K01S

I've got the Great Planes Super Sportster EP and I'm getting it ready for it's maiden flight. On Sunday night/Monday I trickle charged the battery for 21 hours (battery is 2100 mah and trickle charge is at 100 mah per hour). On Monday night I followed the motor break-in by running it (Speed 550) without a prop for 15 minutes (actually it was 3 runs of 5 minutes each with a cool down period after each 5 minute run). It all went well. I put the battery back on the charger to fully discharge it and then set it up for another trickle charge until last night.

Last night the plan was to run the motor again with a propellor until the battery ran out and the motor shut off. I re-installed the prop and battery but I could not get the motor to run. I rechecked all connections and it all looked good. I disconnected the battery and measured the voltage and it read 10 VDC. The battery pack is a 7 cell NiCad. It says 8.4 VDC and 2100 mah on the battery pack. The battery should have been 8.4 (1.2 V times 7 cells) but I measured 10 V???

I'm new to electric flight and I'm not really sure what to do next? Does anyone have any suggestions? Is there some sort troubleshooting checklist to follow to figure out what's wrong?

Any suggestions would be very much apprecaited.

Best Regards, -ko1s []

normgoyer

The extra voltale is called a surface charge and is in the correct range for that pack. I would check out the ESC to make sure that it is working properly. A NiCD pack is very reliable, look elsewhere Norm

K01S

OK Norm, thanks for the help! - -ko1s [8D]

K01S

I'm at work right now so i can't do anything yet but I'm thinking about the next step to try. If I disconnect the motor from the ESC what should i see (electrically) at the black and red ESC leads? Should the voltage go up and down when i move the throttle stick on the xmtr.?

Any suggestions on a test to narrow the problem down? I agree with your thought that it might be the ESC but I'm not sure how to test it.

Regards, - ko1s []

normgoyer

Hi, how are things out in Bourne? We are originally from Northampton, MA and vacationed at North Truro for over 20 years with our six kids until moving west in 1970. The only way that I found works every time is substition. Borrow an ESC the same range or larger than yours and see if it works then. I have blown 3 ESCs through carelessness. Bateries you can check with a volt meter. You can also put 6 volts direct to the two leads of your motor (must be brush variety to do this) If you have volts from battery and motor turns when you put 6 volts direct to leads the trouble is the ESC. Norm

K01S

Thanks a lot for the info Norm, I'll give it a try. Not sure where I can get a 6V source though. Things are great here on the Cape. This is the tourist season so there are lots of folks visiting the area. My favorite season starts in September when the tourists leave and kida are back in school. Us older folks call it the second season and it by far the best time.

Anyway, thanks agian for the info Norm! - k01s [8D]

normgoyer

You can use 12 vols from a car battery for only a split second. If the motor runs it is not the motor. the only other problem could be the switch and you can check that with a ohm meter.

Our daughter still lives in Hadley, MA and she and her husband go to the Cape every other weekend during the summer and then once a month during the off season which they like better. Her daughter and our grandaughter was born in Hiannis.

I use to fly out to Provincetown airport with one my planes. I have landed there many times in singles and twins with a load of kids and camping gear. Norm