• This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn more.

Intermittent pulsing as I throttle up

#1
I bought power pack A and the mini corsair build a few weeks back. Just finished the whole project. Immediately running into a similar problem that I saw someone else hit with Power Pack C on another thread. They posted this youtube video which shows my exact problem. The build is all straight "out of the box" stuff from Flite Test. I'm new to the hobby so I'm not customizing or anything yet.

I didn't see an exact resolution on that thread or things to really try. Just hoping to get some troubleshooting ideas.

So far, I've:
  1. Ensured battery is fully charged
  2. Re-calibrated the ESC with transmitter throttle range.
  3. Checked the motor connections to the ESC.
  4. Check connections to the transmitted for ESC
Other ideas?
 

FDS

Well-known member
#2
Check the battery cell voltage, especially as you apply throttle. Put a good lipo checker on the balance lead, read the cell voltages, they should be within 0.1v at least of each other at rest, if one cell is a lot below the others then that’s the problem, you need to balance the pack. Put it on the charger at 1c in BALANCE charge, with both leads connected to the charger, then try again.
If the cells are close, next check the voltage of the whole pack under load. TAKE THE PROP OFF and see what happens to the overall pack voltage as you apply the throttle, if it nosedives quickly then your battery cannot cope with the current demands of the motor. Generally I never use any pack under 40c for my planes, that way there’s head room. Also the actual discharge vs claimed can be off.
What the pulsing might be is the over discharge protection on the ESC, this is usually activated when cell voltage goes below 3.6v per cell, the esc pulses to warn you or reduces throttle, depending on the type. If your battery is faulty, unbalanced or not powerful enough then that can trip the protection on.
 
#3
Thanks!!

Any recommendations on lipo checker? I guess I'll have to buy that in order to check this out. Serious newbie here - have no other tools beyond the mini kit, the power pack, the battery, transmitter, and a charger.

Regarding balancing - that's how I charged it on my first troubleshoot. I connected the leads to the charger, connected the lead to the battery, then connected the balance lead to the charger. I think* that's the right way to ensure a balanced charge...?

Just to add one additional point, the battery pack is Tattu 3S LiPo Battery 75C. So definitely over 40c there. At the office today, but I'll check out the volts once I can acquire a lipo checker and then do the testing.
 

FDS

Well-known member
#4
You usually have to select balance charge as an option, most are not set to default. Any lipo checker that can do individual cell voltages is useful, ones that do cell resistance as well are even more handy. They are around $10, check your local hobby shop as well as online.
That pack should have no problem, its got ample power IF all the cells are fine. It’s possible to get a bad one out the box. I would contact FT store customer service about this problem too, before throwing any other parts at it, if that’s where you bought from. Get stuff swapped if in any doubt.
 
#7
Bought this guy as the charger. Didn't see an option for balancing - but may have gotten directions wrong.

Yes all bought from FT so I probably still do that. Just trying to make sure I didn't do some sort of rookie mistake first.
 
#9
If you do not yet have a lipo checker. You can use a regular volt meter. The cheap / free harbor freight works good because the leads had sharp points. You can usually connect to the pins on the bottom side of the balance plug. My 3s batteries have 4 wires The red wire and the black wire ( battery pack ground ) on the other side of the plug will read the full output of the pack. The red wire and the one next to it will read the voltage of 1 of the cells. The ground and the wire next to it will read the voltage of the second cell. The 2 middle wires will read the voltage of the 3th cell. The 3.x volts cells are just connect in series inside the battery pack. The cells will read over 4 volts fully charged. ( about 4.2)
I think my battery checked was about $10.00 or under. You need to check you batteries after your flights and you can set a timer on you transmitter or cell phone to know how long to fly. That way you will not run your batteries to low and they will last longer

Good luck and happy flying
 

FDS

Well-known member
#10
That charger should automatically balance charge, it’s super basic. I prefer ones with a proper Storage function. The Imax B6 clones are good for that, under $15 and better than the type you have although they need a 12-15v DC power supply for mains. A better charger will help you get the most out of your batteries.
I don’t think you have made any obvious mistakes, you methodically went through all the options and tested thoroughly.
 
#11
@FDS thanks! Yea I really didn't know what I was buying so just tried to make sure I got something that would work. I'll look into the Storage function ones as an upgrade. Appreciate it and thanks for encouragement!
 

FDS

Well-known member
#12
Something to think about when you have more than one battery! The cell checker will help a lot with managing the voltage. You want to stop flying with it about 3.6 v per cell (3s, 3x3.6=10.8v) and store it at about 60-70% charge, about 3.7-3.8v per cell. That will help keep your battery in good shape and give you consistent flight times.
 

basslord1124

Well-known member
#13
Yeah, I think my 1st lipo charger looked a lot like yours. Get you something with a digital display so you can have more flexibility and can see more info on your batteries. I hear lots of good out of the Imax B6's. This was my 2nd charger and it served me well for a while...

https://hobbyking.com/en_us/turnigy...V2EsNCh32Yw3SEAQYASABEgKeiPD_BwE&gclsrc=aw.ds

Growing, learning, and upgrading is all part of the hobby. And we all gotta start somewhere. ;)
 

Paracodespoder

Well-known member
#14
Just so we’re clear, you didn’t use screws that were to long and cut into the copper wires inside the motor right? (Don’t ask how I know that would cause that problem :rolleyes:). From your description I would say that one of the motor to esc wires has a bad connection, I had the same issue on my c-pack motor, did the exact same thing as the video you linked to. After fixing the wires it works as good as new.
 

Hoomi

Active member
#15
As for a checker, these are pretty common AND cheap. Shoot, get a couple of them if you want...

https://hobbyking.com/en_us/hobbyki...VjwOGCh0ZhAzzEAQYBCABEgJ-mvD_BwE&gclsrc=aw.ds
I bought a 5 pack of those off Amazon shortly after getting my first plane. Since I work in electronic calibration, I took them to work and checked the accuracy. While not quite accurate enough to use for calibrating anything, they are close enough for our purposes.

I tried using them for a low battery alarm on the airplane, but unfortunately, my hearing isn't good enough to hear the alarm beep when the plane passes by.
 

buzzbomb

I know nothing!
#16
my hearing isn't good enough to hear the alarm beep when the plane passes by.
Yep. Same problem here. Tried it, and after the planes go down, I walk out and pick them up and then I hear the alarm. I've been considering options to mount the alarm on the outside. Meanwhile, I got a trans with telemetry that'll tell me when the battery is low. Different options.
 
#18
@Paracodespoder It's not impossible. I got 3 sizes of screws for the motor from the power pack package. I used the middle length first and then read stuff about bad things with longer lengths so backed out and went with shortest one's they sent. What would my next steps in troubleshooting that be?
 

Wildthing

Well-known member
#19
I bought power pack A and the mini corsair build a few weeks back. Just finished the whole project. Immediately running into a similar problem that I saw someone else hit with Power Pack C on another thread. They posted this youtube video which shows my exact problem. The build is all straight "out of the box" stuff from Flite Test. I'm new to the hobby so I'm not customizing or anything yet.

I didn't see an exact resolution on that thread or things to really try. Just hoping to get some troubleshooting ideas.

So far, I've:
  1. Ensured battery is fully charged
  2. Re-calibrated the ESC with transmitter throttle range.
  3. Checked the motor connections to the ESC.
  4. Check connections to the transmitted for ESC
Other ideas?
If by chance and if you have an extra esc, motor and rx you could try each piece ONE at a time to find the culprit , process of elimination.