<div class="photoset-item photoset-cell" data-imagenotes="[{&quot;noteID&quot;:&quot;NGDTSPEI1IQB32G&quot;,&quot;author&quot;:&quot;osvaldas.banys&quot;,&quot;text&quot;:&quot;RED&quot;,&quot;top&quot;:0.18026565464895636,&quot;left&quot;:0.13768115942028986,&quot;height&quot;:0.09487666034155598,&quot;width&quot;:0.09057971014492754},{&quot;noteID&quot;:&quot;NTIG0TNI1IQB39I&quot;,&quot;author&quot;:&quot;osvaldas.banys&quot;,&quot;text&quot;:&quot;Add a button here&quot;,&quot;top&quot;:0.018975332068311195,&quot;left&quot;:0.161231884057971,&quot;height&quot;:0.06072106261859583,&quot;width&quot;:0.04710144927536232},{&quot;noteID&quot;:&quot;N1QH4PBI1IQB39U&quot;,&quot;author&quot;:&quot;osvaldas.banys&quot;,&quot;text&quot;:&quot;GREEN&quot;,&quot;top&quot;:0.06072106261859583,&quot;left&quot;:0.5942028985507246,&quot;height&quot;:0.09487666034155598,&quot;width&quot;:0.09057971014492754},{&quot;noteID&quot;:&quot;N00TTCSI1IQB3AE&quot;,&quot;author&quot;:&quot;osvaldas.banys&quot;,&quot;text&quot;:&quot;GREEN&quot;,&quot;top&quot;:0.06261859582542695,&quot;left&quot;:0.7101449275362319,&quot;height&quot;:0.09487666034155598,&quot;width&quot;:0.09057971014492754},{&quot;noteID&quot;:&quot;NWOS7XSI1IQB3AF&quot;,&quot;author&quot;:&quot;osvaldas.banys&quot;,&quot;text&quot;:&quot;YELLOW&quot;,&quot;top&quot;:0.056925996204933584,&quot;left&quot;:0.8134057971014492,&quot;height&quot;:0.09487666034155598,&quot;width&quot;:0.09057971014492754},{&quot;noteID&quot;:&quot;N24EYYLI1IQB3AJ&quot;,&quot;author&quot;:&quot;osvaldas.banys&quot;,&quot;text&quot;:&quot;YELLOW&quot;,&quot;top&quot;:0.05502846299810247,&quot;left&quot;:0.9021739130434783,&quot;height&quot;:0.11195445920303605,&quot;width&quot;:0.09057971014492754}]" style="padding: 2.5px; color: #333333; font-family: &quot;Helvetica Neue&quot;, Helvetica, Arial, sans-serif; font-size: 14px; text-align: center; background-color: #ffffff; flex: 1.04676 1 0%;">
   <div class="photoset-image" style="position: relative; overflow: hidden; border-radius: 4px; height: 684.672px;"><a class="gallery-link" rel="photoset58" href="https://content.instructables.com/ORIG/FLG/CU7O/I1IQAX36/FLGCU7OI1IQAX36.png?auto=webp&amp;frame=1&amp;fit=bounds&amp;md=dd0a742dfebd5fc08efbdcca6ffe72f5" data-download="https://content.instructables.com/ORIG/FLG/CU7O/I1IQAX36/FLGCU7OI1IQAX36.png?auto=webp&amp;frame=1&amp;md=dd0a742dfebd5fc08efbdcca6ffe72f5" data-fileid="FLGCU7OI1IQAX36" style="color: #e86c00; text-decoration-line: none;" target="_blank"><img class=" ls-is-cached lazyloaded" alt="Li - Ion Battery Level Indicator" src="https://content.instructables.com/ORIG/FLG/CU7O/I1IQAX36/FLGCU7OI1IQAX36.png?auto=webp&amp;frame=1&amp;fit=bounds&amp;md=dd0a742dfebd5fc08efbdcca6ffe72f5" data-src="https://content.instructables.com/ORIG/FLG/CU7O/I1IQAX36/FLGCU7OI1IQAX36.png?auto=webp&amp;frame=1&amp;fit=bounds&amp;md=dd0a742dfebd5fc08efbdcca6ffe72f5" style="max-width: 100%; height: 684.672px; vertical-align: middle; border: 0px; background: none; object-fit: cover; width: 716.703px; border-radius: 4px;" /><i class="notes-icon" style="background: url(&quot;../img/imagenotes/icon-notes.png&quot;) no-repeat; width: 25px; height: 25px; display: inline-block; position: absolute; right: 0px; top: 0px;"></i></a></div>
