Model Boat Mayhem

Mess Deck: General Section => Chit-Chat => Topic started by: Boatbuilder2011 on June 09, 2011, 08:15:42 pm

Title: Runtime with lipo battery and brushless motor
Post by: Boatbuilder2011 on June 09, 2011, 08:15:42 pm

Hi trying to work out what run time I will get out of a 1300 lipo running a 1400kw brushless motor?

Title: Re: Runtime with lipo battery and brushless motor
Post by: andyn on June 09, 2011, 09:08:23 pm

Impossible. What's the average current draw of the motor?

Title: Re: Runtime with lipo battery and brushless motor
Post by: malcolmfrary on June 09, 2011, 10:07:16 pm

Quote from: Boatbuilder2011 on June 09, 2011, 08:15:42 pm

Hi trying to work out what run time I will get out of a 1300 lipo running a 1400kw brushless motor?

Quote

Impossible. What's the average current draw of the motor?

.....and it's probably KV for 1000 rpm per volt, rather than kilowatts.  Even knowing the current draw according to the instruction book probably doesn't help a lot. since the main thing loading the motor is going to be the prop.

Title: Re: Runtime with lipo battery and brushless motor
Post by: Boatbuilder2011 on June 09, 2011, 10:36:02 pm

Ok guys no worries thanks anyway

Title: Re: Runtime with lipo battery and brushless motor
Post by: nick_75au on June 13, 2011, 10:07:13 am

And now for a sensible answer ;D

I have a 1250 Kv 36 mm motor driving a 40 mm 2 blade Raboesh prop, on 3 cell it draws 40 amps at full throttle, I get about 20 30 minutes runtime using a 5000 mAH battery providing I am conservative on the throttle, same  setup your going to get about 1/4 of that time on the 1300 mAH battery.

If its a smaller prop that runtime will be increased,

What sort of boat is it?

cheers nick