Buck Barker

My Feedback: (4)

Hi: I just finished a Top Flite P-47, Which I powered with electric, . I hooked it up to a watt meter. It started right up, but just after the throttle stick was pushed by about 60%, it cuts out. At that pointy the watt meter was showing about 1400 watts, and 23 amps...The motor is an Atlas 5030. ESC, a Castle 85HV. Runnig with two flight power, 25C, 5 cell, 3700mah, delivering37V t the motor.What is going on here?

Dr Kiwi

Do you mean 43A??? If your pack is doing okay, then 1400W on 10S (maybe 35v under load) indicates ~40A.

If you are reading 1400W/47A.. that's only 3v/cell... so you are hitting LVC.

Buck Barker

My Feedback: (4)

Thank you ever so much. My only problem is what is LVC? Can the throttle be adjusted so full throttle is full stick movemnt? If LVC happens to be all I can get.

Dr Kiwi

LVC: low voltage cut-off is typically set on the ESC to kick in at around 3.3v-3.5v/cell, so that one's batteries are not ruined by over-discharge.

In your case, the symptom of cutting out at less than full throttle suggests that the packs can't supply the required current and their voltage under load is dropping below LVC cut-off... but until we have some accurate figures we don't know what is happening... you said 1400W @ 23A... but that would require >60v so that cannot be correct.

Buck Barker

My Feedback: (4)

I thank you again. From what I can see I beleive yuo are correct. I will run the motor again this weekend, and try to get a better picture of what`s going on. All I have is a watt meter to work with, but maybe I can be more precise. It`s kind of a scary thing when it gets up to the 1400 watts. I was running a 20x10 prop, and it really pulls. Like it wants to get away . The Buckster

Buck Barker

My Feedback: (4)

Hi Dr. It`s me again. I ran my P-47 again this morning and the cut out happened at 1445watts, at 47amps, and the voltage was around31V, but after pushing the throttle up to varify my readings several times, it suddenly went to full throttle with out cutting out. At full throttle the watt meter showed 2200W, at 76amps, and about 28V. I tried it several times and it worked each time. Now I am really confused. How can I trust it?
the Buckster

Dr Kiwi

What do you have LVC set at.... your 1445W/47A/31V should have tripped LVC if that is set at the typical 3.3v-3.5v/cell... but why it allowed 2200W from 76A at only 2.8v/cell I cannot understand.... that will kill your batteries.

Buck Barker

My Feedback: (4)

I don`t know any more. I have tried smaller props, smaller batteries etc, etc. Maybe if I had some help from Castle, we could figure out what is going on. I tried talking on the phone to them, but my hearing is so messed up I couldn`t understand the man behind the phone. I tried Email, but only heard from them once. I have put it all back together, and put it away.I have never had any trouble with the smaller motors, but I am totally lost on this one. I do thank you for trying to help,