HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old Jan 10, 2013, 05:50 AM
Registered User
Mike20's Avatar
Joined Sep 2012
544 Posts
Oh I don't know if I did it on the bench I basically just put the plane on my bed (with everything in it edf unit, ESC, Rx) hooked my power analyzer up to the ESC and then hooked the battery up to the power analyzer. I made sure there was nothing obstructing the airflow. Is that what you mean by a bench test? Or are you talking about with the edf unit out of the plane testing it?
Mike20 is offline Find More Posts by Mike20
Reply With Quote
Sign up now
to remove ads between posts
Old Jan 10, 2013, 08:32 AM
Registered User
Joined Jul 2012
16 Posts
there is a lot one man can do with 50mm jets ;-)

http://www.rcgroups.com/forums/showthread.php?t=1806101

regards

swissflying
swissflying is offline Find More Posts by swissflying
Reply With Quote
Old Jan 10, 2013, 08:53 AM
Registered User
United States, FL, Altamonte Springs
Joined Jun 2012
1,585 Posts
Quote:
Originally Posted by Mike20 View Post
Is Gforce a good battery
+1 for GForce lipos from ValueHobby. Haven't had a failure yet. OTOH, I'm trying to warranty a 4s 2200mah from HobbyKing currently.
voxel is offline Find More Posts by voxel
Reply With Quote
Old Jan 10, 2013, 10:33 AM
chuck
santa barbara, CA
Joined May 2009
4,187 Posts
Quote:
Originally Posted by voxel View Post
+1 for GForce lipos from ValueHobby. Haven't had a failure yet. OTOH, I'm trying to warranty a 4s 2200mah from HobbyKing currently.
what h/k battery?
chas650r is offline Find More Posts by chas650r
Reply With Quote
Old Jan 10, 2013, 10:45 AM
Has Sloped Off
dav3uk's Avatar
Uk South Wales
Joined Aug 2009
2,311 Posts
Quote:
Originally Posted by Mike20 View Post
Oh I don't know if I did it on the bench I basically just put the plane on my bed (with everything in it edf unit, ESC, Rx) hooked my power analyzer up to the ESC and then hooked the battery up to the power analyzer. I made sure there was nothing obstructing the airflow. Is that what you mean by a bench test? Or are you talking about with the edf unit out of the plane testing it?
No plane on the bench just means not in the air actually flying, some people have the facility to monitor volts and amps in flight, new TX like the DX8 have this ability. Most people just test on the ground static and then deduct some to get a good idea of what the in flight numbers will be.

Dave
dav3uk is offline Find More Posts by dav3uk
Reply With Quote
Old Jan 10, 2013, 11:01 AM
chuck
santa barbara, CA
Joined May 2009
4,187 Posts
fwiw, my tests have shown very little unloading w/ edf's, they just dont bite the air that well ever. large props will grab enough air on sleek airframes to push the airplane close to pitch speed , hence to unloading. not so in edf's , you may have a eflux speed of 200mph and only see a little over 100 , lots of slipping going on .

not to say there is none , but a few % seems about it.

chuck.
chas650r is offline Find More Posts by chas650r
Reply With Quote
Old Jan 10, 2013, 11:48 AM
Wonderfully Wicked
The Don's Avatar
Willoughby, Ohio
Joined Jan 2002
13,158 Posts
Quote:
Originally Posted by chas650r View Post
fwiw, my tests have shown very little unloading w/ edf's
My Eagletree logger has shown essentially no unloading on EDFs. The watt "reduction" I did see was not a load reduction, but in reality the lipo dropping voltage as it was being discharged. If there was true unloading then watts will go down and volts will go up. My inflight test was to fly flat and level full throttle to get some in flight level data, then pull up elevator and climb straight up until you ran out of vertical climb (full stop nose up is the same as a "bench test", if there was loading then the longer the vertical climb then you shoudl see that and it would peak when you stop. I never saw it. I could only tell I was at full stop when by my Eagletree data showed no airspeed on the pitot tube.

Don
The Don is online now Find More Posts by The Don
RCG Plus Member
Last edited by The Don; Jan 10, 2013 at 11:55 AM.
Reply With Quote
Old Jan 10, 2013, 12:25 PM
Registered User
United States, FL, Altamonte Springs
Joined Jun 2012
1,585 Posts
Quote:
Originally Posted by chas650r View Post
what h/k battery?
Bought a bunch of these:

http://www.hobbyking.com/hobbyking/s...dProduct=16204

One was puffy and hot after a short run. I need to further test the rest before using them again.
voxel is offline Find More Posts by voxel
Reply With Quote
Old Jan 10, 2013, 01:17 PM
Registered User
gooniac33's Avatar
Sunnyvale
Joined Feb 2009
5,070 Posts
Quote:
Originally Posted by voxel View Post
Bought a bunch of these:

http://www.hobbyking.com/hobbyking/s...dProduct=16204

One was puffy and hot after a short run. I need to further test the rest before using them again.
Never push a new battery. You need to get at least 5-10 cycles of light duty at the very least before you really push it. But you really should go about 20 to get the most out of it. You can damage a pack by pushing it too hard too soon. New packs will have a pretty high internal resistance at first which leads to them heating up under load...
gooniac33 is online now Find More Posts by gooniac33
Reply With Quote
Old Jan 10, 2013, 02:43 PM
ICrashRCs
United States, TN, Memphis
Joined Jun 2011
1,196 Posts
@Nigel
Think I'm going with this set:
Would one of these be correct?
3-0.5, 3-0.6
http://www.harborfreight.com/40-piec...set-39384.html

