{"id":24,"date":"2013-04-17T08:55:41","date_gmt":"2013-04-17T15:55:41","guid":{"rendered":"http:\/\/pididu.com\/wordpress\/solarbike\/?p=24"},"modified":"2013-05-09T20:59:45","modified_gmt":"2013-05-10T03:59:45","slug":"monitoring-battery-voltage","status":"publish","type":"post","link":"http:\/\/pididu.com\/wordpress\/solarbike\/monitoring-battery-voltage\/","title":{"rendered":"Monitoring Battery Voltage"},"content":{"rendered":"<figure id=\"attachment_25\" aria-describedby=\"caption-attachment-25\" style=\"width: 480px\" class=\"wp-caption aligncenter\"><a href=\"http:\/\/pididu.com\/wordpress\/solarbike\/files\/2013\/04\/VoltageMonitor.jpg\"><img decoding=\"async\" loading=\"lazy\" class=\"size-full wp-image-25\" alt=\"DVM monitoring electric bike battery voltage\" src=\"http:\/\/pididu.com\/wordpress\/solarbike\/files\/2013\/04\/VoltageMonitor.jpg\" width=\"480\" height=\"640\" srcset=\"http:\/\/pididu.com\/wordpress\/solarbike\/files\/2013\/04\/VoltageMonitor.jpg 480w, http:\/\/pididu.com\/wordpress\/solarbike\/files\/2013\/04\/VoltageMonitor-225x300.jpg 225w\" sizes=\"(max-width: 480px) 100vw, 480px\" \/><\/a><figcaption id=\"caption-attachment-25\" class=\"wp-caption-text\">A voltmeter is clipped to the charging port to monitor the battery voltage under various conditions.<\/figcaption><\/figure>\n<p>A battery charger generally needs to know the voltage on the battery being charged, among other things. In order for my design to work right, I&#8217;ll need to know when the battery is full, when it needs current-limited charging, and when it needs a boost because the motor is running. So I strapped a $5 digital voltmeter to the headset to monitor the battery voltage under various conditions. \u00a0Here is what I found.<\/p>\n<table border=\"1\">\n<tbody>\n<tr>\n<th>Condition<\/th>\n<th>Voltage<\/th>\n<\/tr>\n<tr>\n<td>Fully charged, with charger connected<\/td>\n<td>31.8<\/td>\n<\/tr>\n<tr>\n<td>Fully charged, charger just disconnected<\/td>\n<td>26.8<\/td>\n<\/tr>\n<tr>\n<td>Fully charged, after motor run just a little<\/td>\n<td>25.8<\/td>\n<\/tr>\n<tr>\n<td>Upon motor startup (high torque acceleration)<\/td>\n<td>21.9<\/td>\n<\/tr>\n<tr>\n<td>After 10-20 sec, motor running at terminal speed<\/td>\n<td>23.5<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>Those readings were taken with the old, weak batteries. I should redo the experiment now that fresh batteries have been installed. But this data gives me encouragement that my power transfer circuit can work by monitoring battery voltage alone.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>A battery charger generally needs to know the voltage on the battery being charged, among other things. In order for my design to work right, I&#8217;ll need to know when the battery is full, when it needs current-limited charging, and when it needs a boost because the motor is running. So I strapped a $5 &hellip; <a href=\"http:\/\/pididu.com\/wordpress\/solarbike\/monitoring-battery-voltage\/\" class=\"more-link\">Continue reading <span class=\"screen-reader-text\">Monitoring Battery Voltage<\/span> <span class=\"meta-nav\">&rarr;<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":25,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[2],"tags":[],"_links":{"self":[{"href":"http:\/\/pididu.com\/wordpress\/solarbike\/wp-json\/wp\/v2\/posts\/24"}],"collection":[{"href":"http:\/\/pididu.com\/wordpress\/solarbike\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/pididu.com\/wordpress\/solarbike\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/pididu.com\/wordpress\/solarbike\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/pididu.com\/wordpress\/solarbike\/wp-json\/wp\/v2\/comments?post=24"}],"version-history":[{"count":0,"href":"http:\/\/pididu.com\/wordpress\/solarbike\/wp-json\/wp\/v2\/posts\/24\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"http:\/\/pididu.com\/wordpress\/solarbike\/wp-json\/wp\/v2\/media\/25"}],"wp:attachment":[{"href":"http:\/\/pididu.com\/wordpress\/solarbike\/wp-json\/wp\/v2\/media?parent=24"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/pididu.com\/wordpress\/solarbike\/wp-json\/wp\/v2\/categories?post=24"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/pididu.com\/wordpress\/solarbike\/wp-json\/wp\/v2\/tags?post=24"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}