{"id":1209,"date":"2013-11-27T13:58:02","date_gmt":"2013-11-27T13:58:02","guid":{"rendered":"https:\/\/ibex.tech\/resources\/?p=1209"},"modified":"2022-02-18T15:05:17","modified_gmt":"2022-02-18T15:05:17","slug":"nimh-batteries","status":"publish","type":"post","link":"https:\/\/ibex.tech\/resources\/geek-area\/electronics\/batteries\/nimh-batteries","title":{"rendered":"NiMh Batteries"},"content":{"rendered":"<h4>\nNiMh Cell Voltage<br \/>\n<\/h4>\n<p>\n0.9 to 1.5V (cell voltage typically specified as 1.2V nominal)\n<\/p>\n<h4>\n<strong>General Notes<\/strong><br \/>\n<\/h4>\n<p>\nHigh self-discharge rate of over 30% per month in common nickel metal hydride batteries\n<\/p>\n<p>\nThere tends to be 2 grades of battery:- consumer where capacity may be higher but number of discharge cycles will be lower (big numbers are best), and industrial where capacity will be a bit less but discharge cycles of say 500 are common specs.\n<\/p>\n<h5>\n<strong>What kind of protections are needed for Ni-MH batteries, respectively?<\/strong><br \/>\n<\/h5>\n<p>\nIn addition to the self-protections of the battery cells, a well designed charger and protection circuitry are also very important. For the protection circuitry, Ni-MH is much easier than&nbsp;li-ion. Often chargers include a&nbsp;polyswitch&nbsp;connected in series with the batteries and a&nbsp;thermoresistor&nbsp;with one-end connected to the ground power line and the other end to charger control. When short circuit happens, the&nbsp;polyswitch&nbsp;will be heated up and the resistance will increase rapidly to stop the current. When the temperature cools down, it will resume the supply of the power. The&nbsp;thermoresistor&nbsp;is used by the charger. When the charger find that the battery temperature increases (through the increase of the&nbsp;thermoresistor&#39;s&nbsp;resistance), it will shut down the charging process. These two parts cost very little and are much cheaper than the&nbsp;li-ion&nbsp;protection circuit board.\n<\/p>\n<h5>\n<strong>What&#39;s the maximum instantaneous discharge current of Ni-MH battery cells?<\/strong><br \/>\n<\/h5>\n<p>\nTypically the Ni-MH battery cell can be discharged at&nbsp;5C~10C&nbsp;condition for several seconds. For example, an&nbsp;ED2000mA&nbsp;battery cell (capacity:&nbsp;2Ah) can output&nbsp;10A~20A&nbsp;current (2Ax5&nbsp;~&nbsp;2Ax10) if the discharge does not last for too long. This makes Ni-MH good for many high current applications, such as power hand tools and UPS.\n<\/p>\n<h5>\n<strong>What&#39;s the maximum fast discharge current of Ni-MH battery cells?<\/strong><br \/>\n<\/h5>\n<p>\nTypically the Ni-MH battery can be discharged at&nbsp;3C~5C&nbsp;condition for 12~20 minutes. For example, an&nbsp;ED1600AA&nbsp;battery cell (capacity: 1.6Ah) can continuously output 4.8A~8A&nbsp;current (1.6Ax3 ~ 1.6Ax5) for 12~20 minutes\n<\/p>\n<p>\n&nbsp;\n<\/p>\n<p>\n&nbsp;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>NiMh Cell Voltage 0.9 to 1.5V (cell voltage typically specified as 1.2V nominal) General Notes High self-discharge rate of over 30% per month in common nickel metal hydride batteries There tends to be 2 grades of battery:- consumer where capacity may be higher but number of discharge cycles will be lower (big numbers are best), [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[29],"tags":[],"class_list":["post-1209","post","type-post","status-publish","format-standard","hentry","category-batteries"],"_links":{"self":[{"href":"https:\/\/ibex.tech\/resources\/wp-json\/wp\/v2\/posts\/1209","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/ibex.tech\/resources\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/ibex.tech\/resources\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/ibex.tech\/resources\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/ibex.tech\/resources\/wp-json\/wp\/v2\/comments?post=1209"}],"version-history":[{"count":3,"href":"https:\/\/ibex.tech\/resources\/wp-json\/wp\/v2\/posts\/1209\/revisions"}],"predecessor-version":[{"id":1822,"href":"https:\/\/ibex.tech\/resources\/wp-json\/wp\/v2\/posts\/1209\/revisions\/1822"}],"wp:attachment":[{"href":"https:\/\/ibex.tech\/resources\/wp-json\/wp\/v2\/media?parent=1209"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/ibex.tech\/resources\/wp-json\/wp\/v2\/categories?post=1209"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/ibex.tech\/resources\/wp-json\/wp\/v2\/tags?post=1209"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}