https://roboticsclub.org/redmine/https://roboticsclub.org/redmine/redmine/favicon.ico2010-01-22T21:18:35ZRobotics ClubColony Scout - Bug #1044: Choose a new rtc backup batteryhttps://roboticsclub.org/redmine/issues/1044?journal_id=26442010-01-22T21:18:35ZKevin Woo
<ul></ul><p><a class="external" href="http://www.allspectrum.com/store/product_info.php?cPath=76_156&products_id=576&osCsid=f6ab02f15e80a8597fbd2cce9064f1fe&sdesc=CR1216+3v+Lithium+Button+Cell+Battery%2C+Renata+%3D%3DSHIPS+GROUND+ONLY%3D%3D+Model+%23+RENATA-CR1216">http://www.allspectrum.com/store/product_info.php?cPath=76_156&products_id=576&osCsid=f6ab02f15e80a8597fbd2cce9064f1fe&sdesc=CR1216+3v+Lithium+Button+Cell+Battery%2C+Renata+%3D%3DSHIPS+GROUND+ONLY%3D%3D+Model+%23+RENATA-CR1216</a></p>
<p>$0.75 / battery, 3V we need to step it down but its the best we can do. Uses existing battery holder</p> Colony Scout - Bug #1044: Choose a new rtc backup batteryhttps://roboticsclub.org/redmine/issues/1044?journal_id=26452010-01-22T21:30:06ZKevin Woo
<ul></ul><p>Wikipedia says that the typical capacity is 25mAh with our current draw of 5uA. This leads to about 208 days of running only on the battery. There is also a self discharge of .1mA. This may dramatically lessen the lifetime of the battery.</p>
<p>Alternatively we can use: <a class="external" href="http://www.allspectrum.com/store/product_info.php?cPath=76_156&products_id=1589&osCsid=f6ab02f15e80a8597fbd2cce9064f1fe&sdesc=CR1220+3.0V+Lithium+Button+Cell+Battery%2C+38mAh%2C+%281pcs%2Fbl%29+%3D%3DSHIPS+GROUND+ONLY%3D%3D+Model+%23+CR1220-BP1">http://www.allspectrum.com/store/product_info.php?cPath=76_156&products_id=1589&osCsid=f6ab02f15e80a8597fbd2cce9064f1fe&sdesc=CR1220+3.0V+Lithium+Button+Cell+Battery%2C+38mAh%2C+%281pcs%2Fbl%29+%3D%3DSHIPS+GROUND+ONLY%3D%3D+Model+%23+CR1220-BP1</a></p>
<p>This is a 1220 but has a capacity of 36mAh which gives us 316 days. It costs $0.99 each.</p> Colony Scout - Bug #1044: Choose a new rtc backup batteryhttps://roboticsclub.org/redmine/issues/1044?journal_id=26462010-01-22T22:07:56ZKevin Woo
<ul></ul><p>Using 2 diode drops. Schottky and standard diode -> .3 + .7 in the worst case leads to 2V which is a little dangerous. Common case will be .8 + .4 which leads to exactly 1.8V.</p>
<p>Diode:<br /><a class="external" href="http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=641-1002-1-ND">http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=641-1002-1-ND</a></p> Colony Scout - Bug #1044: Choose a new rtc backup batteryhttps://roboticsclub.org/redmine/issues/1044?journal_id=27312010-02-07T02:04:36ZKevin Woo
<ul><li><strong>Status</strong> changed from <i>Assigned</i> to <i>Fixed</i></li></ul><p>We're going with the CR1220. Added to both BOMs</p>