Welcome to the WIMAC forums.

You are currently viewing our site as a guest which gives you limited access to view most discussions and access our other features. By joining our free community you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is fast, simple and absolutely free so please, join our community today!

If you have any problems with the registration process or your account login, please contact us.

Go Back   WIMAC > General > General Discussion

General Discussion A place to talk about anything R/C or otherwise.

Reply
 
Thread Tools Display Modes
  #1  
Old 2010-08-02
Hadi's Avatar
Hadi Hadi is offline
Non-WIMAC Member
First Name: Hadi
Last Name: Alaee
MAAC Number: 82265
WIMAC WINGS: Solo Planes
 
Join Date: Mar 2010
Posts: 104
Hadi is on a distinguished road
lipo batteries

I've been trying to understand the concept of Lipo Batteries but there is still something that I don't understand:

What is the difference between the Lipo 11.4V 1300mAh vs 1800mAh?

Do I get a higher power or flying time with higher mAh?

Ps. is it safe to buy Lipos from Hobbyking?
Reply With Quote
  #2  
Old 2010-08-02
xed's Avatar
xed xed is offline
Administrator
First Name: Greg
Last Name: Patterson
MAAC Number: 71347
WIMAC WINGS: Solo Planes
 
Join Date: Jan 2007
Posts: 1,353
xed is on a distinguished road
Send a message via MSN to xed
More mAh = more capacity = more flying time.

More voltage = more power.
Reply With Quote
  #3  
Old 2010-08-02
mitea_dan's Avatar
mitea_dan mitea_dan is offline
Club Member
First Name: Theodor-Dan
Last Name: Mitea
MAAC Number: 77638
WIMAC WINGS: Solo Planes
 
Join Date: Jun 2007
Posts: 736
mitea_dan is on a distinguished road
But it also means it’s heavier, and so the flight time isn’t that much longer, at least not proportional to the battery’s capacity.
In my opinion, the best would be the battery that lets you fly between 10 and 15 mins.

Last edited by mitea_dan; 2010-08-02 at 10:13 PM.
Reply With Quote
  #4  
Old 2010-08-02
Burning Head's Avatar
Burning Head Burning Head is offline
Non-WIMAC Member
First Name: Richard
Last Name: Sabourin
MAAC Number: 79332
WIMAC WINGS: Instructor Plane
 
Join Date: Jun 2008
Posts: 4,425
Burning Head is on a distinguished road
15 to 20C max its ok for your trainer Hadi
Reply With Quote
  #5  
Old 2010-08-03
RichR's Avatar
RichR RichR is offline
Non-WIMAC Member
First Name: Rich
Last Name: Rambahal
MAAC Number: 80960
WIMAC WINGS: Instructor
 
Join Date: Feb 2007
Posts: 496
RichR is on a distinguished road
Hi Hadi,

Also keep in mind that greater capacity "Higher mAh" can supply you with greater sustained amps while maintaining a proper voltage level, meaning (In theory):

(mAh of lipo * C Value)/1000 = Continuous discharge Amps

A 20C 1300mAh pack = 20C *1.3Amps(1300mAh) = 26 Continuous Amps
A 20C 1800mAh pack = 20C *1.8Amps(1800mAh) = 36 Continuous Amps

Be sure to check your electric motor specifications and choose a lipo pack that can supply the needed amps. Remember, higher C ratings are good for high-power applications, however, they are simply overkill for many trainer type applications. Like it has been mentionned, the higher the C-rating the heavier an equivalent pack becomes! Let us imagine a 45C 1800mAh pack:

45C *1.8Amps = 81 Continuous Amps!!!!!!!!!!! (So, like BurningHead said, keep the C-rating as well as the capacity in mind. And remember, a higher capacity (meaning greater mAh)lipo will also maintain a higher voltage under load throughout your entire flight versus an equivalent voltage lower capacity lipo pack which in turn means more power because Voltage*Amps=Watts and the more watts, the more power. Watch the AUW of the aircraft, and find a suitable balance, meaning a battery that can supply the amps without going overboard with the C-rating and give you tolerable flight times without sacrificing weight (Although a bit of weight is good on windy days!). There is a lot more to this, anyhow...Hope that helps! Good Luck

