PDA

View Full Version : 400-lipo


Plane_freak
08-30-2005, 06:03 PM
I bought a Funny Park some time ago. It came stock with a 400 3:1 motor. Plenty of power with the prop. I have been using a Kokam 2 cell 1500mah. After a 15 minute flight at half throttle it is luke warm. will this damage the battery? What is a safe tempreture that this will handle?
Could I use a 3 cell 1300mah? will it heat up?

Red Scholefield
08-30-2005, 07:56 PM
What you are seeing is quite normal. A 3 cell pack will deliver more power so it will get warmer still if run full throttle.

2dogrc
08-30-2005, 08:20 PM
I bought a Funny Park some time ago. It came stock with a 400 3:1 motor. Plaenty of power with the prop. I have been using a Kokam 2 cell 1500mah. After a 15 minute flight at half throttle it is luke warm. will this damage the battery? What is a safe tempreture that this will handle?
Could I use a 3 cell 1300mah? will it heat up?

Well..the 3 cell battery will provide more power, 11.1 Volts. That is a lot for a 400 size motor! It will run, but the motor will not last as long! I have used 3 cells on GWS 350's and it burns them out pretty quick! If you want to try it, limit your flights to a couple of minutes.

Remember volts= power, and amps=duration.

Good luck!

Matt Kirsch
09-02-2005, 04:45 PM
Luke warm will not damage the battery, but full throttle on that setup is pushing the battery to its limits. Kokam 1500 packs are 8C rated, meaning they can handle (1500 * 8 / 1000), or 12 Amps. A properly-configured 400 motor setup will draw about 12 Amps on a 2S LiPoly, so you're in the ballpark.

However, if you go to a 3S pack, and increase your voltage by 50%, you will also increase your current by 50%. That's Ohm's Law at work. 18 Amps will burn out the motor and battery pack in no time flat... The way to fix that is with a smaller prop, but you still have a problem with a bushing motor spinning way faster than it was ever designed to go, and it will still burn out very quickly compared to "normal" usage.

Plane_freak
09-02-2005, 07:23 PM
I have tried other props. 1047, 9070 (recommened), 1060, finally 1080hd. I stuck with this because with any other prop the battery would heat up but I still had no power. I am going to buy a 1070 if they make one. That should be a good mix for draw and power.:D

Matt Kirsch
09-04-2005, 01:49 AM
Excellent! That's exactly what you need to do sometimes: Experiment with different props to see which one fits your style best.