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      <div class="photoset-image" style="position: relative; overflow: hidden; border-radius: 4px; height: 321.203px;"><a class="gallery-link" rel="photoset58" href="https://content.instructables.com/ORIG/FUL/4I9J/I1IQB1IB/FUL4I9JI1IQB1IB.png?auto=webp&amp;frame=1&amp;fit=bounds&amp;md=b460cdf8630a049b39044f55b2d515a7" data-download="https://content.instructables.com/ORIG/FUL/4I9J/I1IQB1IB/FUL4I9JI1IQB1IB.png?auto=webp&amp;frame=1&amp;md=b460cdf8630a049b39044f55b2d515a7" data-fileid="FUL4I9JI1IQB1IB" style="color: #e86c00; text-decoration-line: none;" target="_blank"><img class=" ls-is-cached lazyloaded" alt="Li - Ion Battery Level Indicator" src="https://content.instructables.com/ORIG/FUL/4I9J/I1IQB1IB/FUL4I9JI1IQB1IB.png?auto=webp&amp;frame=1&amp;crop=3:2&amp;fit=bounds&amp;md=b460cdf8630a049b39044f55b2d515a7" data-src="https://content.instructables.com/ORIG/FUL/4I9J/I1IQB1IB/FUL4I9JI1IQB1IB.png?auto=webp&amp;frame=1&amp;crop=3:2&amp;fit=bounds&amp;md=b460cdf8630a049b39044f55b2d515a7" style="max-width: 100%; height: 321.203px; vertical-align: middle; border: 0px; background: none; object-fit: cover; width: 478.297px; border-radius: 4px;" /></a></div>
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      <div class="photoset-image" style="position: relative; overflow: hidden; border-radius: 4px; height: 358.469px;"><a class="gallery-link" rel="photoset58" href="https://content.instructables.com/ORIG/FX1/DADA/I1IQB3NK/FX1DADAI1IQB3NK.jpg?auto=webp&amp;frame=1&amp;width=1024&amp;height=1024&amp;fit=bounds&amp;md=16b38f389d78d921c98c0aa34518db9e" data-download="https://content.instructables.com/ORIG/FX1/DADA/I1IQB3NK/FX1DADAI1IQB3NK.jpg?auto=webp&amp;frame=1&amp;md=16b38f389d78d921c98c0aa34518db9e" data-fileid="FX1DADAI1IQB3NK" style="color: #cf6000; outline: 0px; cursor: pointer;" target="_blank"><img class=" ls-is-cached lazyloaded" alt="Li - Ion Battery Level Indicator" src="https://content.instructables.com/ORIG/FX1/DADA/I1IQB3NK/FX1DADAI1IQB3NK.jpg?auto=webp&amp;frame=1&amp;width=483&amp;height=1024&amp;fit=bounds&amp;md=16b38f389d78d921c98c0aa34518db9e" data-src="https://content.instructables.com/ORIG/FX1/DADA/I1IQB3NK/FX1DADAI1IQB3NK.jpg?auto=webp&amp;frame=1&amp;width=483&amp;height=1024&amp;fit=bounds&amp;md=16b38f389d78d921c98c0aa34518db9e" style="max-width: 100%; height: 358.469px; vertical-align: middle; border: 0px; background: none; object-fit: cover; width: 478.297px; border-radius: 4px;" /></a></div>
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<p style="margin-top: 3px; margin-bottom: 20px; max-width: 100%; counter-reset: list-1 0 list-2 0 list-3 0 list-4 0 list-5 0 list-6 0 list-7 0 list-8 0 list-9 0; color: #555555; background-color: #ffffff;"><span style="font-family: arial; font-size: 14px;">Are you looking for a simple circuit to measure your Lithium Ion single cell charging and discharging level? Here is one chip circuit, powered up from the same Lithium Ion battery you want to measure.</span></p>
<p style="margin-top: 3px; margin-bottom: 20px; max-width: 100%; counter-reset: list-1 0 list-2 0 list-3 0 list-4 0 list-5 0 list-6 0 list-7 0 list-8 0 list-9 0; color: #555555; background-color: #ffffff;"><span style="font-family: arial; font-size: 14px;">This circuit is design to measure 3.7V rechargeable batteries level.</span></p>
