Community
Wiki Posts
Search

Amp draw

Thread Tools
 
Search this Thread
 
Old 06-29-2005 | 04:10 AM
  #1  
blatman's Avatar
Thread Starter
Tech Rookie
 
Joined: May 2005
Posts: 19
Default Amp draw

Hi guys, can someone tell me what the amp draw of a mod motor is.
blatman is offline  
Old 06-29-2005 | 05:44 AM
  #2  
Stonzy's Avatar
Tech Master
 
Joined: Mar 2003
Posts: 1,482
From: Australia, Tweed Heads
Default

Need more information
Eg, How many turn is the motor.
At how many Volts that you want to messure amp draw.

Each motor is always different as well.....

Could only give a rough guide only even with all the details.
Stonzy is offline  
Old 06-30-2005 | 03:03 AM
  #3  
Team Duratrax's Avatar
Tech Master
 
Joined: Aug 2004
Posts: 1,674
From: NSW, Albury/Wodonga
Default

Yeah theres other things to take into consideratin but roughly around 35-42amps.

Sean
Team Duratrax is offline  
Old 06-30-2005 | 03:34 AM
  #4  
Stonzy's Avatar
Tech Master
 
Joined: Mar 2003
Posts: 1,482
From: Australia, Tweed Heads
Default

35amps????? What motor pulls that many amps?
Stonzy is offline  
Old 06-30-2005 | 04:49 AM
  #5  
Tech Master
 
Joined: Jan 2003
Posts: 1,296
From: NSW Australia
Default

I thought it would of been a lot more?

Say you are getting 10mins from a 3300mah battery (and ur getting 3300 from the battery so maybe ur using a 3600 :P ). That means your pulling a average of 19.8 amps (3.3amps/hr = 19.8amps in 10mins). Now, thats if your on the throttle that whole ten mins, and ur not so lets say ur on it 75% of the time. thats now 29.7 amps.. ?

Drop the runtime down to 5mins and we have almost 60 amps at throttle usage of 75% of the time? That seems way too much - where have I gone wrong?.

(ok you also have servos, receiver but im talking roughly rough...)
au_Nightmare is offline  
Old 06-30-2005 | 05:13 AM
  #6  
Stonzy's Avatar
Tech Master
 
Joined: Mar 2003
Posts: 1,482
From: Australia, Tweed Heads
Default

I was going by a motor run in feature on the Pulsar competition charger. At 5 volts mod motors normally pull around 10-14 amps from my experience.

Depending on the motor and timing etc etc..
Stonzy is offline  
Old 06-30-2005 | 05:39 AM
  #7  
Rossco's Avatar
Tech Addict
 
Joined: Dec 2004
Posts: 635
From: GO WODONGA
Default

so if ur drawing say 60 amps why are speed controllers rated to over 300 amps and still only handle a 8turn?
Rossco is offline  
Old 06-30-2005 | 05:42 AM
  #8  
Stonzy's Avatar
Tech Master
 
Joined: Mar 2003
Posts: 1,482
From: Australia, Tweed Heads
Default

When a motor is actually in a car then the amp draw will be a lot higher than what i mentioned above because of the extra load that the motor has. EG: Weight of the car, Gears, friction, tractionof the track etc etc

Amp draw on a motor which isn't in a car is around 10-15amps or there abouts....
Stonzy is offline  
Old 06-30-2005 | 07:05 AM
  #9  
Team Duratrax's Avatar
Tech Master
 
Joined: Aug 2004
Posts: 1,674
From: NSW, Albury/Wodonga
Default

Stockers pull around 20-25amps in a TC am i right?

Sean
Team Duratrax is offline  
Old 06-30-2005 | 12:23 PM
  #10  
Tech Master
 
Joined: Jan 2003
Posts: 1,296
From: NSW Australia
Default

Because 60amps is average of "on throttle time" - you have huge amps from stand still / low rpm and they decrease as RPM increase (more RPM = more generated power limiting current flow.. - the motor becomes a generator, the generated voltage limits flow of current coming in because its got its own current trying to get out).

Stall a motor out and see how many amps you get - its like a short.

Originally Posted by Rossco
so if ur drawing say 60 amps why are speed controllers rated to over 300 amps and still only handle a 8turn?
au_Nightmare is offline  
Old 06-30-2005 | 03:58 PM
  #11  
OZDC's Avatar
Tech Fanatic
iTrader: (16)
 
Joined: Mar 2002
Posts: 931
From: Melbourne
Default

The initial current on an electric motor is very high, a 60amp + peak for a few ms would not be out of the question. Thats why the speedies are rated so high, to be able to handle the initial current at startup.

DC
OZDC is offline  
Old 06-30-2005 | 05:29 PM
  #12  
Team Duratrax's Avatar
Tech Master
 
Joined: Aug 2004
Posts: 1,674
From: NSW, Albury/Wodonga
Default

And also when you hit something to a stand still you can send 90 amp spikes through the esc, so that another reason why escs have to handle 3 times the amperage from a motor.

Sean
Team Duratrax is offline  
Old 06-30-2005 | 07:16 PM
  #13  
OldSkool's Avatar
Tech Fanatic
iTrader: (10)
 
Joined: Jul 2003
Posts: 799
From: Barnawartha, Victoria
Default

A motor under a set load ie: Fan, will give a constant amp draw but off road cars even 540,s can draw over 100 amps, it's all load . Bumps and jumps

This is why speedys have peak amp draw @ around 360 amps.

Think about it how much current is drawn when you nail a wall with your car.

If you have a charger like the LRP and you run the motor run in feature have it set at say 3-5volts, then grab the spinning arm and you will see the amp draw jump.
And most likely the unit will shut down.

The old Tekin discharger had a race simulator discharge which would have the amp draw "spike' to get the batterys used to racing conditions.
OldSkool is offline  

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are Off



Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service -

Copyright © 2026 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.