My customer is using UC3906 for charging a Lead Acid Battery. (12V/ !2AH) . He has designed the circuit using the equations given in the datasheet.
Charging current is 700mA,
Over voltage is 14.4v,
V12 is 13.6v,
Floating voltage is 13.5v,
V31 is 12.15v.
Below is the issue that he has sent to me
"Actually up to the V12(I.e. 13.6v) charging current should be 700mA,after that it should be suddenly down to 70mA,But in our circuit the battery voltage reaches to the 13v then the charging current is slowly going down and the battery voltage is increasing. Over voltage control and floating voltage is not happening in the circuit"
Actually, his charging voltage is not stopping at 14.4V for which it is designed for. He has measured this voltage up to 14.6V. Also, the current is not dropping down to 70mA.
I have attached his schematic.
