<div dir="ltr">IT's actually I^2*R, not just I*R, but since the resistance is the linear term here, you are basically looking at 2x the heat from Brand B vs. Brand A. The heat has to come from somewhere, and in this case that's battery power that could have turned your prop and is instead going to self-destruction via heat.<div>
<br></div><div>Peter+</div></div><div class="gmail_extra"><br><br><div class="gmail_quote">On Fri, Jul 26, 2013 at 1:03 PM, Bob Kane <span dir="ltr"><<a href="mailto:getterflash@yahoo.com" target="_blank">getterflash@yahoo.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div><div style="font-size:12pt;font-family:times new roman,new york,times,serif"><div><span style="background-color:transparent;font-size:12pt">Without doing much math, from your note below Brand B is roughly twice the resistance of Brand A, so it will run hotter if run at the same current.</span><br>
</div><div style="font-style:normal;font-size:16px;background-color:transparent;font-family:'times new roman','new york',times,serif"><br></div><div style="font-style:normal;font-size:16px;background-color:transparent;font-family:'times new roman','new york',times,serif">
If you want to do the math, t<span style="font-size:12pt">he simple way is to measure the current at full throttle, then plug the number into this equation:</span></div><div style="font-style:normal;font-size:12pt;background-color:transparent;font-family:'times new roman','new york',times,serif">
<span style="background-color:transparent;font-size:12pt">Power = MaxCurrent * 1000 * Cell Resistance (in Milliohms) This will tell you how much power is being absorbed by the packs. More power absorbed is bad, less power absorbed is good.</span></div>
<div style="font-style:normal;font-size:12pt;background-color:transparent;font-family:'times new roman','new york',times,serif"><span style="font-size:12pt"><br></span></div><div style="font-style:normal;font-size:16px;background-color:transparent;font-family:'times new roman','new york',times,serif">
<span style="font-size:12pt">Converting power absorbed into temperature rise over time is more complicated.</span></div><div style="font-style:normal;font-size:16px;background-color:transparent;font-family:'times new roman','new york',times,serif">
<span style="font-size:12pt"> </span><br></div><div>Bob Kane<br><a href="mailto:getterflash@yahoo.com" target="_blank">getterflash@yahoo.com</a></div><div><br></div> <div style="font-family:'times new roman','new york',times,serif;font-size:12pt">
<div style="font-family:'times new roman','new york',times,serif;font-size:12pt"> <div dir="ltr"> <hr size="1"> <font face="Arial"> <b><span style="font-weight:bold">From:</span></b> J N Hiller <<a href="mailto:jnhiller@earthlink.net" target="_blank">jnhiller@earthlink.net</a>><br>
<b><span style="font-weight:bold">To:</span></b> NSRCA Mailing List <<a href="mailto:nsrca-discussion@lists.nsrca.org" target="_blank">nsrca-discussion@lists.nsrca.org</a>> <br> <b><span style="font-weight:bold">Sent:</span></b> Friday, July 26, 2013 3:30 PM<br>
<b><span style="font-weight:bold">Subject:</span></b> [NSRCA-discussion] LIPO Question<br> </font> </div><div><div class="h5"> <div><br>HELP!<br><br>I'm trying to understand battery heat gained from internal cell resistance.<br>
Total resistance of brand A = 13, Brand B = 28 (Twin 5S 5000 packs -
new -<br>unused).<br><br>Can someone point me to a formula?<br><br>Thanks<br>Jim Hiller<br><br>_______________________________________________<br>NSRCA-discussion mailing list<br><a href="mailto:NSRCA-discussion@lists.nsrca.org" target="_blank">NSRCA-discussion@lists.nsrca.org</a><br>
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