HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old Feb 15, 2012, 07:17 PM
Suspended Account
Joined Nov 2011
206 Posts
Addendum: this thing works great! It tracks my PL 8 very well.

Second addendum: the design is well thought out, and absolutely intuitive.
ReddiK is offline Find More Posts by ReddiK
Last edited by ReddiK; Feb 16, 2012 at 08:21 PM.
Reply With Quote  (Disabled)
Sign up now
to remove ads between posts
Old Feb 21, 2012, 07:23 AM
Registered User
United States, PA, Clarks Summit
Joined Jan 2007
11 Posts
Wayne, Just received my ESR meter from F3A Unlimited. Been reading this thread for over as year. It is great -- started to get used to using it and very excited to have your meter. Continued success Stan
Abington Flyer is offline Find More Posts by Abington Flyer
Reply With Quote
Old Feb 21, 2012, 03:37 PM
Registered User
Rugby, UK
Joined Feb 2007
876 Posts
Quote:
Originally Posted by Abington Flyer View Post
Wayne, Just received my ESR meter from F3A Unlimited. Been reading this thread for over as year. It is great -- started to get used to using it and very excited to have your meter. Continued success Stan
Stan,

Thanks for feedback. Hope you find it useful both in sorting out the best lipos and in monitoring the condition of your existing ones.

Feeding results into Mark Forsyth's thread (Link below) helps build up a data bank of lipo's real capabilities as distinct from maker's claims.

http://www.rcgroups.com/forums/showt...1#post20484169

Wayne
Wayne Giles is offline Find More Posts by Wayne Giles
Reply With Quote
Old Feb 27, 2012, 01:10 AM
Nemo in a blender
Connexxion's Avatar
The Netherlands-Amsterdam
Joined Mar 2007
940 Posts
Wayne,

what values should we look for?

I.e. what IR value per cell (+/-)would you call:
-excellent
-good
-poor
-dead

And what temperature should we do the measurements?

cnnxxn
Connexxion is offline Find More Posts by Connexxion
Reply With Quote
Old Feb 27, 2012, 05:18 AM
Southern Pride
everydayflyer's Avatar
Haralson County GA. USA
Joined Oct 2004
34,812 Posts
Deleted my post will leave for Wyne to answer.

Charles
everydayflyer is offline Find More Posts by everydayflyer
Reply With Quote
Old Feb 27, 2012, 05:36 AM
Registered User
Rugby, UK
Joined Feb 2007
876 Posts
Quote:
Originally Posted by Connexxion View Post
Wayne,

what values should we look for?

I.e. what IR value per cell (+/-)would you call:
-excellent
-good
-poor
-dead

And what temperature should we do the measurements?

cnnxxn
Hi Connxxn,

Obviously we are looking for the lowest value of IR for the best results; ie lowest voltage drop and coolest lipo.
It is difficult to just spout numbers as it is a function of the cell capacity and seems a linear function. Thus a very good 2200 cell is about 3-4 milliohms at 25deg.cent whilst an average is about 6 - 7milliohms and a poor one 8+.
So for smaller or larger cell capacities you should multiply these numbers by 2200 and divide the result by the cell capacity in mAh.
This only a crude rule of thumb and lots of people will disagree with my figures.

There was a good discussion triggered by Mark Forsyth's suggestion of replacing the completely discredited "C" ratings with a Figure of Merit based on the IR values. It is at:
http://www.rcgroups.com/forums/showthread.php?t=1392662

John Julian has also posted a discussion thread in which there is load of useful information at :
http://www.rcgroups.com/forums/showthread.php?t=1577989

Mark has a calculator for determining REAL "C" values from IR figures at:
http://www.rcgroups.com/forums/showt...1#post20484169

I must say that I am surprised that these have not attracted a lot more interest by modellers who wish to find out the real capablities of their lipos rather than believing the cynical "C" ratings claimed by dishonest marketeers.

Perhaps people are put off a little by the amount of information there and the effort to flog through it all, but nothing is acheived without some effort and you can jump straight to the calculator if you wish.

Anybody with a decent charger capable of reading IR, or a meter can now get so much nearer to the truth about their lipos with just a little effort.

Re your question about temperature, I used to use 25degC but am now changing to 22degC to fall in line with the calculator. Remember it is most important to allow the pack to settle for several hours in a 22degC ambient.

Wayne
Wayne Giles is offline Find More Posts by Wayne Giles
Reply With Quote
Old Feb 28, 2012, 05:37 AM
Nemo in a blender
Connexxion's Avatar
The Netherlands-Amsterdam
Joined Mar 2007
940 Posts
Thanks for the effort you took to answer my questions.

I received the ESR and plan to use it on every single lipo that comes across my way,but not until I fully understand what I'm doing and what I need to look for.

I was one of the people that used to look at C-rates only.
You and other guys here on RCG opened my eyes and I'm much wiser now.

It's people like you that make this hobby so much more interesting.
People that are willing to share their knowledge they gained over years with others and don't mind to put hours and hours in just answering questions asked by unknown people they never met or will meet.

