Introduction: Li - Ion Battery Level Indicator

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.

This circuit is design to measure 3.7V rechargeable batteries level.

4.2V - 100%; 4V - 80%; 3.8V - 60%; 3.6V - 40%; 3.4V - 20%

LED1 - RED; LED2 - YELLOW; LED3 - YELLOW; LED4 - GREEN; LED5 - GREEN

D1 is used to protect a circuit from the battery being placed wrong way. You can use 1N4007 or something similar.

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.

LM339 datasheet: http://www.onsemi.com/pub_link/Collateral/LM339-D...

The circuit for 12V battery level indicator was found on http://www.electroschematics.com/6868/12v-battery...

but with the changes was made to measure 3.7V batteries.

Comments

author
ChochoR made it!(author)2017-06-11

I have a 3s3p battery pack 18650 and i have a voltage meter as well. If i understood correctly the instructions, it should be like this:


20% 40% 60% 80% 100%

10,2V 10,8V 11,4V 12V 12,6V

(3*3.4) (3*3.6) (3*3.8) (3*4) (3*4.2)

Am I Correct?


author
LenarOX made it!(author)2017-04-06

I think this doesn't work without a zener diode because the battery voltage changes and the reference voltage too

author
gsmhack made it!(author)2017-04-11

yep, thats what I think, too... Aaaaand, yes, the original 12V version used a zener... This circuit is useless.. :(

author
rahuldj made it!(author)2017-01-16

Hi , This is very useful, can you please send PCB design and schematic at rahul.jinralkar@gmail.com? Or post it here itself

author
leodemon made it!(author)2016-12-01

need a circuit which shows battery level during charging, for charging purpose consider a simple nokia lion bat charger which produce around 5 V

author
gaurav_23 made it!(author)2016-09-01

Will it work for li-ion battery pack in 4S?

author
kamhagh made it!(author)2016-08-21

Don't resistors only limit current? And doesnt the - on the comparators change as battety voltage drops?

Anyway to get more accurate readings to my arduino? I want to be able to tell percantage

author
Vitor+HugoC made it!(author)2016-08-02

PCB Please :)
vitorhchavesc@gmail.com

author
SubhodipM made it!(author)2016-07-26

hello....can i use it in 7.4v circuit?? if not...then any suggestions.... NEED HELP..

author
jchristakis made it!(author)2016-02-16

is there any way i can regulate the margins of voltage that the leds are working? meaning, when i put it on a simulator, it works for voltages 3.7V to 4V. is there any formula to calculate the R1 and R2 or any other resistors needed for a lower margin 2V to 4.8V?

author
jchristakis made it!(author)2016-02-17

nevermind my previous comment. i m so nab i totally missed to consider kirchoff's laws.... i am designing the pcb now . message me anyone for a copy if you want it.

author
acidkidd made it!(author)2016-06-07

Please sendme the PCB design Thank you

info@digico.in

author
FatihF2 made it!(author)2016-05-18

hi i try it in Proteus program and its working but when its 3,7 v its all led are on but they are dim and when giving more then 3,7 v until 4,2 its just all leds is on and just giving more brightness. why is that

author
DejfM made it!(author)2016-05-16

Hi, can you pls send me schamatic? dejfmastejn@gmail.com thank you very much

author
MoezT made it!(author)2016-02-06

can you send me pcb secheme ,lllmoez@yahoo.fr ,i release the circuit in

BREADBOARD

but wan't work

author
FahmiN4 made it!(author)2016-01-27

Could I get the PCB Scheme? Send to my email : fahminlb33@gmail.com

author
RaulE3 made it!(author)2015-08-29

Hello, this apply the same way for batteries Li-Po. Thank's

author
amiir made it!(author)2015-07-06

can u please upgrade this circuit for 6V battery?

author
ijo3000 made it!(author)2015-05-06

Could i also get a list of parts if possible please? ijo9109@gmail.com

author
Zatara11 made it!(author)2015-04-12

This was a great addition to the power bank I made. Thanks for the Instructable. The link is a video to show the button working.

http://youtu.be/4QShZWcQaJg

image.jpg
author
nishants3 made it!(author)2015-03-19

can u pls send the list of things used in this because i cannot understand but i want to make it so pls send it to singhnishant530@gmail.com

author
rwisecup made it!(author)2015-02-10

This is great! I've been looking for something like this for a few hours now.

author
seamster made it!(author)2014-10-21

Thanks for sharing this!

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