Using 2S Lipos on brushed motors? OK?? - WattFlyer RC Electric Flight Forums - Discuss radio control eflight

Power Systems Talk about motors, ESC speed controllers, gear drives, propellers, power system simulators and all power system related topics

Using 2S Lipos on brushed motors? OK??

Old 01-04-2009, 08:06 AM
  #1  
diverdon
Member
Thread Starter
 
diverdon's Avatar
 
Join Date: May 2007
Location: Jupiter , Fl.
Posts: 742
Default Using 2S Lipos on brushed motors? OK??

Hello , I am putting together a plane for a friend of mine who has helped me so many times with lots of different things . I am going to use a brushed motor and the voltage listed is 9.6 volts .. Can I use a 2 cell lipo motor with this motor ?? Seems like a good Idea to me ..

What I am building is a super cub as a lot of you know you can buy the parts pretty cheap without the "crash saving" stuff I have this 480 motor eflite that fits the transmission real good .. it might not e right but I'm gonna use the transmitter that comes with the plane . Good enough for a beginner ? I think ..

But anyhow the only question is the battery 2 cell lipo .. should work fine eh . ... Thanks .. Hope everyone had a safe holiday , Don J.
diverdon is offline  
Old 01-04-2009, 10:19 AM
  #2  
slipstick
Super Contributor
 
Join Date: Oct 2005
Location: N.Staffs, UK
Posts: 2,350
Default

Yes you can use a 2S (7.4V) battery with a 9.6V motor...but the power you get out of it will be seriously reduced. You might want to try a bigger prop than usual to get some of the power back but then you need to be careful that the current doesn't get too high.

9.6V nominal brushed motors were typically used on 12V or more in the real world. I think I'd be looking at a 3S battery for it .

Steve
slipstick is offline  
Old 01-04-2009, 10:41 AM
  #3  
Murocflyer
WAA-08 Pilot #1
 
Murocflyer's Avatar
 
Join Date: Mar 2007
Location: Edwards AFB, CA
Posts: 7,044
Default

Don,

That's very generous of you. Good job. As mentioned by Steve, just be careful of the amps you are drawing out of those batteries with the 480 motor. Sounds like you are gearing it, so that will help. The 7.4V will make your plane pretty anemic though. A 3 cell is definitely the way to go.

Frank
Murocflyer is offline  
Old 01-04-2009, 12:04 PM
  #4  
diverdon
Member
Thread Starter
 
diverdon's Avatar
 
Join Date: May 2007
Location: Jupiter , Fl.
Posts: 742
Default

Thanks everyone , I'm OK going with the 3 cell lipo jus was afraid that it might burn out the motor .. My first cub I even did the "Break in procedure . i forget the whole thing but it involved using water to run the motor in .. Anyhow I started it up and the motor cooked in 10 secomds ,

Just my luck I guess .. No Big Deal Gonna try it again.No Water break in thou Thanks , I'll Let you all know how it works out , Don J.
diverdon is offline  
Old 01-04-2009, 12:21 PM
  #5  
Murocflyer
WAA-08 Pilot #1
 
Murocflyer's Avatar
 
Join Date: Mar 2007
Location: Edwards AFB, CA
Posts: 7,044
Default

Good luck Don and let us know how it turns out.

Frank
Murocflyer is offline  
Old 01-04-2009, 01:20 PM
  #6  
gfdengine204
Super Contributor
 
gfdengine204's Avatar
 
Join Date: May 2007
Location: Sandwich, IL
Posts: 9,565
Default

Don,

2 things:

1. The 3S lipo may be a little more than that motor is designed for, so the brushes may wear out prematurely. Just so you are forewarned. Of course, if it DOES fail prematurely, it's a good excuse to replace it with a brushless setup.

