HobbyKing.com New Products Flash Sale
Closed Thread
Thread Tools
Old Mar 16, 2005, 12:13 PM
Registered User
Joined Jan 2002
6,587 Posts
Woo is good for laughs at PICNICS ...
RD Blakeslee is offline Find More Posts by RD Blakeslee
Sign up now
to remove ads between posts
Old Mar 16, 2005, 12:19 PM
Permanently Banned
San Jose Ca / RSA flyer
Joined May 2003
8,030 Posts
Greatest Show in the World

Rd

U should come over and see the " FLYING CIRCUS" every weekend here at RSA next time U visit CA. I have a plane that U can finsh a RACE with, come on over and try it.
hall woo is offline Find More Posts by hall woo
Old Mar 16, 2005, 12:23 PM
Repair Specialist
Ken-Ohki's Avatar
Someplace in Maine
Joined Jan 2004
978 Posts
ok, at the risk of showing my ignorance, and perhaps hijacking the thread.

"WHY" wont 2 cells in a pack equalize? if one is 3.3 and one is 3.5. Why wont the 3.5 pack charge the 3.3 pack netting 3.4 volts a cell?? ( wile slow charging )

I have watched Nicads and nimhi's do this with my meter, why dont lipos?

And wile im asking and showing my ignorance... Just how does 1 cell give more then another cell causing the imbalance in the first place.


Ken-Ohki
Ken-Ohki is offline Find More Posts by Ken-Ohki
Old Mar 16, 2005, 12:27 PM
Registered User
Toms River Rj Miller, New Jersey (excl EWR), United States
Joined May 2003
318 Posts
Only cells in PARALLEL equalize each other. Variations in internal resistance [I am told] cause cells to vary when charged in series.
rcflyrdon is offline Find More Posts by rcflyrdon
Old Mar 16, 2005, 12:35 PM
Space Coast USA
hoppy's Avatar
Space Coast
Joined Oct 2000
21,107 Posts
[QUOTE=Ken-Ohki]ok, at the risk of showing my ignorance, and perhaps hijacking the thread.


And wile im asking and showing my ignorance... Just how does 1 cell give more then another cell causing the imbalance in the first place.
If you really want to know, read this: http://www.analogzone.com/pwrt0207.pdf

I have watched Nicads and nimhi's do this with my meter, why dont lipos?
NiCd and NiMH cells can dissapate excess charge energy by converting it to heat. Lipo's when subjected to excess voltages chemically and irreversibly degrade.
hoppy is offline Find More Posts by hoppy
Old Mar 16, 2005, 12:38 PM
Permanently Banned
San Jose Ca / RSA flyer
Joined May 2003
8,030 Posts
Learn How to Slow Charge Using AF 109

Ken

When normal LIPO packs have been slighly over-stress, time is the magic ingredient to restore the cell back to its normal SOC ( stable open circuit ) voltage.

Further 1C fast charging will create more VOLTAGE GAP between cells and impede a normal fast charge 1C full charge. I have monitored this problem on the TAPs

A SLOW CHARGE at 50 ma -100ma shows a lesser " VOLTAGE GAP " level

But if U already have a defective overheated leaky tab cell, then no amount of any kind of charge gonna do anything.

That's why if a pack won't SLOW CHARGE, then its not normal. A good pack will pass a 3 " TIMEOUT" slow charge test using AF 109 in 3 hours

U should review my thread on Setting AF 10-9 for 9 hour Charge
hall woo is offline Find More Posts by hall woo
Old Mar 16, 2005, 12:49 PM
Southern Pride
everydayflyer's Avatar
Haralson County GA. USA
Joined Oct 2004
34,833 Posts
Yes slow charging my Li Poly batteries at between 0.2a and 0.3a (200-300mAh) does balance them to within ,closer than I can measure.

However there is a trick(?) to doing this. You must use some type of balancers which are connected to each cell of group of parallel connected cells.



