ESC control problem?
 

I have a FMS Donier Alpha Jet running a 70mm Electric ducted fan, with a 50A ESC on 4s 14.8v 2200kva 20c & 30c Lipo batteries. According to my calculations, based on the consistent voltage drop on 5 min runs, I should be able to run each battery up to 8 minutes safely before recharging. However the 1st time that I tried to run the 30c battery to 7 mins the Motor just stopped running at the 6 minute mark and the airplane crashed. On recovery of the aircraft, i noticed that the battery was hot. So i concluded that the battery must have over discharged and been destroyed. But I tested the batteryimmediatelyafterward and realized that the battery had above adequate charge to still run the airplane. So i subsequently flew the airplane with the stock 20c battery and it did the same thing after about 5 mins 30 secs...both batteries have been recharged and are still good.. I ensured that I did not run the motor on full throttle for more than 8secs..Could this be a problem with my ESC? .....Would switching my ESC to a 60A model fix this problem? And would there be any adverse effects of doing so?

RE: ESC control problem?
 

What was your LVC set at? It sounds as if you were hitting LVC in flight. The batteries might well have apparently adequate voltage under no-load conditions after the flight... but what about under load?

If the battery was hot after the failure......what was the current draw during the flight..... presumably too much.... which would explain why the voltage became too low... the one thing C-rating marketing hype never admits to is, "what is the under load voltage at the 20C-30C current draw"... answer... probably below the LVC setting!.

RE: ESC control problem?
 

To tell you the truth, I have no clue what the LVC is set to. I honestly never herd of that term before you mentioned it. As u may suspect, I am new to electric flight. How would I find this information? The manual was not very detailed and I don't recall seeing anything regarding this. Also is there any way to adjust this? What are my options?
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