[NSRCA-discussion] Heat Sinks

[glmiller3 at suddenlink.net]

Fascinating stuff, Jeremy, Thanks for the reference.  It looks to me (as a naive evaluation) that the energy cost and additional heat generated would be more than the potential gain for our uses-- unless they were built into the battery packs- but then you'd have to somehow vent the "hot side" away from the adjacent cell....what we really need is better airflow over/around our cells---like hanging them out in the air like the Kudzu- or putting them in an open pipe tunnel like I did on my E Focus conversions.  All my batteries enclosed in a fuse get hotter than I'd like (125-135 F) though I've been told this is "optimum operating temp" anyway.  I've played with ductwork, vents and exhaust configurations and I can't honestly tell much difference.

G
---- JEREMY CHINN <lagrue at hotmail.com> wrote: 

=============

With much the same question in mind, I found this with Google.....
 
http://www.dansdata.com/peltprac.htm
 
> Date: Fri, 1 Aug 2008 09:24:56 -0500> From: glmiller3 at suddenlink.net> To: jpavlick at idseng.com; nsrca-discussion at lists.nsrca.org> Subject: Re: [NSRCA-discussion] Heat Sinks> > What the heck are Peltiers? Flying in LA I never have to worry about batteries being too COOL!> > I'm always looking for a way to improve heat exchange, though. > > G> ---- John Pavlick <jpavlick at idseng.com> wrote: > > =============> You didn't fly fast enough to heat them up! <LOL> Seriously, LiPOs perform best within a certain temperature range. You electron heads should look into something that can keep the batteries within this range. Maybe Peltiers? These are nice because thay can generate heat OR provide a cooling effect. If anyone wants to explore this I'd be glad to help.> > John Pavlick> > JEREMY CHINN <lagrue at hotmail.com> wrote:> .hmmessage P { margin:0px; padding:0px } body.hmmessage { FONT-SIZE: 10pt; FONT-FAMILY:Tahoma } The assessment on my Kudzu at the Nats was that my batteries never even got to optimum operating temperature...... > > > ---------------------------------> From: jpavlick at idseng.com> To: nsrca-discussion at lists.nsrca.org> Date: Thu, 31 Jul 2008 22:12:06 -0400> Subject: Re: [NSRCA-discussion] Heat Sinks> > Sounds heavy. Don't electric airplanes have trouble making weight (except for Dave Lockhart's of course)? What are you guys doing for letting air in / out of the fuse. Without proper airflow, even a good heat sink won't work. Actually wouldn't it be better to make some kind of (light weight) thermostatically controlled cooling system? Cold LiPOs don't make optimum power.> > John Pavlick> http://www.idseng.com> ----- Original Message ----- > From: Earl Haury > To: Discussion List, NSRCA > Sent: Thursday, July 31, 2008 9:49 PM> Subject: [NSRCA-discussion] Heat Sinks> > > We all tend to mount E batteries on some sort of wooden / carbon / nomex shelf and tie them down with Velcro or a clamp plate - none of which are very good at transferring heat. Possibly we could improve heat transfer from the batts to the cooling air by using aluminum, or better yet - finned aluminum heatsink material for the shelf / clamp. > > I've spent a fair bit of time trying for find appropriate heatsink material online - something 4" long x 3" wide with a high count of thin, maybe 1/4 high, fins might work. Unfortunately, there's tons of heatsink material available from Newark, Mauser, etc. but it's difficult to find the right stuff - especially material light enough for our use. The closest I've come is Thermaflo # E1243, but I'm lacking a small quantity source. > > Anybody work with this stuff & have recommendations or sources?> > Earl> > ---------------------------------> > _______________________________________________> NSRCA-discussion mailing list> NSRCA-discussion at lists.nsrca.org> http://lists.nsrca.org/mailman/listinfo/nsrca-discussion> > > ---------------------------------> Use video conversation to talk face-to-face with Windows Live Messenger. Get started. _______________________________________________> NSRCA-discussion mailing list> NSRCA-discussion at lists.nsrca.org> http://lists.nsrca.org/mailman/listinfo/nsrca-discussion> > _______________________________________________> NSRCA-discussion mailing list> NSRCA-discussion at lists.nsrca.org> http://lists.nsrca.org/mailman/listinfo/nsrca-discussion
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