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Old Jan 14, 2011, 04:05 PM
Chuck Norris can drown a fish.
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United States, CA, Loyalton
Joined Dec 2003
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Wait for it...
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Old Mar 08, 2011, 05:06 AM
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overedline's Avatar
Chino Hills, CA
Joined Dec 2006
453 Posts
Quote:
Originally Posted by hallstudio View Post
you need a nicd or nimh charger and do a slow charge .3C untill you hit 3.25 volts per cell then charge with the ballance charger.
Can I do this with one of those AA nimh chargers from wal-mart? I have one that charges 4 AA batteries in about 8 hours. I am thinking I can wire it up so I can get it to charge a 3.7 volt lipo. I would connect three AA (1.5v) positive terminals in parallel and three negative terminals in parallel and that would be like charging a 4.5v battery. The fully charged state of the lipo is 4.2v.

Will this work?
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Old Mar 08, 2011, 05:30 AM
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Australia
Joined Nov 2010
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Quote:
Originally Posted by overedline View Post
Can I do this with one of those AA nimh chargers from wal-mart? I have one that charges 4 AA batteries in about 8 hours. I am thinking I can wire it up so I can get it to charge a 3.7 volt lipo. I would connect three AA (1.5v) positive terminals in parallel and three negative terminals in parallel and that would be like charging a 4.5v battery. The fully charged state of the lipo is 4.2v.

Will this work?
NO!

You need to use a charger where you can get a read out of the voltage and miliamps being delivered to the pack. Don't cut corners here as the results will not be pretty. Do ant charging outside away from combustable items just incase. As an example of what I mean, go to hobbyking.com and search for an accucel 6 charger. You will see they have an LCD screen so you can see what's going on etc.

Above all, be careful.
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Old Mar 08, 2011, 05:43 AM
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overedline's Avatar
Chino Hills, CA
Joined Dec 2006
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Quote:
Originally Posted by lipoflyer View Post
NO!

You need to use a charger where you can get a read out of the voltage and miliamps being delivered to the pack. Don't cut corners here as the results will not be pretty. Do ant charging outside away from combustable items just incase. As an example of what I mean, go to hobbyking.com and search for an accucel 6 charger. You will see they have an LCD screen so you can see what's going on etc.

Above all, be careful.
Ok thanks. I will probably just buy a new lipo.
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Old May 30, 2011, 03:40 PM
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United States, CA, Oceanside
Joined Aug 2010
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I have a 2s 3300mah 7.4 battery bought new. I installed a deans plug, got the connections right, plugged it into a accucel 6 charger and all it will give me is a low cell voltage message. Can't get it to take a charge.

Any ideas on how to get it back, or is it dead.
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Old May 30, 2011, 07:15 PM
Space Coast USA
hoppy's Avatar
Space Coast
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Quote:
Originally Posted by Bill0 View Post
I have a 2s 3300mah 7.4 battery bought new. I installed a deans plug, got the connections right, plugged it into a accucel 6 charger and all it will give me is a low cell voltage message. Can't get it to take a charge.

Any ideas on how to get it back, or is it dead.
Read this Sticky


First rule of Lipo's - After receipt of a pack and before doing anything with the pack, check the individual cell voltages. If they aren't 3.85+/-, contact the vendor as something is wrong with the pack.
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Old Aug 06, 2011, 09:03 PM
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1500mah or 3000mah

hello im new to this stuff and clearly a rookie
my question is ...if i have a system running off a 3cell li-lion 1500mah
can i use a 3 cell 3000mah lipo without burning it up
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Old Aug 06, 2011, 09:46 PM
Space Coast USA
hoppy's Avatar
Space Coast
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Most likely, yes.
Tell me how much current you are drawing or how long your plane flies on a charge.
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Old Aug 06, 2011, 10:16 PM
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well its a helicopter running on 3s 1500mah li-lion
i dont know how much currant as i have no tester for that as of yet
and it flies for about 10-12mins i just dont want to burn out the esc as i dont know how big it is
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Old Aug 07, 2011, 06:23 AM
Space Coast USA
hoppy's Avatar
Space Coast
Joined Oct 2000
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If it flies for that long you should be OK with a larger pack.
Will the heli handle the extra weight?

You don't have to worry about the ESC, the amp draw in most cases will not change to any major degree by going to a larger pack. If it was a non-flying machine you could go to a 15000mah pack with out a problem.
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Old Mar 15, 2012, 05:55 PM
Senior to who? Member
crossup's Avatar
Annapolis, Maryland USA
Joined Feb 2001
2,450 Posts
for those who dont have a NiCad or other appropriate means to 'jump charge' a Lipo up to 3v per cell, one can use wall wart chargers IF the ratings are appropriate. For example, I have a Futaba 12FG which uses a 7.2v pack. The charger delivers approx. 9.5 v peak with a rating of 8.45v @170 ma. Perfect for 3 cell packs from 300mah up. A few jumper wires and you're in business....also it seems the sooner you take care of over discharged batteries, the better the result, so dont wait.
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Old Apr 02, 2012, 11:40 AM
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United States, FL, Ocala
Joined Sep 2011
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I have a 3s 2500mah lipo i use for my tx so it does't have the big deans size connector and I left my tx on and it wont even register on my lipo voltage checker..

plz help me recover it
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Old Apr 02, 2012, 02:54 PM
Southern Pride
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Haralson County GA. USA
Joined Oct 2004
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Please be advised that is why there is this Sticky Thread which stays near the top of this Forum.

"My battery is dead - HELP" info.

http://www.rcgroups.com/forums/showthread.php?t=1074181

Charles
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Old Apr 09, 2012, 02:07 PM
Whoops was it always in 2 bits
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United Kingdom, England, Rotherham
Joined Oct 2008
1,243 Posts
I tried this on what appeared to be a totally dead cell and it seemed to work in the fact that I managed to get it to start charging as a LiPo (single cell down the balance lead) and take it all the way to 4.2 volts putting in 4260mAh into the 5000mAh cell over the next 4 hours. However, almost instantly as the charging stopped it fell back to 3.6 volts.

Is it worth cycling this cell back down to 3.3 volts or am I flogging a dead horse?

Cheers
Kev
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Old Apr 09, 2012, 02:14 PM
Frankenstein recycled packs
rampman's Avatar
USA, AZ, Gilbert
Joined Jan 2006
8,684 Posts
THAT horse is one that can catch fire. HUGE internal short. Discharge 100%, solder discharge leads together and toss in garbage.

Rick
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