Notices
Electric General Discussion General Discussion forum about rc electric related aircraft, accessories, flight, tips, etc.

which is more important

Old 03-06-2008, 11:48 PM
  #1  
sharpshooter223
Senior Member
Thread Starter
 
Join Date: Jul 2005
Location: richland, WA
Posts: 454
Likes: 0
Received 0 Likes on 0 Posts
Default which is more important

well after deciding to upgrade my planes i have also decides not to spend all of my money on my planes (i dont have a whole lot of money to begin with, im 16, i dont have a job). so i have decided i can either upgrade to lithium batteries or i can upgrade to brushless motors. which is the better thing to upgrade to?
Old 03-07-2008, 09:28 AM
  #2  
Walt Thyng
My Feedback: (9)
 
Join Date: Jul 2002
Location: St. Charles, IL
Posts: 1,867
Likes: 0
Received 0 Likes on 0 Posts
Default RE: which is more important

If you just upgrade to brushless all you'll need is motors and escs. If you go to LiPos you'll have the expense of the batteries, a charger and a fireproof charging container. Then there's the costly learning curve that goes with LiPos. Unlees you are extremely disciplined and well informed about (and even so) you will destroy some cells.

One more thing, since you mentioned budget, those brushless motors will last practically forever and will be around when you can afford to upgrade to a newer battery chemistry.
Walt
Old 03-07-2008, 10:36 AM
  #3  
jzrf6c
Senior Member
 
Join Date: Jun 2005
Location: Prescott Valley, AZ
Posts: 565
Likes: 0
Received 0 Likes on 0 Posts
Default RE: which is more important

If you upgrade to Lipo's go with the new A123's they will never burn your house down. They don't catch fire like the standard Lipo's. But, you will need a new charger, And you run the risk of burning out the brushed motor. LiPo's have a higher voltage than NiCa or NiMH. You need to be careful. If you upgrade to a brushless motor you can use your current batteries and charger but you'll need a new ESC. Sometime, you can get a COMBO cheaper than buying the motor and ESC separately.
Old 03-07-2008, 11:33 AM
  #4  
Walt Thyng
My Feedback: (9)
 
Join Date: Jul 2002
Location: St. Charles, IL
Posts: 1,867
Likes: 0
Received 0 Likes on 0 Posts
Default RE: which is more important

jz,
I don't quite understand the statement about burning out the brushed motor. I'm flying three birds on brushed and LiPos with no problem. I assumed that anyone wise enough to ask for advice can figure voltage.
Walt
Old 03-07-2008, 05:43 PM
  #5  
sharpshooter223
Senior Member
Thread Starter
 
Join Date: Jul 2005
Location: richland, WA
Posts: 454
Likes: 0
Received 0 Likes on 0 Posts
Default RE: which is more important

if i upgrade to brushless i will be buying a combo from hobbycity, if i upgrade to lipos ill be buying the batteries from hobbycity and the charger either from hobbycity or towerhobbies or hobbytown if they can get the charger i want.


also, what is the C value on lipo batteries?
Old 03-07-2008, 09:14 PM
  #6  
Laggard
Member
 
Join Date: Feb 2007
Location: Minneapolis, MN
Posts: 63
Likes: 0
Received 0 Likes on 0 Posts
Default RE: which is more important


ORIGINAL: sharpshooter243
also, what is the C value on lipo batteries?
It depends on the battery.

Old 03-07-2008, 09:44 PM
  #7  
sharpshooter223
Senior Member
Thread Starter
 
Join Date: Jul 2005
Location: richland, WA
Posts: 454
Likes: 0
Received 0 Likes on 0 Posts
Default RE: which is more important

yea, but what does it mean
Old 03-07-2008, 11:01 PM
  #8  
cyclops2
 
cyclops2's Avatar
 
Join Date: Dec 2005
Location: Frenchtown, NJ
Posts: 3,054
Received 6 Likes on 5 Posts
Default RE: which is more important



LIPO batteries are dangerous enough that your parents SHOULD be reading these posts with you.
It is their house and responsibilty. And yours. Do not think for a moment lipos are just a lightweight Nicad or Nickle Metal Hydride battery. They are not.

Go LIPO when you have a club you can join to teach you the right way.

Go brushless with no problems EXCEPT picking a ESC that can run on both LIPO and NIMH & Nicad. Cut off voltages are important in ESC's.

Rich
Old 03-07-2008, 11:16 PM
  #9  
sharpshooter223
Senior Member
Thread Starter
 
Join Date: Jul 2005
Location: richland, WA
Posts: 454
Likes: 0
Received 0 Likes on 0 Posts
Default RE: which is more important


ORIGINAL: cyclops2



LIPO batteries are dangerous enough that your parents SHOULD be reading these posts with you.
It is their house and responsibilty. And yours. Do not think for a moment lipos are just a lightweight Nicad or Nickle Metal Hydride battery. They are not.

Go LIPO when you have a club you can join to teach you the right way.

Go brushless with no problems EXCEPT picking a ESC that can run on both LIPO and NIMH & Nicad. Cut off voltages are important in ESC's.

Rich

yea, yea, i know all that, id still like to know what the c rating means. these very likely are my only two electric planes anyway (after college im going glow and gas, maybe hydrogen if that is a possibility in 5 or 6 years) im just trying to get myself set up to fly for a few years though.
Old 03-08-2008, 01:13 AM
  #10  
jdetray
Senior Member
 
jdetray's Avatar
 
Join Date: Dec 2004
Location: Napoleon, OH
Posts: 1,617
Likes: 0
Received 0 Likes on 0 Posts
Default RE: which is more important

A battery's C rating lets you determine the maximum current the battery can reliably provide.

You multiply the battery's capacity in Amp-hours times the C rating to get the maximum current.

Examples.

A 2100 mAh 15C battery can provide 2.1 x 15 = 31.5A.
A 2100 mAh 20C battery can provide 2.1 x 20 = 42A.
A 1500 mAh 10C battery can provide 1.5 x 10 = 15A.
etc.

It's important to know how much current a battery can provide so that you don't try to pull too much current from the battery. When you do that, a couple of things can happen. First, the battery voltage will usually drop quite a bit. Battery voltage always drops under load, but when you exceed the C rating, it drops even more. Also, when you try to draw more current from a battery than it can safely provide, the battery will usually heat up. You can permanently damage a battery this way.

The C ratings claimed by battery makers are often very optimistic, so it's reasonable to discount the ratings a bit to give yourself a safety margin.

- Jeff

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


Thread Tools
Search this Thread

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

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.