{"id":14657,"date":"2017-01-01T19:45:58","date_gmt":"2017-01-02T00:45:58","guid":{"rendered":"http:\/\/www.tasteyourjuice.com\/wordpress\/?p=14657"},"modified":"2017-01-01T19:45:58","modified_gmt":"2017-01-02T00:45:58","slug":"a-battery-mooch-post-a-lipo-ratings-rant","status":"publish","type":"post","link":"https:\/\/www.tasteyourjuice.com\/wordpress\/archives\/14657","title":{"rendered":"A BATTERY MOOCH POST: A LiPo ratings rant"},"content":{"rendered":"<p>What the hell is going on? How did it get like this?<br \/>\nAs I work through finalizing the list of tests to perform on these LiPo battery packs, and how to best present the data, one thing has become very clear&#8230;.most LiPo &#8220;C&#8221; ratings are complete fantasy.<\/p>\n<p>Not just exaggerated but beyond comprehension as to how they could be set this high. They are obviously &#8220;pulse&#8221; ratings of some kind but even then they&#8217;re preposterous.<\/p>\n<p>For example&#8230;<br \/>\nA very respected company has rated a pack in the 1800mAh range at 100C. That&#8217;s a rating of 180A. It has a DC internal resistance averaging of 42mOhms after break-in, very high. At 180A that means even when only pulsed, with a freshly charged 3S pack, the voltage drops from 12.6V to just over 5.0V instantly.<\/p>\n<p>The minimum voltage is 9.0V for the pack. That 100C rating is utterly and completely useless and instantly brings each cell down to a level that can quickly damage it.<\/p>\n<p>Another example of ratings silliness&#8230;<br \/>\nMore than one of these 1800mAh packs has a C rating that results in a current rating above 117A. Why is that important? Because at 117A for more than a few seconds the 16AWG wire some packs use can melt&#8230;literally! Even if the current is pulsed the wires can reach VERY high temperatures, hundreds of degrees, at that current level. How can that possibly have been thought to be a rating, of any kind?<\/p>\n<p>Another example&#8230;<br \/>\nThe ThunderPower Rampage 70C pack (not in the table) has a continuous current rating of 126A, as listed on the Thunderpower web site. Even the 12AWG wire it uses will reach hundreds of degrees when used at that high a continuous current level and very high temperatures when pulsed. The voltage sag will be huge too. Just ridiculous.<\/p>\n<p>Having said all this, the worst 1800mAh pack still outperforms the best pack we can make from 18650&#8217;s. I just want to inject a bit of sanity into the process of choosing a LiPo.<\/p>\n<p>The table I&#8217;ve attached here shows the internal resistances of the 1800mAh packs I am testing. The names will be hidden until testing is done. You can see that two packs have very high internal resistance, a couple are fairly low, and the rest are in between. Interestingly, the lowest resistances do not belong to the packs with the best reputations. Quite the contrary in fact.<\/p>\n<p>More info to come as the testing continues.<\/p>\n<p>https:\/\/imgur.com\/a\/M6uZq<\/p>\n<div style=\"padding-bottom:20px; padding-top:10px;\" class=\"hupso-share-buttons\"><!-- Hupso Share Buttons - https:\/\/www.hupso.com\/share\/ --><a class=\"hupso_toolbar\" href=\"https:\/\/www.hupso.com\/share\/\"><img decoding=\"async\" src=\"https:\/\/static.hupso.com\/share\/buttons\/dot.png\" style=\"border:0px; padding-top: 5px; float:left;\" alt=\"Share Button\"\/><\/a><script type=\"text\/javascript\">var hupso_services_t=new Array(\"Twitter\",\"Facebook\",\"Google Plus\",\"Pinterest\",\"Reddit\");var hupso_background_t=\"#EAF4FF\";var hupso_border_t=\"#66CCFF\";var hupso_toolbar_size_t=\"medium\";var hupso_image_folder_url = \"\";var hupso_url_t=\"\";var hupso_title_t=\"A%20BATTERY%20MOOCH%20POST%3A%20A%20LiPo%20ratings%20rant\";<\/script><script type=\"text\/javascript\" src=\"https:\/\/static.hupso.com\/share\/js\/share_toolbar.js\"><\/script><!-- Hupso Share Buttons --><\/div>","protected":false},"excerpt":{"rendered":"<p>What the hell is going on? How did it get like this? As I work through finalizing the list of tests to perform on these&#8230;<\/p>\n","protected":false},"author":8,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[139,15],"tags":[],"class_list":["post-14657","post","type-post","status-publish","format-standard","hentry","category-the-battery-mooch","category-recent_news","wpcat-139-id","wpcat-15-id"],"_links":{"self":[{"href":"https:\/\/www.tasteyourjuice.com\/wordpress\/wp-json\/wp\/v2\/posts\/14657","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.tasteyourjuice.com\/wordpress\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.tasteyourjuice.com\/wordpress\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.tasteyourjuice.com\/wordpress\/wp-json\/wp\/v2\/users\/8"}],"replies":[{"embeddable":true,"href":"https:\/\/www.tasteyourjuice.com\/wordpress\/wp-json\/wp\/v2\/comments?post=14657"}],"version-history":[{"count":0,"href":"https:\/\/www.tasteyourjuice.com\/wordpress\/wp-json\/wp\/v2\/posts\/14657\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.tasteyourjuice.com\/wordpress\/wp-json\/wp\/v2\/media?parent=14657"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.tasteyourjuice.com\/wordpress\/wp-json\/wp\/v2\/categories?post=14657"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.tasteyourjuice.com\/wordpress\/wp-json\/wp\/v2\/tags?post=14657"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}