977 ?'s  
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 >> MRC Charger Product Support (i.e. Super Brain, etc) >> 977 ?'s
Page: [1]

Login
Message << Older Topic   Newer Topic >>
977 ?'s - 7/16/2007 6:10:27 AM   
flyinmoose



Posts: 121
Joined: 8/4/2006
From: Huntsville, AL, USA
Status: offline 		I have the superbrain 977 and I charge 21003s11.1V batteries on it. What is the cutoff voltage per cell? I m only getting about 12.2 volts at the end of a charge at a rate of 2.0 amps. I ve also tried 2.1 and no difference. That result comes from the DC power supply(car battery). When I use the AC power supply with the charger I only get 11.5V per charge. Is this an issue of a bad power supply, if so what can I do about it? I balance my batts regularly. Thanks for your time.
Matt

_____________________________

You can get a good look at T-bone by sticking your head up a bulls a$$, but wouldn't you rather take the butchers word.
       Post #: 1

RE: 977 ?'s - 7/16/2007 4:32:06 PM   
Tim@MRC


 

Posts: 356
Joined: 7/24/2006
From: Edison, NJ, USA
Status: offline 		The 977 has a voltage cutoff of around 4.15 volts per cell. My engineer did this to be a little on the conservative side for LiPo's. You may actually get a better result from the 12 volt car battery rather than the power supply if the battery is fully charged (13.5 volts). The power supply is rated for 13.5 volts, but as it goes through the circuitry and wiring in the power supply, it actually comes out around 12.8 volts. Check the output voltage of the power supply with a volt meter and let me know what’s coming out.

Tim

(in reply to flyinmoose)
       Post #: 2

RE: 977 ?'s - 7/18/2007 5:47:41 AM   
flyinmoose



Posts: 121
Joined: 8/4/2006
From: Huntsville, AL, USA
Status: offline 		When I put the meter on the PS it said just under 13V so I guess that's not the problem. What is the cutoff per cell on the discharge side of things? Or should I not discharge my lipos? If so what kind of settings should I use?
Thanks
Matt

_____________________________

You can get a good look at T-bone by sticking your head up a bulls a$$, but wouldn't you rather take the butchers word.

(in reply to Tim@MRC)
       Post #: 3

RE: 977 ?'s - 7/18/2007 4:06:34 PM   
Tim@MRC


 

Posts: 356
Joined: 7/24/2006
From: Edison, NJ, USA
Status: offline 		You can discharge the LiPos, but don't go below 3 volts per cell. The 977 looks for a sharp drop in voltage for the cutoff on discharge. Batteries typically have a long voltage plateau, and then when they reach the point at which they're discharged there will be a sharp drop in voltage. This is what the 977 looks for. You should really be using a balancer on your LiPos. This equalizes the cells and prevents over charging or discharging. It's not necessary to balance on every charge/discharge, but I'd say every 12 - 20 charges. I've read differing opinions on this, but 12 - 20 charges seems to be the average.

(in reply to flyinmoose)
       Post #: 4

Page:   [1]
All Forums >> Radios, Batteries, Clubhouse and more >> Batteries & Chargers >> MRC Charger Product Support (i.e. Super Brain, etc) >> 977 ?'s
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

0.328RCU1