2. Your ESC for that brushed motor may not be Lipo-friendly, meaning it's Low Voltage Cutoff will not be appropriate for Lipo packs. If you are not using an ESC specifically compatible with Lipos, you should run a short flight, land, and check battery voltage. You do not want to run that pack lower than 3.0V/cell (and preferably, IMHO 3.3V per cell to be on the safe side). For 3S that would be no lower than 9.0V (9.9V with 3.3V rule). Run a short flight of, say, 5 minutes, land, measure voltage and that should give you an idea where you are. Recharge your Lipo, note how many mAh go back in, and that should confirm your findings. You don't want to run these down too low or you risk ruining the pack.
gfdengine204 is offline  
Old 01-04-2009, 03:16 PM
  #7  
skyvolt12
Member
 
skyvolt12's Avatar
 
Join Date: Aug 2005
Location: Bowie, Maryland
Posts: 183
Default

Hi everyone,
I have a similar problem except a much better motor (Astro 05) direct drive. The plane I have it in is Bob Kopski's "Skyvolt", a great flyer. I had thought of 2 cell Lipo's, but now I am considering three cells and propping it to keeping it at 30 amps. I have had a FMA Lipo charger for a couple of years now but have yet to venture in to Lipo's. Fear of explosive out comes I guess. I sure would welcome any comments. Thanks in advance
Kenny
skyvolt12 is offline  
Old 01-04-2009, 03:36 PM
  #8  
Murocflyer
WAA-08 Pilot #1
 
Murocflyer's Avatar
 
Join Date: Mar 2007
Location: Edwards AFB, CA
Posts: 7,044
Default

Kenny,

Not a problem at all. This says it can run on 3-5 LiPo cells.

http://www.astroflight.com/index.php...products_id=72

Frank
Murocflyer is offline  
Old 01-04-2009, 03:57 PM
  #9  
Crash Test Dummy
Super Contributor
 
Crash Test Dummy's Avatar
 
Join Date: Aug 2005
Location: Sugar Grove
Posts: 2,748
Default

Re: Lipo cut off. If you stay with a brushed set up you can get some nice brushed controlers from Electrafly that will detect 2,3,and 4S Lipo cut offs. This will allow you to get max flight time without the worry of killing you Lipos.

http://www.electrifly.com/escs/gpmm2005.html

CTD
Crash Test Dummy is offline  
Old 01-04-2009, 04:17 PM
  #10  
skyvolt12
Member
 
skyvolt12's Avatar
 
Join Date: Aug 2005
Location: Bowie, Maryland
Posts: 183
Default

Hi again--- Super fast reply. The Astro ad that you are showing is for brushless 05.
skyvolt12 is offline  
Old 01-04-2009, 05:15 PM
  #11  
Murocflyer
WAA-08 Pilot #1
 
Murocflyer's Avatar
 
Join Date: Mar 2007
Location: Edwards AFB, CA
Posts: 7,044
Default

Originally Posted by skyvolt12 View Post
Hi again--- Super fast reply. The Astro ad that you are showing is for brushless 05.
Oh OK. I don't see them listed on their site and since I don't have one I can say for sure. Odds are it will be just fine but give them a call tomorrow to be sure.

I did find this for you though.
http://www.rcgroups.com/forums/showt...05#post3857710

Frank
Murocflyer is offline  
Old 01-05-2009, 04:12 AM
  #12  
diverdon
Member
Thread Starter
 
diverdon's Avatar
 
Join Date: May 2007
Location: Jupiter , Fl.
Posts: 742
Default

Hello , Thank you everybody for all of the great advice . I will let you know how it comes out .. Oddly I have 3 or 4 "Projects" going on right now ? That doesn't seem to happen to anyone else does it ??

Thanks Again , Don J.
diverdon is offline  
Old 01-05-2009, 04:43 AM
  #13  
Crash Test Dummy
Super Contributor
 
Crash Test Dummy's Avatar
 
Join Date: Aug 2005
Location: Sugar Grove
Posts: 2,748
Default

3 or 4 projects at one time Naw, that never happens to me, LOL!!! Are you kidding, if I'm not building something, I'm fixing the last couple of planes I just crashed, LOL!!

CTD
Crash Test Dummy is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
wollins
Batteries and Chargers Forsale/WTB
5
10-04-2008 08:32 PM
jtcarn
Motors and Speed Controllers for sale & WTB
0
09-09-2008 01:56 AM
tmackel
Batteries & Chargers
3
09-10-2007 12:07 AM
Warden
Batteries & Chargers
2
11-28-2005 02:57 PM
Milton
Motors and Speed Controllers for sale & WTB
2
11-11-2005 02:35 AM

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 On


Quick Reply: Using 2S Lipos on brushed motors? OK??


Contact Us Archive Advertising Cookie Policy Privacy Statement Terms of Service

Copyright 2018 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.

Page generated in 0.07481 seconds with 13 queries