http://www.rcgroups.com/forums/showp...9&postcount=40
Charles
everydayflyer is offline Find More Posts by everydayflyer
Last edited by everydayflyer; Mar 16, 2005 at 01:27 PM.
Old Mar 16, 2005, 12:59 PM
Permanently Banned
San Jose Ca / RSA flyer
Joined May 2003
8,030 Posts
Astrobob and I don't use any active balancing circuits, just the RIGHT current level
hall woo is offline Find More Posts by hall woo
Old Mar 16, 2005, 01:09 PM
Crash Master
Gene Bond's Avatar
Indianapolis, IN
Joined Sep 2001
16,632 Posts
What Hoppy said.
Gene Bond is offline Find More Posts by Gene Bond
Old Mar 16, 2005, 01:17 PM
Southern Pride
everydayflyer's Avatar
Haralson County GA. USA
Joined Oct 2004
34,833 Posts
Quote:
Originally Posted by hall woo
Astrobob and I don't use any active balancing circuits, just the RIGHT current level
Astrobob Mr. Astro Flight ,Bob Boucher has never stated to the best of my knowledge that slow charging a LIPoly pack of series connected cells will balance them. You have been asked to supply proof of this numerous times. Where is the link to the post where Bob made such a statement. I have purchased and reads his books, I own several of his chargers, many of his Cobalt motors, and even a speed control or or two. I am very familiar with the vast knowledge he posses. In my eyes he is the father of electric flight.
It is very unfair and misleading to give the impression that he supports your notions.
Many of us here know about you and your alter ego but you could lead some newbie astray.

Charles
everydayflyer is offline Find More Posts by everydayflyer
Old Mar 16, 2005, 01:41 PM
Permanently Banned
San Jose Ca / RSA flyer
Joined May 2003
8,030 Posts
I was with him at Magnolia High School Electric Fly Event back in the 80s when he was developing COBALT motors and everyone was using ferrite 05 motors

I don't know if Bob ever said SLOW CHARGING balanced packs, only that we were able to restore packs back to normalcy SLOW CHARGING

IMHO, I don't think U need to worry about newbies understanding " CLAMPED VOLTAGE" since they probably don't even know how to use a DVM and how to check it for calibration.
hall woo is offline Find More Posts by hall woo
Old Mar 16, 2005, 02:09 PM
Registered User
Walled Lake, MI, USA
Joined Feb 2000
11,182 Posts
Quote:
Originally Posted by hall woo
I don't know if Bob ever said SLOW CHARGING balanced packs, only that we were able to restore packs back to normalcy SLOW CHARGING
It's nice that you are finally starting to be more clear about this. To be more specific, astrobob only said that he restored a pack that had been discharged to less than 3.0V per cell by slow charging it until it was above 3.0V per cell. Balance was never mentioned.
Dave Hederich is offline Find More Posts by Dave Hederich
Old Mar 16, 2005, 02:26 PM
luc
I plant balsa sticks too
luc's Avatar
France
Joined Feb 2000
3,585 Posts
yep, this is a classic procedure,...nothing to do with imbalance....
luc is offline Find More Posts by luc
Old Mar 16, 2005, 03:40 PM
Flying motor mount master
fly_boy99's Avatar
San Jose, California, United States
Joined Oct 2004
8,745 Posts
Hall-

If you only fly your "CIRCUS" on weekends then I'll avoid RSA on weekends for now. Heck it's a zoo anyway and you can have it!!!

Who knows there might be a lipo "FIRE" act in your "CIRCUS"...

lol,
fb


Quote:
Originally Posted by hall woo
I was with him at Magnolia High School Electric Fly Event back in the 80s when he was developing COBALT motors and everyone was using ferrite 05 motors

I don't know if Bob ever said SLOW CHARGING balanced packs, only that we were able to restore packs back to normalcy SLOW CHARGING

IMHO, I don't think U need to worry about newbies understanding " CLAMPED VOLTAGE" since they probably don't even know how to use a DVM and how to check it for calibration.
fly_boy99 is offline Find More Posts by fly_boy99
Old Mar 16, 2005, 07:18 PM
Permanently Banned
Larry3215's Avatar
Gig Harbor, Washington, United States
Joined Sep 2003
8,434 Posts
Just incase there is any doubt in anyones mind - I would highly recomend you take anything hall woo (or rcguy01 = same person) with a HUGE grain of salt!

Infact mabey even more than one or two grains

Larry
Larry3215 is offline Find More Posts by Larry3215
Closed Thread


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Discussion Does slow charge lipo = balanced pack? lammy1000 Batteries and Chargers 61 Jan 04, 2007 04:06 AM
How long does it take to charge up your micros? Ni-Mh? Lipo? gotime242 Micro Helis 6 Oct 20, 2005 09:44 AM
Yippee! LiPo Slow Charge Ė whatís that? RC Man Batteries and Chargers 12 Jul 28, 2005 11:11 AM
Question How long does it take to charge your LiPo? neuroblade Batteries and Chargers 24 Jul 26, 2005 02:24 PM
Does Orbit charge Lipo's? TheTick Batteries and Chargers 3 Aug 22, 2004 08:55 PM