Sometimes I just wish I could shake your hand and tell you in person what I just wrote/typed.

So thank you a thousand times Wayne!

Abdel
Connexxion is offline Find More Posts by Connexxion
Reply With Quote
Old Feb 28, 2012, 07:10 AM
Registered User
Mikecam's Avatar
Canada, MB, Winnipeg
Joined Apr 2008
939 Posts
Connexxion just summed it up better then I ever could!!!!

Just want to say thanks to Wayne for a great product and tool for us fellow modelers. I have an email into F3A Unlimited for a shipping quote for us Canucks that would like this great instrument. Thanks again Wayne.
Mikecam is offline Find More Posts by Mikecam
Reply With Quote
Old Feb 28, 2012, 03:14 PM
Registered User
Rugby, UK
Joined Feb 2007
876 Posts
Abdel & Mike,

Thanks very much for those kind words. I am somewhat embarrassed as although I realise the information is useful to some people, the actual motive is selfish in that it springs from a lifelong interest in power electronics. I enjoy making the units and whilst just stuffing PCBs can become a pain, I get a little surge of satisfaction every time one works and calibrates ok on test. So I am a lucky anorak, having a hobby which more than breaks even!
There are many other people who pass on useful info on the forum, such as Charles, Mark Forsyth, John Julian and many others, who are also really anoraks, just like me , but probably don't like the description. To me the word "Anorak" just means an enthusiast with specialist knowledge.

Wayne
Wayne Giles is offline Find More Posts by Wayne Giles
Reply With Quote
Old Feb 28, 2012, 03:38 PM
ancora imparo
jj604's Avatar
Melbourne, Australia
Joined Jul 2005
6,611 Posts
For anyone who hasn't a clue what Wayne is talking about there is a guide to the peculiarities of British English usage - anorak - here:

http://www.guardian.co.uk/notesandqu...-19185,00.html

jj604 is offline Find More Posts by jj604
Reply With Quote
Old Feb 28, 2012, 03:54 PM
Registered User
Rugby, UK
Joined Feb 2007
876 Posts
Quote:
Originally Posted by jj604 View Post
For anyone who hasn't a clue what Wayne is talking about there is a guide to the peculiarities of British English usage - anorak - here:

http://www.guardian.co.uk/notesandqu...-19185,00.html

Thanks John. You seem to have an obsessive knowledge of the English language so my inclusion of you in the list was justified!

Wayne
Wayne Giles is offline Find More Posts by Wayne Giles
Reply With Quote
Old Feb 28, 2012, 06:58 PM
Registered User
Mikecam's Avatar
Canada, MB, Winnipeg
Joined Apr 2008
939 Posts
Just want to say thanks to Chris Moon from http://www.f3aunlimited.com/webstore...roducts_id=572 who took care of me and my order to Canada. Any other Canucks out there Chris is very helpful and the $7 shipping to Canada is very fair.
If he could ship it as "warranty" it would make me over the MOON. LOL Just a little pun for fun.

Thanks again Wayne, looking forward to receiving my new toy and being the envy of my electric flying cohorts.
Mikecam is offline Find More Posts by Mikecam
Last edited by Mikecam; Feb 14, 2013 at 11:26 AM. Reason: Fixed link
Reply With Quote
Old Mar 23, 2012, 04:09 AM
Registered User
Joined Mar 2012
58 Posts
Hi Wayne,

First post, first request!

Do you have an ESR meter available please? Thank you.
Andy from Sandy is offline Find More Posts by Andy from Sandy
Last edited by Andy from Sandy; Mar 23, 2012 at 04:15 AM.
Reply With Quote
Old Mar 23, 2012, 04:16 AM
Registered User
Rugby, UK
Joined Feb 2007
876 Posts
Quote:
Originally Posted by Andy from Sandy View Post
Hi Wayne,

First post, first request!

Do you have an ESR meter available please. Thank you.
Andy,

Yes, I am just making a batch of 12 of which there are 5 available. They should be finished within about a week, so if you send me a PM I will give you my e-mail address for Paypal.
Thanks for enquiry,

Wayne
Wayne Giles is offline Find More Posts by Wayne Giles
Reply With Quote
Old Mar 23, 2012, 04:30 AM
Registered User
Joined Mar 2012
58 Posts
Excellent, thank you. PM sent.
Andy from Sandy is offline Find More Posts by Andy from Sandy
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Discussion Best fo the West Jets Schwemmer Inland Slope Rebels 0 Oct 14, 2010 05:02 PM
Discussion Motor fo UH Haoye EDF Ducted Fan Unit 7 Blade 3.5inch RJPIoW Electric Ducted Fan Jet Talk 1 Sep 08, 2010 12:05 PM
Question New Low IR Lipos Cells nxtdoor High Performance 75 Sep 06, 2009 04:47 PM
Discussion ESR meter to test Nicad/NiMH ?? 1101 DIY Electronics 3 Jun 15, 2009 04:08 AM