical.
TheBum is offline        Reply With Quote Quick reply to this message
Reply




Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the HeliFreak forums, you must first register.
Please enter your desired user name, your REAL and WORKING email address and other required details in the form below.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself. Use a real email address or you will not be granted access to the site. Thank you.
Email Address:
Location
Where do you live? ie: Country, State, City or General Geographic Location please.
Name and Lastname
Enter name and last name here. (This information is not shown to the general public. Optional)
Helicopter #1
Enter Helicopter #1 type and equipment.
Helicopter #2
Enter Helicopter #2 type and equipment.
Helicopter #3
Enter Helicopter #3 type and equipment.
Helicopter #4
Enter Helicopter #4 type and equipment.

Log-in


Thread Tools
Display Modes

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On




Copyright © Website Acquisitions Inc. All rights reserved.
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2020 DragonByte Technologies Ltd.

SEO by vBSEO 3.6.1