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Emax Babyhawk problem

BoFPV

New member
#1
I received my Emax Babyhawk 3 days ago and it flew great untill today, it suddenly lost about half of its power. When I "puch" the throttle it barely ascends.

I used a 25c 370mAh 2s battery.

Here's some DVR, stick cam footage of the problem.

If you have a suggestion on what the problem may be, please let me know.
 

PsyBorg

Wake up! Time to fly!
Mentor
#2
You could have popped a cell running it hard. I did that one one of my Graphene 4s 80 c batteries in my Alein. It would cruise great but any time you needed punch forget it. Watch this video and you can actually see when it popped. No swelling or heat the one cell just wouldn't hold the power for high amperage use.

 

Hai-Lee

Old and Bold RC PILOT
Mentor
#4
PsyBorg is correct in the majority of cases showing similar symptoms and sadly the cause is heat and discharge related. It appears that one cell has gone High resistance. As a recommendation I suggest that you buy and use a battery monitor/alarm to ensure that you do not discharge batteries too far.

Additional causes can be rather weird.

Where a flight controller is used the throttle channel can be "recalibrated" in flight due to a glitch. This is apparent when fitting a fresh, fully charged battery, to the craft and it still behaves the same.

A low resistance or leakage between motor windings can really chew up the motor current and than the remaining current for flight is lower.

Finally a dodgy ESC and the flight controller is trying to balance the attitude of the craft by reducing all other throttle settings.

So in summary. If fitting a new battery removes the problem it was battery related and if a new battery does not fix it you will have a "Sherlock Holmes" ahead of you!

Have fun!
 

BoFPV

New member
#5
You could have popped a cell running it hard. I did that one one of my Graphene 4s 80 c batteries in my Alein. It would cruise great but any time you needed punch forget it. Watch this video and you can actually see when it popped. No swelling or heat the one cell just wouldn't hold the power for high amperage use.

Thanks for your suggestion, I think you're right.

I contacted hobbyking about this problem. They think the problem is in the babyhawk itself so they refunded me the entire thing and I don't even have to send it back!

I'll probably use the refunded money to buy batteries with a higher C-rating I'll probably buy some of these: https://hobbyking.com/en_us/turnigy-nano-tech-300mah-2s-35-70c-lipo-pack.html

If this doesn't solve the problem I'll look for new esc's and motors, maybe the gremlin powerpack...
 

BoFPV

New member
#6
I didn't connect a battery alarm because of the weight but I did set a 3 minute timer to ensure that I don't drain the battery completely. I checked each battery after a flight and they where never below 7v.
 

BoFPV

New member
#7
Thanks for your suggestions, I just ordered some batteries with a higher c-rating NEW= 35c continues 70burst OLD= 25c continues 40 burst
 
#8
Thanks for your suggestions, I just ordered some batteries with a higher c-rating NEW= 35c continues 70burst OLD= 25c continues 40 burst
Was it the batteries? I am having a similar issue but have tried multiple batteries on the quad and all act the same. I also have some weird issues where the 2nd motor seems to speed up faster than all of the other motors...Anyone have any ideas? Is it just a bad esc? Or is the flight controller more the issue at that point not speeding up the other motors but instead slowing all others down? Any help would be appreciated!
 
#9
Same problem, Babyhawk lost its power

I received my Emax Babyhawk 3 days ago and it flew great untill today, it suddenly lost about half of its power. When I "puch" the throttle it barely ascends.

I used a 25c 370mAh 2s battery.

Here's some DVR, stick cam footage of the problem.

If you have a suggestion on what the problem may be, please let me know.
I am having the same problem. I run 450 70c 2s and have 6 of them, all check out fine. Something is going on with the FC or ESC's, becuase I run full throttle now and can bearly keep it off the ground.
 

PsyBorg

Wake up! Time to fly!
Mentor
#10
What size wire and what connectors are used on these? The Gremlins use the same stock power pack and they rip on 2s 45c 450 mah lipos with XT 30 connectors. Mine is heavy at 147g all up weight.

If the wire is too small and they use simple jst connectors they wont transfer the power properly. This shows it on 2s and 3s


This is a ~2/3 throttle cruise on the 3s setup.