Raptor Freewing dies after 2 minutes

[F22]

I have a F22 raptor my club member gave it to me . with new looking 4S lipos .

I just charged it up and tried it on the house floor I turned it around and ran it 3/4 throttle for about 2 minutes and it just slows down and dies . the batteries checked out with 3.9 volts . I know there are 3 version motors with this jet 3500KV ,3800KV, and 4300KV one recommends only a 3S lipo 1800mah the other 2 recommend a 4S battery 2200mah could this motor or esc have trouble say if this motor in this jet has a 3S recommendation and was ran with a 4S . maybe you can help me.

[ryramZ]

3.9 volts is not full charge. Look for 4.1 4.2 on cells. Also, if you ran it in the floor in the house it never got to unload which is hard on the power system to a degree.

[RRHandy]

I think what he is stating is that the battery still had 3.9 volts. My .02 ;)

[Grossman56]

Sounds like a dead cell, check every individual cell to see where the charge is. I had one like that at Nefi, three out of four cells were good, one bad resulted in an emergency landing with my P-51B after about two minutes of flight, no damage thankfully!
Got her on the ground and revved up to motor. she went to high RPM and then died off.

Grossman56

[F22]

I think what he is stating is that the battery still had 3.9 volts. My .02 ;)

Yes thanks

[F22]

Being that I have flown prop planes and went through all the electric stages of batteries , Nicads, Nimh and now lipo's .

my question is would I get longer run times with my F22 freewing jet by choosing a 3S 2200mah instead of a 4S 2200mah battery?

[themudduck]

Being that I have flown prop planes and went through all the electric stages of batteries , Nicads, Nimh and now lipo's .

my question is would I get longer run times with my F22 freewing jet by choosing a 3S 2200mah instead of a 4S 2200mah battery?

Well sure, you would get a longer battery run, but your motor would be running at a slower RPM and might not have enough power to fly the plane.

Regarding your problem, see if you can find a different fully charged 4S battery that you know is good, perhaps from a friend, and see if it does the same thing as a test. It doesn't have to be the exact same mah rating. If it does the same thing, then you can assume that the battery is not the source of the problem. Maybe the ESC has a problem. If the test battery runs fine for a longer time than your original battery, then that means that there's a problem with your original battery.

And I agree with Grossman, its quite possible you may have one bad cell. A "bad cell" will sometimes charge up to 4.2 normally, with your pack balanced, and then when you go to use it one cell will drop off much faster than the other cells. If you test your battery at that point, using the balance plug with a battery checker that shows the voltage of each cell, it will be really obvious if one cell is bad. I've had that happen a few times. Here's a pic as an example (this model is available from a larger number of retailers under different brands). These things are really useful and you should check your batteries after each flight.

[F22]

WAS BAD BATTERY WITH NO SWELLING AND A GOOD CHARGE . YET NO POWER

[themudduck]

Why are you using a bad battery?

[F22]

Why are you using a bad battery?

I dont use that battery any more , so I purchased a new one without any problems , its just that I have never had a battery go bad when , [when] it shows no sign of being bad . its the first . I guess Im still learning after 16 years of flying this is a new one. so someone in my club says it does happen however its rare that it the battery wasnt puffed and did hold a charge all even acrossed all 4 cells go figure. thanks any way .

[Marco Polo]

You may want to check the internal resistance (IR) of your batteries. A higher than normal IR will signal a battery that is getting weaker, possibly dying. Also note that cell IR is pretty much inversely proportional to cell capacity. Healthy 2200 mAh cell should have IR around 3-8mOhm depends on their C-rating. A 5000mAh cell should have about 1-3mOhm. If the IR is dramatically different between cells that could signal a problem as well. Remember also not to fly your batteries to low voltage cutoff (LVC), that is very hard on LiPos.

[RRHandy]

As a habit I check the battery after charge with the battery checker just to see if it is truly full charged, just for GP. R.

[F22]

As a habit I check the battery after charge with the battery checker just to see if it is truly full charged, just for GP. R.

Thank you I now do that I purchased a new 4S battery and it fly's great .

[F22]

Sounds like a dead cell, check every individual cell to see where the charge is. I had one like that at Nefi, three out of four cells were good, one bad resulted in an emergency landing with my P-51B after about two minutes of flight, no damage thankfully!
Got her on the ground and revved up to motor. she went to high RPM and then died off.

Grossman56

yes it was a bad batch of batteries ,I never saw this before in all the batteries I have purchased these 3 batteries were all bad .

[Grossman56]

Sucks don't it. Lost 2x 4000's last year!:Cold:

[F22]

Sounds like a dead cell, check every individual cell to see where the charge is. I had one like that at Nefi, three out of four cells were good, one bad resulted in an emergency landing with my P-51B after about two minutes of flight, no damage thankfully!
Got her on the ground and revved up to motor. she went to high RPM and then died off.

Grossman56

Thanks for your input , at least with a war bird you got some glide left to land with the jets Im finding they like power even on landings.