Large Model Association Forum

Can anyone help with the diagnosis of a small electric flight problem. With a brand new fully charged battery the prop spins at a slower speed than required for flight and then packs up altogether after a few moments. It will restart, then does the same thing. How can one test the speed controller or motor itself to establish the cause and cure? Any advice would be welcome as I`ve been `nitro`up to this time.
Gerard Jordan at gerard.2@virgin.net

Sound like an ESC being overloaded... But there are so many things with electric. Start with the basics..

Do you have a watt meter? Have you measured the current and wattage during the start up as that will give you a clue if it's drawing too much for the ESC.

Hi Gerard, Does your ESC have a Switch or a jumper on it if so change the switch or remove the jumper, it sounds like you ESC is set to the wrong volts for your battery , i.e. 7.2v instead of 11.1v.

Hope you get it sorted.

Got to agree with Stuart, Put a a meter on it to measure the current draw and voltage first off. With out this its all guess work. A decent Watt meter is a must in Electric flight. Without it you have no idea of what is going on . Just one size of prop to big is enough to destroy a motor / esc .

Simon

Suart, Dave, Simon,
Many thanks gentlemen for your collective response. The aeroplane is a CenturyUK Cessna 182, which, when I bought it, some time ago used a smaller battery with 7 cells. This model is now quoted as using a 9.6 volt 8 cell battery. The [u]liklihood is that the speed controller is the problem, being the original one, but the symptoms are exactly the same as when I first tried it with the original battery, fully charged, which would seem to make that equally unlikley as well I dont have a wattmeter at the moment but the need for one is now evident. When the problem is solved I`ll put it online for the benefit of anyone buying a new battery for this model.
Gerard Jordan 4001