If you need assistance, please send an email to forum at 4hv dot org. To ensure your email is not marked as spam, please include the phrase "4hv help" in the subject line. You can also find assistance via IRC, at irc.shadowworld.net, room #hvcomm.
Support 4hv.org!
Donate:
4hv.org is hosted on a dedicated server. Unfortunately, this server costs and we rely on the help of site members to keep 4hv.org running. Please consider donating. We will place your name on the thanks list and you'll be helping to keep 4hv.org alive and free for everyone. Members whose names appear in red bold have donated recently. Green bold denotes those who have recently donated to keep the server carbon neutral.
Special Thanks To:
Aaron Holmes
Aaron Wheeler
Adam Horden
Alan Scrimgeour
Andre
Andrew Haynes
Anonymous000
asabase
Austin Weil
barney
Barry
Bert Hickman
Bill Kukowski
Blitzorn
Brandon Paradelas
Bruce Bowling
BubeeMike
Byong Park
Cesiumsponge
Chris F.
Chris Hooper
Corey Worthington
Derek Woodroffe
Dalus
Dan Strother
Daniel Davis
Daniel Uhrenholt
datasheetarchive
Dave Billington
Dave Marshall
David F.
Dennis Rogers
drelectrix
Dr. John Gudenas
Dr. Spark
E.TexasTesla
eastvoltresearch
Eirik Taylor
Erik Dyakov
Erlend^SE
Finn Hammer
Firebug24k
GalliumMan
Gary Peterson
George Slade
GhostNull
Gordon Mcknight
Graham Armitage
Grant
GreySoul
Henry H
IamSmooth
In memory of Leo Powning
Jacob Cash
James Howells
James Pawson
Jeff Greenfield
Jeff Thomas
Jesse Frost
Jim Mitchell
jlr134
Joe Mastroianni
John Forcina
John Oberg
John Willcutt
Jon Newcomb
klugesmith
Leslie Wright
Lutz Hoffman
Mads Barnkob
Martin King
Mats Karlsson
Matt Gibson
Matthew Guidry
mbd
Michael D'Angelo
Mikkel
mileswaldron
mister_rf
Neil Foster
Nick de Smith
Nick Soroka
nicklenorp
Nik
Norman Stanley
Patrick Coleman
Paul Brodie
Paul Jordan
Paul Montgomery
Ped
Peter Krogen
Peter Terren
PhilGood
Richard Feldman
Robert Bush
Royce Bailey
Scott Fusare
Scott Newman
smiffy
Stella
Steven Busic
Steve Conner
Steve Jones
Steve Ward
Sulaiman
Thomas Coyle
Thomas A. Wallace
Thomas W
Timo
Torch
Ulf Jonsson
vasil
Vaxian
vladi mazzilli
wastehl
Weston
William Kim
William N.
William Stehl
Wesley Venis
The aforementioned have contributed financially to the continuing triumph of 4hv.org. They are deserving of my most heartfelt thanks.
Registered Member #96
Joined: Thu Feb 09 2006, 05:37PM
Location: CI, Earth
Posts: 4061
Anything under 2.6V is basically dead, unless its a phosphate cell. I have heard of people recycling these if there is at least 3V on the cell after leaving them to sit for 24 hours unconnected to compensate for crossover current through the PCB from working cells.
They do need a proper LVC and OVC circuit, Li-Ion aren't known for being very forgiving if misused. I was planning to use a pair of MC1381's but as it turned out the phosphate cells I had were fried anyway.
Registered Member #3792
Joined: Sun Mar 27 2011, 06:07PM
Location:
Posts: 136
Also, be sure that you have the original charging - monitoring - balancing board that was used to charge the Li - ion cells because you cannot charge them like Ni - Cd, Ni - Mi or SLA batteries (they will explode if overcharged).
Registered Member #3637
Joined: Fri Jan 21 2011, 11:07PM
Location: Buffalo, NY
Posts: 1068
I've been working on a circuit using a 741 op amp or a 393 comparator... and a 555 timer as well, to make a universal battery charger, and am trying to work on getting it to ...well, work properly.
I need to add the indicator to let you know when it's charging, and when it's not. Other than that, how's it look so far? The 1 mF capacitor and the 100 ohm load is the battery.
Registered Member #3792
Joined: Sun Mar 27 2011, 06:07PM
Location:
Posts: 136
Simple Li - ion battery charger (11.1V battery pack - 3 cells in series):
Plug an unregulated 12V power supply (with a current rating equal or higher that the battery pack rating) and adjust R6 for 8.2V (4.2V per cell - the maximum voltage that Li - ion cells are rated) and R7 for 6.2V (3.1V per cell - the minimum voltage that Li - ion are rated). Then, just plug the battery pack (5 cables - plus and minus / balancer circuit).
Registered Member #3637
Joined: Fri Jan 21 2011, 11:07PM
Location: Buffalo, NY
Posts: 1068
nah. I tried to build it, and the charger would not give me any indication of it stopping at any specific voltage. It was not adjustable. I'll need to work on it again, to see if I can't get it working properly! (this was just with a capacitor on the output, to simulate a battery)
This site is powered by e107, which is released under the GNU GPL License. All work on this site, except where otherwise noted, is licensed under a Creative Commons Attribution-ShareAlike 2.5 License. By submitting any information to this site, you agree that anything submitted will be so licensed. Please read our Disclaimer and Policies page for information on your rights and responsibilities regarding this site.
How to revive Li-ion batteries...
