{"id":4423,"date":"2017-07-09T18:00:39","date_gmt":"2017-07-09T17:00:39","guid":{"rendered":"http:\/\/www.marshflattsfarm.org.uk\/wordpress\/?p=4423"},"modified":"2017-07-09T21:08:41","modified_gmt":"2017-07-09T20:08:41","slug":"electric-vehicle-charging","status":"publish","type":"post","link":"https:\/\/www.marshflattsfarm.org.uk\/wordpress\/?p=4423","title":{"rendered":"Electric Vehicle Charging"},"content":{"rendered":"<p>I predict an electric car in my future &#8211; I had a brief test drive in a BMW i3 the other day and was very impressed. Got a longer test drive scheduled in a couple of weeks and I&#8217;ll see how the numbers stack up after that.<\/p>\n<p>Electric car = electric car charging which warrants some research. While it&#8217;s perfectly possible to connect a low-current charger (as supplied with the car) to one of the external 13A sockets and leave it at that there are some other \/ better options to consider:<\/p>\n<ul>\n<li>A dedicated EVSE (Electric Vehicle Supply Equipment) &#8220;charger&#8221;\n<ul>\n<li>The actual &#8220;battery charger&#8221; is part of the car and the various alternative solutions are just different ways of supplying electricity to the car so it can decide how to proceed<\/li>\n<\/ul>\n<\/li>\n<li>Some means of dynamically scheduling the charging, to either take advantage of a cheaper electricity tariff or spare solar generation capacity<\/li>\n<\/ul>\n<p>Initially I found the terminology around the many options for EV charging quite confusing (Type versus Level versus Mode etc.) but I think I&#8217;ve fought my way through that now:<\/p>\n<ul>\n<li><strong>Type<\/strong> refers to the style of socket on the car\n<ul>\n<li>The BMW i3 models made for the European market are fitted with an\u00a0IEC 62196\u00a0&#8220;Type 2&#8221; (aka\u00a0Mennekes) socket<\/li>\n<\/ul>\n<\/li>\n<li><strong>Level<\/strong> refers to the nature of the electricity supply\n<ul>\n<li>Level 1 is 120V AC (mostly of relevance in the Americas)<\/li>\n<li>Level 2 is 240V AV (standard in Europe)<\/li>\n<li>Level 3 is 480V DC (not relevant for domestic charging)<\/li>\n<\/ul>\n<\/li>\n<li><strong>Mode<\/strong> refers to the nature of the communications between the car and the EVSE &#8211; basically:\n<ul>\n<li>The simple EVSEs typically supplied with EVs and fitted with a standard 13A plug are Mode 2 and operate at a maximum of 10A<\/li>\n<li>The hard-wired EVSEs are Mode 3 and communicate with the car using a protocol defined as part of the <a href=\"https:\/\/en.wikipedia.org\/wiki\/SAE_J1772\" target=\"_blank\" rel=\"noopener\">SAE J1772<\/a> standard\n<ul>\n<li>The most interesting part of this is that the car decides what current to draw but it does that based on information advertised by the EVSE<\/li>\n<li>Mostly this is used to protect the weakest part of the electrical circuit from overload (typically it&#8217;s the cable) but it can also be used to &#8220;ask&#8221; the car to charge at a lower rate than it might otherwise try to achieve<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<p>There are various commercial options for EVSEs &#8211; e.g. BMW offer a Wallbox (in BMW colours) &#8211; but I&#8217;m currently favouring the Open Source <a href=\"https:\/\/www.openevse.com\" target=\"_blank\" rel=\"noopener\">OpenEV<\/a> which is available from the <a href=\"https:\/\/shop.openenergymonitor.com\/openevse-wifi-emoncms-ev-charging-station-kit\/\" target=\"_blank\" rel=\"noopener\">OpenEnergyMonitor<\/a> folks (and integrates with their other solutions &#8211; or other Open Source solutions).<\/p>\n<p>To be able to charge at 7.4 kW (32A @ 230V AC) requires a dedicated circuit with some fairly chunky wiring direct from the main consumer unit (or in my case from a new consumer unit since the <em>two<\/em> primary consumer units are already &#8220;full&#8221;). Fortunately I predicted the need for some sort of external connection and there&#8217;s already some ducting installed to take it. It will also warrant an extra sub-meter to monitor how much electricity is being used to charge the car.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>I predict an electric car in my future &#8211; I had a brief test drive in a BMW i3 the other day and was very impressed. Got a longer test drive scheduled in a couple of weeks and I&#8217;ll see &hellip; <a href=\"https:\/\/www.marshflattsfarm.org.uk\/wordpress\/?p=4423\">Continue reading <span class=\"meta-nav\">&rarr;<\/span><\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[29],"tags":[],"class_list":["post-4423","post","type-post","status-publish","format-standard","hentry","category-electricity"],"_links":{"self":[{"href":"https:\/\/www.marshflattsfarm.org.uk\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/4423","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.marshflattsfarm.org.uk\/wordpress\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.marshflattsfarm.org.uk\/wordpress\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.marshflattsfarm.org.uk\/wordpress\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.marshflattsfarm.org.uk\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=4423"}],"version-history":[{"count":1,"href":"https:\/\/www.marshflattsfarm.org.uk\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/4423\/revisions"}],"predecessor-version":[{"id":4424,"href":"https:\/\/www.marshflattsfarm.org.uk\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/4423\/revisions\/4424"}],"wp:attachment":[{"href":"https:\/\/www.marshflattsfarm.org.uk\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=4423"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.marshflattsfarm.org.uk\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=4423"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.marshflattsfarm.org.uk\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=4423"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}