Help me... LTC4006 battery charger circuit not working

[udhay_cit]

I need to design a charger circuit for 4 cell Li-Ion battery. I am using 4 individual 3.7V /1100mAH Li-Ion battery's are connected in series. So i am using LTC4006-4 charger ic for my application. I am using 19V/3A dell laptop SMPS as charger input. My charge current is 1A.

When i connect 19v input to the circuit, i can get 18.6V at battery end(without connecting the battery) & the output voltage should be at this condition is 16.968V maximum . If i connect a resistor(1k or 2k) at the output, the voltage goes to zero. If i connect the battery then the battery terminal shows only the battery voltage(previously 18.6v) & no current taken from the source. Charge status showing always zero. I assembled two number of PCB'S but same result.....

Please help me to find-out the problem...

Regards
Udhay

 

[dustie]

It's hard to say what is the problem.... According to your description - maybe the batteries should be discharged ! If the batteries are not discharged enough, the charger might not be current source.
Also check the voltage on the CLN pin (input put) and the INFET pin (output pin).

 

[Matias Pretel]

I have the same problem. Did you find the answer? please let me know.

best regards!

 

[amayilsamy]

Hi..
1. Check after connecting 2 pin (CHG) in ground.
2. Discharge some amount of current from battery then check again