{"id":1708,"date":"2011-11-24T20:16:36","date_gmt":"2011-11-24T20:16:36","guid":{"rendered":"http:\/\/www.joswassink.nl\/insight\/?p=1708"},"modified":"2011-11-24T20:16:36","modified_gmt":"2011-11-24T20:16:36","slug":"urgenda-prize-for-battery-model","status":"publish","type":"post","link":"https:\/\/www.joswassink.nl\/insight\/?p=1708","title":{"rendered":"Urgenda prize for battery model"},"content":{"rendered":"<div id=\"attachment_1709\" style=\"width: 310px\" class=\"wp-caption alignleft\"><a rel=\"attachment wp-att-1709\" href=\"http:\/\/www.joswassink.nl\/insight\/?attachment_id=1709\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-1709\" class=\"size-thumbnail wp-image-1709\" title=\"LongLLam\" src=\"http:\/\/www.joswassink.nl\/insight\/wp-content\/uploads\/2011\/11\/LongLLam-300x199.jpg\" alt=\"\" width=\"300\" height=\"199\" \/><\/a><p id=\"caption-attachment-1709\" class=\"wp-caption-text\">Long Lam - Photo: Tomas van Dijk<\/p><\/div>\n<p><strong>Batteries represent half of the value of electric cars. Yet, until  recently, no one could clearly assess a battery\u2019s state of health.<\/strong><\/p>\n<p>Long Lam (MSc) won the best thesis prize for e-mobility, awarded by  Urgenda, a sustainability organisation, on 11 November &#8211; Sustainability  Day. Jury president Auke Hoekstra (MSc) appreciates the clarity that Lam  brought to the condition of batteries, and hopes that Lam\u2019s battery  model will now remove much of the uncertainty that is presently holding  lease companies back from including electric vehicles in their fleets.<!--more--><br \/>\n\u201cIn  his Master\u2019s thesis, Lam created a simple battery model that we can use  for electro-technical modelling of electric vehicles,\u201d says his  supervisor, Dr Pavol Bauer (EEMCS). \u201cIt\u2019s unique. No one had done that  before.\u201d<br \/>\nThe model describes a battery\u2019s state of health, its  voltage, capacity and resistance, as a function of its history. Lam  tested his model against an actual Li-ion battery in interrupted  charging and discharging sessions lasting more than one hour. The two  lines &#8211; theory and practice &#8211; coincided beautifully. The maximum  deviation was only 14 millivolts.<\/p>\n<p>\u201cThere are chemical battery models, electro-technical and  mathematical,\u201d says Lam, who extracted the knowledge from the chemical  models and translated it into an electro-technical model. He had to  simplify processes to obtain a formula that could be handled and also  had to contend with non-linear behaviour.<br \/>\n\u201cThere are a lot of fables  about batteries,\u201d Bauer adds. \u201cPeople say you have to charge and  discharge batteries to the maximum. We have shown that this is not  true.\u201d This used to be true for Nickel-cadmium batteries, but the wisdom  has lingered. Li-ion batteries in fact thrive best when used between 30  and 60 percent of their maximum charge.<\/p>\n<p>Charging frequently, and in small doses, is best for the batteries.  Coincidence or not, it\u2019s also what contactless power transfer (CPT), as  developed by Lam\u2019s former fellow student Swagat Chopra (MSc), offers.  Chopra\u2019s thesis was also nominated for the e-mobility thesis prize. The  jury apparently appreciates Bauer\u2019s Delft e-mobility programme.<br \/>\nAs  part of his prize, Lam will be allowed to drive an electric Tesla sports  car for a weekend. He says he\u2019ll wait until spring to make the most of  it: accelerating, speeding and driving down the batteries. Why are fun  things always detrimental?<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Batteries represent half of the value of electric cars. Yet, until recently, no one could clearly assess a battery\u2019s state of health.<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[59,149,264,265,329],"class_list":["post-1708","post","type-post","status-publish","format-standard","hentry","category-uncategorized","tag-batteries","tag-electric-vehicles","tag-lithium-ion-battery","tag-long-lam","tag-pavol-bauer"],"_links":{"self":[{"href":"https:\/\/www.joswassink.nl\/insight\/index.php?rest_route=\/wp\/v2\/posts\/1708","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.joswassink.nl\/insight\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.joswassink.nl\/insight\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.joswassink.nl\/insight\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.joswassink.nl\/insight\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1708"}],"version-history":[{"count":0,"href":"https:\/\/www.joswassink.nl\/insight\/index.php?rest_route=\/wp\/v2\/posts\/1708\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.joswassink.nl\/insight\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1708"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.joswassink.nl\/insight\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1708"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.joswassink.nl\/insight\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1708"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}