{"id":8627,"date":"2013-10-26T21:52:09","date_gmt":"2013-10-27T04:52:09","guid":{"rendered":"http:\/\/rustybolt.info\/wordpress\/?p=8627"},"modified":"2013-10-27T23:15:24","modified_gmt":"2013-10-28T06:15:24","slug":"2013-10-26-battery-capacity","status":"publish","type":"post","link":"https:\/\/rustybolt.info\/wordpress\/?p=8627","title":{"rendered":"2013-10-26 Spent Battery Capacity"},"content":{"rendered":"<p>I was reading <a href=\"http:\/\/www.edn.com\/design\/led\/4363679\/LED-flashlight-circuit-works-at-voltages-as-low-as-0-5V\"><strong>this article<\/strong><\/a> and saw that it said that when the voltage of a 1.5V cell drops to 0.9V, it still has 10 percent of its capacity left.\u00a0 I have read in the past that the battery is considered used up when its voltage drops to 1 volt.\u00a0 I don&#8217;t know what the percent difference is between 0.9V and 1 volt, but I presume that the capacity is somewhat more than ten percent.\u00a0 I would not expect it to be 20 percent, though.<\/p>\n<p>One point of this is that the amount of capacity left in the cell when it&#8217;s considered spent or dead is not very much.\u00a0 But the ten or whatever percent is there and it&#8217;s free, and can be used by the Joule Thief to make a LED light up,<\/p>\n<p>One point I would like to remind readers about is that the typical conventional Joule Thief is only putting out half of the power that it takes in (and that&#8217;s when the input voltage is 1.5V; when it&#8217;s only 0.9V, it&#8217;s likely even less than half).\u00a0 Therefore the ten percent left in the cell actually looks like only five percent when it&#8217;s lighting the LED.\u00a0 One could get better efficiency if 5 of the spent cells are put in series and the resulting 4.5V is used to run the LED with a current limiting resistor.\u00a0 The efficiency with the current limiting resistor could be 70 percent.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>I was reading this article and saw that it said that when the voltage of a 1.5V cell drops to 0.9V, it still has 10 percent of its capacity left.\u00a0 I have read in the past that the battery is considered used up when its voltage drops to 1 volt.\u00a0 I don&#8217;t know what the<a href=\"https:\/\/rustybolt.info\/wordpress\/?p=8627\"> <\/p>\n<p> (Read More&#8230;)<\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[141,4],"tags":[],"class_list":["post-8627","post","type-post","status-publish","format-standard","hentry","category-free-energy","category-joule-thief-smps-dc-dc"],"_links":{"self":[{"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/8627","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=8627"}],"version-history":[{"count":7,"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/8627\/revisions"}],"predecessor-version":[{"id":8666,"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/8627\/revisions\/8666"}],"wp:attachment":[{"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=8627"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=8627"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=8627"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}