Last edited by RichR; 2010-08-03 at 06:10 AM.
Reply With Quote
  #6  
Old 2010-08-15
Hadi's Avatar
Hadi Hadi is offline
Non-WIMAC Member
First Name: Hadi
Last Name: Alaee
MAAC Number: 82265
WIMAC WINGS: Solo Planes
 
Join Date: Mar 2010
Posts: 104
Hadi is on a distinguished road
One more question: What is the best and most econmic charger I could buy? right now I'm using the Great Planes 3S LiPo Balancing Charger which came with my SkyFly Max,

http://www3.towerhobbies.com/cgi-bin...&I=LXVZZ3&P=ML

It charges in a current of 800mA maximum! but it would take a long time to charge my two batteries "1800mA" because it charges only One at a time,.

Is it a good Idea to buy another one of these chargers for $25 or I should go for a better one that charges faster and easier!

tnx
Reply With Quote
  #7  
Old 2010-08-15
Burning Head's Avatar
Burning Head Burning Head is offline
Non-WIMAC Member
First Name: Richard
Last Name: Sabourin
MAAC Number: 79332
WIMAC WINGS: Instructor Plane
 
Join Date: Jun 2008
Posts: 4,425
Burning Head is on a distinguished road
Invest in a good trainer Hadi, you will fly and lurn more my friend then with your Sky fly.
Reply With Quote
  #8  
Old 2010-08-16
RichR's Avatar
RichR RichR is offline
Non-WIMAC Member
First Name: Rich
Last Name: Rambahal
MAAC Number: 80960
WIMAC WINGS: Instructor
 
Join Date: Feb 2007
Posts: 496
RichR is on a distinguished road
...

Hi Hadi,

Don't waste your money on buying another Great planes 'wall adapter' charger, simply buy an Accucel 6 for $22.99 + Shipping from Hobbyking. A lot of people I know use them with great success. It has the following specs:

Features;
Microprocessor controlled
Delta-peak sensitivity (NiMH/NiCd)
Individual cell balancing
Li-ion, LiPo and LiFe capable
Ni-Cd and NiMH capable
Large range of charge currents
Store function, allows safe storage current
Time limit function
Input voltage monitoring. (Protects car batteries at the field)
Data storage (Store up to 5 packs in memory)
Battery break in and cycling.

Spec.
Input Voltage: 11~17v
Circuit power: Max Charge: 50W / Max Discharge: 5W
Charge Current Range: .1~6.0A
Ni-MH/NiCd cells: 1~15
Li-ion/Poly cells: 1~6
Pb battery voltage: 2~20v
Weight: 355g

This charger has a JST-XH charge plug, which makes it compatible with Zippy, HXT, TURNIGY and any pack with a JST-XH adapter.
Reply With Quote
  #9  
Old 2010-08-16
RichR's Avatar
RichR RichR is offline
Non-WIMAC Member
First Name: Rich
Last Name: Rambahal
MAAC Number: 80960
WIMAC WINGS: Instructor
 
Join Date: Feb 2007
Posts: 496
RichR is on a distinguished road
FYI

Btw,

You will also need a power supply to feed the charger, you can use an old PC power supply (try not to electrocute yourself...lol) or an old wall adapter that supplies 12v in excess of 6 Amps (if you intend on charging packs up to 6000mAh, which I doubt!)

Later

Last edited by RichR; 2010-08-16 at 01:50 AM.
Reply With Quote
  #10  
Old 2010-08-16
Mick's Avatar
Mick Mick is offline
Non-WIMAC Member
First Name: Mick
Last Name: Forey
MAAC Number: 78579
WIMAC WINGS: Instructor
 
Join Date: Feb 2008
Posts: 862
Mick is on a distinguished road
This charger would be limited by the total power capacity of 50W. This is great for small batteries ie low voltage or low capacity but if you intend to work up to medium to large batteries 4-6S at 3000mAh+ then I recommend a 150-200W charger. For example:

http://www.hobbycity.com/hobbycity/s...r_&_discharger
Reply With Quote
Reply

Bookmarks


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Display Modes

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

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
For all LIPO users... Elgreco General Discussion 18 2009-07-16 08:16 AM
Lipo pack balancing... beto9 General Discussion 4 2009-05-21 07:49 AM


All times are GMT -4. The time now is 10:21 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.