Like you say, it's good to have a set here anyway.
IFlyRCs is offline Find More Posts by IFlyRCs
Reply With Quote
Old Jan 10, 2013, 03:26 PM
chuck
santa barbara, CA
Joined May 2009
4,187 Posts
Quote:
Originally Posted by gooniac33 View Post
Never push a new battery. You need to get at least 5-10 cycles of light duty at the very least before you really push it. But you really should go about 20 to get the most out of it. You can damage a pack by pushing it too hard too soon. New packs will have a pretty high internal resistance at first which leads to them heating up under load...
do u have test data to back that up? not saying u dont and i take it easy on the new ones but i have not seen the ir go down in my tests. interesting.

chuck.
chas650r is offline Find More Posts by chas650r
Reply With Quote
Old Jan 10, 2013, 04:21 PM
Registered User
gooniac33's Avatar
Sunnyvale
Joined Feb 2009
5,070 Posts
Quote:
Originally Posted by chas650r View Post
do u have test data to back that up? not saying u dont and i take it easy on the new ones but i have not seen the ir go down in my tests. interesting.

chuck.
I am sure that I can find it if I look. But I work with batteries for a living and the same rules apply to the small lipos we use. Unless I have read it wrong.....
gooniac33 is online now Find More Posts by gooniac33
Reply With Quote
Old Jan 10, 2013, 04:31 PM
Registered User
gooniac33's Avatar
Sunnyvale
Joined Feb 2009
5,070 Posts
Here it is...

Hyperion:
Break-In Procedure - Hyperion G3 LiPo are robust and do not need a complicated break-in procedure. We recommend that the first 5 uses are limited to 3C charge rates, and that pilots use throttle management to avoid long periods of max-rate discharge for those first 5 flights. Note also the other care suggestions below. Those apply pretty generally to any LiPo pack, not just Hyperion G3...
http://media.hyperion.hk/dn/g3lipo/

Thunder Power:
First few Flights Thunder Power recommends no more than 3-5C average discharge for breaking in new packs. Also be extremely careful not to over discharge new packs (Packs should NEVER be over discharged at any time, but over discharging on the first flight will ruin the battery permanently before you are able to enjoy it. See “Caring for Battery” below).
http://thunderpowerrc.com/PDF/THPSafetyWarnings.pdf
gooniac33 is online now Find More Posts by gooniac33
Reply With Quote
Old Jan 10, 2013, 05:12 PM
Registered User
United States, FL, Altamonte Springs
Joined Jun 2012
1,585 Posts
Quote:
Originally Posted by gooniac33 View Post
Never push a new battery. You need to get at least 5-10 cycles of light duty at the very least before you really push it. But you really should go about 20 to get the most out of it. You can damage a pack by pushing it too hard too soon. New packs will have a pretty high internal resistance at first which leads to them heating up under load...
It's a bit OT, but these lipos were used on a Dynam Sbach which I didn't WOT much (2nd flight! too scared!)

My Turnigy 4s 850mah lipos for my Screamer are beginning to puff after a few runs. There's no airflow over it and I tend to WOT it in large 15-30 second chunks. A 25+ mpg gust flipped it over on the field table today and dented one of the vert stabs. Gah. It's survived all sorts of crazy grass landings and remain pristined and gets nicked up by this!!!? Oh well...
voxel is offline Find More Posts by voxel
Reply With Quote
Old Jan 10, 2013, 11:34 PM
Registered User
gooniac33's Avatar
Sunnyvale
Joined Feb 2009
5,070 Posts
Quote:
Originally Posted by voxel View Post
It's a bit OT, but these lipos were used on a Dynam Sbach which I didn't WOT much (2nd flight! too scared!)

My Turnigy 4s 850mah lipos for my Screamer are beginning to puff after a few runs. There's no airflow over it and I tend to WOT it in large 15-30 second chunks. A 25+ mpg gust flipped it over on the field table today and dented one of the vert stabs. Gah. It's survived all sorts of crazy grass landings and remain pristined and gets nicked up by this!!!? Oh well...
It's not the airflow. Puffing happens internally and it does have a lot to do with how you are discharging the battery. As I said in the first post, it's best to go easy on it for the first 5-10 flights. What is happening to you now is a direct result of over doing it when the battery is new.
gooniac33 is online now Find More Posts by gooniac33
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Discussion Adelaide & SA flying & chat #2 Zootster Australia 20930 Today 06:28 AM
Help! Where can I buy Genkem Nova 27 in SA? MegaTesla South Africa 2 May 14, 2011 03:25 PM
Discussion SAL-SA Glider in Gobi dune romanticus Slope 11 Nov 30, 2010 10:40 PM
Question SA 2010-02 Castle ICE 100 "failed cut off" ?? LandCruiser Castle Creations 2 Oct 19, 2010 11:07 PM
T-33 Spring-air minis HW609 Derrek Curtis Electric Ducted Fan Jet Talk 3 Apr 25, 2001 03:42 PM