Pb Charging  
View related threads: (in this forum | in all forums)

Tower Hobbies
Enter up to 4 keywords or Tower stock numbers
Logged in as Guest



Users viewing this topic: none
  Printable Version
       

All Forums >> Radios, Batteries, Clubhouse and more >> Batteries & Chargers >> Pb Charging
Page: [1]

Login
Message << Older Topic   Newer Topic >>
Pb Charging - 12/26/2001 7:43:38 AM   
Edgar Perez



Posts: 1100
Joined: 12/1/2001
From: San Lorenzo, PUERTO RICO (USA)
Status: offline 		I need to charge my starter battery (1.2ah, 12Volt) and my flight box battery (9ah, 12 Volt). I have a supernova, but I’m unsatisfied with the rate the charger selects. As an example, after 6-7 hours it has only put 390 mah on my starter battery (the battery I believe was almost exhausted)


I have on loan a programmable power supply. I can select volts and amps into it. What should be the setting that will fully charge the Pb batteries without damage?

Thanks,
Edgar

PD: Is there anyway to coax the Supernova to do the recharging faster? Changing the rate manually don't help, since the system seems to select the rate automatically. I was providing 13.8Volts to the supernova.
       Post #: 1

charging 12V batteries - 12/27/2001 1:26:24 PM   
Miniair



Posts: 155
Joined: 11/29/2001
From: Medicine Hat, Alberta
Status: offline 		Are these sealed batteries or can you add water?

If they are sealed about the most you can put into them is 500MA or they will over charge and in most cases the case will bulge form the fumes created and not being able to escape will bulge the case. Also thay have been know to explode - not a very pretty site even if you weren't around at the time - Geled, hot acid all over the place.

Under no circumstances use an automotive type charger to charge sealed batteries.


_____________________________

Jim Rea
jr@miniair.com

(in reply to Edgar Perez)
       Post #: 2

Force feeding Pb battery - 12/27/2001 5:41:50 PM   
Red Scholefield



Posts: 4902
Joined: 12/8/2001
From: Newberry, FL, USA
Status: offline 		You might try charging it with by setting the SuperNova for Ni-Cd with C=100 ma for the 1.2 Mah cell and for C= 900 ma for the 9 Ah one in your field box. Do not let it go for more than 10 or 12 hours at these settings. Also watch the voltage. It should not go above 14.7 volts. If it does it indicates that the battery may be going bad (sulfated a bit) and should be replaced.

_____________________________

Red S.
AMA 951 Leader Member

(in reply to Edgar Perez)
       Post #: 3

both - 12/27/2001 7:00:29 PM   
Edgar Perez



Posts: 1100
Joined: 12/1/2001
From: San Lorenzo, PUERTO RICO (USA)
Status: offline 		Thanks to Red and Miniair ,

The starter is sealed, the flight box one is the type you can add water.

I understand about the sealed one cracking, but if the capacity is 1.2ah, why can't I only put 500mah?

Red, thanks for the settings. I will try them.

Edgar

(in reply to Edgar Perez)
       Post #: 4

pb batteries - 12/27/2001 8:18:55 PM   
Rodney



Posts: 4717
Joined: 12/8/2001
From: FL
Status: offline 		You should always use a constant voltage source to charge lead-acid batteries. If you have one you can accuratelly set, set it for 13.7 volts and you can leave it on for a very long time with no damage. If you set it at 14.7 volts, only leave it on charge long enough to bring the battery to full charge. When you use a constant voltage charge, the current will be high initially and taper off to near zero as the battery approaches full charge.

(in reply to Edgar Perez)
       Post #: 5

Pb Charging - 12/27/2001 11:07:29 PM   
Red Scholefield



Posts: 4902
Joined: 12/8/2001
From: Newberry, FL, USA
Status: offline 		Constant potential is the preffered way to charge lead acid batteries. Unfortunately in the real world these chargers are not always readily available and many sold for use with sealed lead acid batteries are a compromise and end up being neither constant voltage or constant current but somewhere in between. In a good constant voltage charger there is usually some provision for temperature compensation. This is required because the voltage is temperature dependent. This starts to add cost to the charger.

In our application, R/C starter and field box batteries we can work around the problem by using constant current chargers and limit the charge to something between C/10 and C/20. Watch the charge voltage and when it reaches 14.7 turn off the charger. This is for gel cells, flooded cells (motor cycle batteries to which you can add water) use a lower setting, something around 13.8. When you see bubbling its time to stop the charge. Start low and work up on the charge voltage cut off if you want to use a constant current. Working with these you will soon learn what your battery will tolerate.

If you see abnormally high voltage at the beginning of charge this indicates that the battery has become sulfated. Just leave the charger on and see if the voltage will come down. Sometimes you can bring on back in this manner if your charge source has high enough voltage to push a C/12 to C/20 charge rate.

_____________________________

Red S.
AMA 951 Leader Member

(in reply to Edgar Perez)
       Post #: 6

PB charging - 12/28/2001 4:23:49 AM   
Hobbsy



Posts: 10513
Joined: 12/2/2001
From: Colonial Beach, VA, USA
Status: offline 		I use an ACE CVC charger on both types and it does well.

_____________________________

"I have gone faster backwards, upside down and on fire than most people have gone at all" Don Garlits

(in reply to Edgar Perez)
       Post #: 7

pb charging - 12/28/2001 5:53:11 PM   
dant-RCU


 

Posts: 643
Joined: 12/7/2001
From: Tulsa, OK, USA
Status: offline 		There is an article on just this subject in the current issue of IMAA's High Flight Magazine. If you can find a copy, check out the article.

BTW, the author recommends just what hobbsy uses - the ACE CVC charger.

DAn


_____________________________

Dan Taylor
American Turf Flyers, Inc.

(in reply to Edgar Perez)
       Post #: 8

Page:   [1]
All Forums >> Radios, Batteries, Clubhouse and more >> Batteries & Chargers >> Pb Charging
Page: [1]





Jump to:


Google 



Search | Marketplace | Event Calendar | Local Clubs | Magazine | Product Ratings | New Products | Discussion Forums

Photo Gallery | Member Video Posts | RCU Video Gallery | Instructor Search | Field|Track|Marina Search

Advertisers | Hobby Vendor Resources | Rate Manufacturers | Sign In/Sign Up

SITE MAP!   : :   FORUM RULES

© 2001 - 2007 24-7 RC, LLC, all rights reserved.

Charities we support that also need your help
Yorkie Rescue | Humane Society | ASPCA | Crohn's-Colitis America

Kaango.com Classifieds

0.547RCU1