<p style="margin-top: 3px; margin-bottom: 20px; max-width: 100%; counter-reset: list-1 0 list-2 0 list-3 0 list-4 0 list-5 0 list-6 0 list-7 0 list-8 0 list-9 0; color: #555555; background-color: #ffffff;"><span style="font-family: arial; font-size: 14px;">4.2V - 100%; 4V - 80%; 3.8V - 60%; 3.6V - 40%; 3.4V - 20%</span></p>
<p style="margin-top: 3px; margin-bottom: 20px; max-width: 100%; counter-reset: list-1 0 list-2 0 list-3 0 list-4 0 list-5 0 list-6 0 list-7 0 list-8 0 list-9 0; color: #555555; background-color: #ffffff;"><span style="font-family: arial; font-size: 14px;">LED1 - RED; LED2 - YELLOW; LED3 - YELLOW; LED4 - GREEN; LED5 - GREEN</span></p>
<p style="margin-top: 3px; margin-bottom: 20px; max-width: 100%; counter-reset: list-1 0 list-2 0 list-3 0 list-4 0 list-5 0 list-6 0 list-7 0 list-8 0 list-9 0; color: #555555; background-color: #ffffff;"><span style="font-family: arial; font-size: 14px;">D1 is used to protect a circuit from the battery being placed wrong way. You can use 1N4007 or something similar.</span></p>
<p style="margin-top: 3px; margin-bottom: 20px; max-width: 100%; counter-reset: list-1 0 list-2 0 list-3 0 list-4 0 list-5 0 list-6 0 list-7 0 list-8 0 list-9 0; color: #555555; background-color: #ffffff;"><span style="font-family: arial; font-size: 14px;">When this circuit was simulated on LTSpice, I used R1 value 18k, however, after this circuit was soldered on a printBoard, this value was to high, so i had to change it to 15k. It might be because of inaccuracy of the other resistor values.</span></p>
<p style="margin-top: 3px; margin-bottom: 20px; max-width: 100%; counter-reset: list-1 0 list-2 0 list-3 0 list-4 0 list-5 0 list-6 0 list-7 0 list-8 0 list-9 0; color: #555555; background-color: #ffffff;"><span style="font-family: arial; font-size: 14px;">LM339 datasheet:&nbsp;</span><a href="http://www.onsemi.com/pub_link/Collateral/LM339-D.PDF" rel="nofollow" target="_blank" style="color: #1e8439; max-width: 100%; overflow-wrap: break-word; cursor: pointer; word-break: break-word; hyphens: auto;"><span style="font-family: arial; font-size: 14px;">http://www.onsemi.com/pub_link/Collateral/LM339-D...</span></a></p>
<p style="margin-top: 3px; margin-bottom: 20px; max-width: 100%; counter-reset: list-1 0 list-2 0 list-3 0 list-4 0 list-5 0 list-6 0 list-7 0 list-8 0 list-9 0; color: #555555; background-color: #ffffff;"><span style="font-family: arial; font-size: 14px;">The circuit for 12V battery level indicator was found on&nbsp;</span><a href="http://www.electroschematics.com/6868/12v-battery-level-indicator-circuit/" rel="nofollow" target="_blank" style="color: #1e8439; max-width: 100%; overflow-wrap: break-word; cursor: pointer; word-break: break-word; hyphens: auto;"><span style="font-family: arial; font-size: 14px;">http://www.electroschematics.com/6868/12v-battery...</span></a></p>
<p style="margin-top: 3px; margin-bottom: 20px; max-width: 100%; counter-reset: list-1 0 list-2 0 list-3 0 list-4 0 list-5 0 list-6 0 list-7 0 list-8 0 list-9 0; color: #555555; background-color: #ffffff;"><span style="font-family: arial; font-size: 14px;">but with the changes was made to measure 3.7V batteries.</span></p>