A DIY A123 receiver battery-pack

If you've been building electronic bits or modifying stuff you've bought then tell us all about it here. A good place to discuss the installation of 2.4GHz DIY modules too.

A DIY A123 receiver battery-pack

Postby RCModelReviews » Fri Dec 31, 2010 8:28 pm

Project video is at: http://www.youtube.com/watch?v=BN9_3nMTvc0

Please feel free to place your comments and questions in this thread and I'll be happy to answer or elaborate for you.
RCModelReviews.com, just the facts.
User avatar
RCModelReviews
 
Posts: 2120
Joined: Tue May 04, 2010 3:40 am

Re: A DIY A123 receiver battery-pack

Postby Startazz » Fri Dec 31, 2010 9:54 pm

I've just seen the video Bruce and thought it was good but what i wanted to know is could we knock some of these batteries up for our main flight batteries?? like say a 1800mah 11.1v or am i way off the mark?? i only ask because i'm still learning about all these different batteries as you might be able to tell ;)
IT'S BETTER TO DIE A TIGER THAN TO DIE AS A PUSSY!
Startazz
 
Posts: 18
Joined: Thu May 13, 2010 3:06 pm

Re: A DIY A123 receiver battery-pack

Postby radialarm » Wed Jan 05, 2011 6:20 am

I was watching your video, and noticed the voltage of the pack. All my Rx's state max. 6V, and two of these cells are 7.4V. Am I correct? I could be wrong as I'm not too knowledgeable about the A123 cells. My question is, is it safe to use this voltage with my Rx's. I know that under load the voltage will be lower.
radialarm
 
Posts: 1
Joined: Sat Oct 09, 2010 12:43 am

Re: A DIY A123 receiver battery-pack

Postby TG72 » Wed Jan 05, 2011 2:10 pm

IMO, your best how to (101) video to date. These are excellent Bruce, and hope there are many more to come. Thanks!
TG72
 
Posts: 33
Joined: Mon Sep 27, 2010 4:16 am
Location: Linn,Tx.

Re: A DIY A123 receiver battery-pack

Postby SansHeli » Sun Jan 23, 2011 1:56 am

radialarm wrote:I was watching your video, and noticed the voltage of the pack. All my Rx's state max. 6V, and two of these cells are 7.4V. Am I correct? I could be wrong as I'm not too knowledgeable about the A123 cells. My question is, is it safe to use this voltage with my Rx's. I know that under load the voltage will be lower.


I had the same concerns re. the voltage at full charge so I would like to hear if we are risking inducing some of the "magic smoke" (as Bruce so eloquently puts it).

BTW, Bruce, thanks for all your effort in putting the YouTube vids and web site articles together - much appreciate the "honesty and non-advertising biased" opinions. Keep up the good work!!
"It's not just that helicopters crash. They crash, then in many cases continue to beat themselves to death." - RH

Raptor 50 V2 & SE, T-REX 450 SE, (and a number of gas and elec. planes), JR12X, JR XP9303/Spektrum 2.4GHz
User avatar
SansHeli
 
Posts: 2
Joined: Fri Jan 21, 2011 7:58 pm
Location: Brisbane, Australia

Re: A DIY A123 receiver battery-pack

Postby RCModelReviews » Sun Jan 23, 2011 5:56 am

Two lithium-ion or lipo cells will deliver 7.2V but A123 cells use a different chemistry (LiFePO4) so they have a nominal voltage of 3.3V per cell (6.6V per 2-cell pack).

Experience has shown that, apart from some 9g and smaller servos, or a few used on helicopter tail-rotors, all other RC servos (rated for 6V) work just fine on the 6.6V that such a pack puts out. The same goes for the receivers. All receivers have a voltage regulator that drops the voltage down to (in the case of 2.4GHz stuff) 3.3V or less anyway.
RCModelReviews.com, just the facts.
User avatar
RCModelReviews
 
Posts: 2120
Joined: Tue May 04, 2010 3:40 am

Re: A DIY A123 receiver battery-pack

Postby lowglow » Mon Jan 24, 2011 7:44 am

All receivers have a voltage regulator that drops the voltage down to (in the case of 2.4GHz stuff) 3.3V or less anyway.


Bruce does this apply to the Assan recievers? I am sick of unreliable Nicad packs and I'm keen to give the A123 packs a go.
User avatar
lowglow
 
Posts: 2
Joined: Mon Jan 24, 2011 7:19 am
Location: Blenheim NZ

Re: A DIY A123 receiver battery-pack

Postby RCModelReviews » Tue Jan 25, 2011 3:17 am

Yes, this applies to Assan.
RCModelReviews.com, just the facts.
User avatar
RCModelReviews
 
Posts: 2120
Joined: Tue May 04, 2010 3:40 am

Re: A DIY A123 receiver battery-pack

Postby lowglow » Tue Jan 25, 2011 5:56 am

Great, guess I betta place an order with HK then :D
User avatar
lowglow
 
Posts: 2
Joined: Mon Jan 24, 2011 7:19 am
Location: Blenheim NZ

Re: A DIY A123 receiver battery-pack

Postby Kamu » Sun Jan 30, 2011 3:49 pm

While watching this you were so careful not to short the battery leads. But you didn't mention a warning when you were checking the receiver plug with the multimeter. It is so easy to cross those two while metering them!
Kamu
 
Posts: 34
Joined: Sat Jan 08, 2011 8:25 am

Next

Return to DIY Projects and Hacks

Who is online

Users browsing this forum: No registered users and 10 guests

cron