12v, 7Ah Smart Battery Charger with PCB Diagram

[@Hkmmotologs]

The charge and full keeps turned on at the same time when it's close to full charge (or maybe charged) and the charging led doesn't turn off.. I tried calibrating it multiple times and I am using 3296 multi turn precision trim pot and I am charging two 7ah batteries in parallel. using LM350K instead of 317 for 3A capability.. Input is 24V Transformer

[@moelwinoo2095]

Hi sir ,I think your adjust is wrong .First adjust is vr2 at 13.6v. Second adjust vr3 to charge led begin glow.This is setup float charge not readjust Vr3.Third adjust is 0.5v vr1 and readjust the vr2 at 14.1v.My discuss may me wrong.

[@Hkmmotologs]

Hi , Can i Use 50K trim pot for VR3 instead of 20K?.. does it affect the circuit ?

[@Bestengineeringprojectsbep]

Hi harikrishnan, you can use 50k trim pot instead of 20k. This variable resistor is used for reference purposes thus you have to take care while adjusting.

[@Hkmmotologs]

@@Bestengineeringprojectsbep Ok thank you.. the store near me didn't have any 20K pots.. they told me to use 50K instead.. I just wanted to confirm with you befor assembling :)

[@Bestengineeringprojectsbep]

@@Hkmmotologs please let us know. While adjusting you have to take care because value of resistance change rapidly with little change in wiper ppsition of preset. happy working 😊

[@Hkmmotologs]

@@Bestengineeringprojectsbep Sure, will do.. I am using 50K 3296W type multi turn trimpot for more control. VR1 and VR2 normal wiper Trims 3386P type.

[@Hkmmotologs]

@@Bestengineeringprojectsbepi made the circuit, it's working but when battery is charged, the green led glows but also the charging led also stays dimly glowing. never fully off.. why is that?