Voltage Divider Battery Sensing - No Change to Readings?

hello, it's me again. question i'm hoping can me please.


the project i'm working on @ moment going powered 12v 7ah sealed lead acid battery (model: np7-12tfr if helps).

i want project monitor own battery health turned library i've found on github called battery sense. https://github.com/rlogiacco/batterysense

i using dc-dc converter step down 12v 5v powering project built sensing circuit based on sections: higher 5v, external voltage regulator , higher 5v, activated on demand.

what ended on demand circuit placed between battery , dc-dc converter shown in higer 5v external regulator.


i'm i've followed every instruction letter including recommended voltagereference calibration , getting reading doesn't appear changing.
yesterday freshly charged battery @ 13.314v according battery sense sketch , today reads same?

i verified reading yesterday against multi-meter , pretty darn close today multi-meter showing 13.093v sketch still says it's 13.314v.


i have checked, checked , triple checked circuit wiring mistaks may have made wiring on breadboard far can tell have reproduced circuit , values resistors correct. have verified ratio values correct in library true voltage. have defined correct upper , lower (min max) battery values , pins used wired correct places.

i can't understand why reported voltage isn't showing drop.

basically circuit simple voltage divider rated handle / read 12v batteries , it's switched in , out of circuit using 2n7000 mosfet. appears working except readings don't seem changing @ all.


obviously know these battery monitors aren't super reliable or super accurate due many influential factors , variables want rough idea of battery doing.


sorry if that's not enough or information. if more information needed diagnose problem ask , i'll best provide it. in mean time i'm going keep working problem myself. naturally if bottom of before has answer, i'll post solution.


many thanks!


thanks!

give try voltage divider.

try , discharge battery bit more.

and reading without library , see get.

ps switching via mosfet dumb design. because of clamping diodes in arduino voltage can float 5,5v. assume used 22k r1? battery of 13,3v still have (13,3v - 5,5v) / 22k = 0,35ma drain. doesn't sound lot when turned "on" draws 13,3v / (22k + 10k) = 0,42ma. that's saving of 70ua...

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