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Old 06-11-2014, 06:47 AM   #1
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Default Estimated Run Time

Hi,
Just need to clarify some figures as I'm new to this R/C car scene. I am getting a 4400 mAh battery and pairing it with a 7.5 T motor from Speed Passion, bundled with an ESC that draws 40 A on normal load. Based on my calculations, the battery will last 6 minutes before running flat, is it true? Thanks!

Battery: http://www.hobbyking.com/hobbyking/s...case_Pack.html

Motor & ESC: http://www.rcmart.com/speed-passion-...o-p-27270.html
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Old 06-11-2014, 08:14 AM   #2
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The esc does not draw the amps, the motor does. The esc just controls the flow of power from battery to motor. You should get a more than 6 min just based on experiance. Off road guys run 4600 shorties with 6.5/7.5 motors and make 10 minute mains. Run time is going to depend on gearing, time spent at full throttle and braking. Excessive wheel spin will also cause a decrease in runtime, as does a heavy car and a bound up drivetrain.

But may I ask if your that new to the RC scene that you are unsure of run time, why would you get one of the fasfest motors you can buy right from the start?
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Old 06-11-2014, 08:20 AM   #3
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The esc does not draw the amps, the motor does. The esc just controls the flow of power from battery to motor. You should get a more than 6 min just based on experiance. Off road guys run 4600 shorties with 6.5/7.5 motors and make 10 minute mains. Run time is going to depend on gearing, time spent at full throttle and braking. Excessive wheel spin will also cause a decrease in runtime, as does a heavy car and a bound up drivetrain.

But may I ask if your that new to the RC scene that you are unsure of run time, why would you get one of the fasfest motors you can buy right from the start?
The motor was actually bundled with a second hand TA-05 chassis I got through a friend for quite a cheap price, round abouts USD 100. I'm doing mostly R/C drifting which will not require me to go full throttle all the way so will I get more battery time out of it?
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Old 06-11-2014, 08:25 AM   #4
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Yes you should if not going full throttle, but drifting is going to drain the battery pretty good due the the nature of intentionally spinning the wheels. Also with drifting you going to build up alot of excess heat, I would suggest a cooling fan if you dont have one. You might want to look up the drifting thread on here as those guys might be more knowledgeable.
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Old 06-11-2014, 08:52 AM   #5
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Yes you should if not going full throttle, but drifting is going to drain the battery pretty good due the the nature of intentionally spinning the wheels. Also with drifting you going to build up alot of excess heat, I would suggest a cooling fan if you dont have one. You might want to look up the drifting thread on here as those guys might be more knowledgeable.
Ah I'll have a look over there, thanks!
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Old 06-11-2014, 09:12 AM   #6
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Try this.

http://dhrc.rchomepage.com/RolloutCalc.htm#eff
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Old 06-11-2014, 04:26 PM   #7
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That ESC states that it can handle motors > 7.5 turns (like 8.5 - 25.5 turns). Thus, you shouldn't use it with a 7.5 turn motor.
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Old 06-13-2014, 05:57 AM   #8
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Ah, just what I need, thanks!

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That ESC states that it can handle motors > 7.5 turns (like 8.5 - 25.5 turns). Thus, you shouldn't use it with a 7.5 turn motor.
I'm not sure if my motor is a 7.5 T or not, will need to check with my friend as he has the full specs. Thanks!
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