Good evening everyone, I'm new here and I wish to get help for the little challenges I'm having with multisim

I watched this circuit online and it works perfectly well, I'm trying to replicate the circuit for a project but I want to stimulate it first. Having connected it properly as shown, the circuit fails to do anything. No error code and none of the LEDs are working. The circuit is meant to stimulate low battery (red LED) and full battery(Green LED) in a 18650 3.7v Lithium-ion battery.

I've tried different circuits that work perfectly online but none is stimulating. What am I doing wrong, please?

Note: The stimulation software is multisim

Attached below is the multisim image and the circuit image itself.

Thanks

 

Sorry, but I don't see how that circuit can work.
It has no feedback from the voltage across the battery to control the charging current.
The TL431 feedback just goes to the +5V supply voltage, so is unaffected by the battery voltage.

If the online circuit works, it's not the one you posted.

 

Sorry, but I don't see how that circuit can work.
It has no feedback from the voltage across the battery to control the charging current.
The TL431 feedback just goes to the +5V supply voltage, so is unaffected by the battery voltage.

If the online circuit works, it's not the one you posted

What modification can I make to make it works properly

Thanks

 

It's a bad circuit- from the messy land of the internet.

I would discard it and start over- unless you like exploding batteries?

 

It's a bad circuit- from the messy land of the internet.

I would discard it and start over- unless you like exploding batteries?

Do you have any better circuit recommendations I'm really lost here

 

I would look at the many chipsets that are made for purpose.
You have not explicitly mentioned the battery chemistry, you must be very careful to charge the battery properly- for the specific type.

Google "battery charger IC for LiFePO4"

 

The battery mentioned is a 18650 "3.7V" type which is an older chemistry Li-Ion type.
A LiFePO4 type is usually listed at 3.2V.

 

A proper design will sense, Vbat, Ibat and CC, CV charge rate with shutoff < 5%CC.