Hi, I'm developing dual power source device. 1st source is 12.4V adapter, the 2nd is 12v DELTA battery. PowerPath Controller is LTC4418. So the problem is that power consumption of LT1512 from supply more than 200mA and only 5mA goes to battery. Current is always about 5mA when battery fully discharged and also when battery is fully charged. With this issue because of low output current controller can't fully charge battery and charging time is very very sloooow. I charged my battery from 10.5v to 13.35v about 36 hours.Voltage limitter is set to 13,75V using R1 and R3 on my schematics and current is limited to 200mA using R5 with nominal 0,5 Ohm which was calculated using this formula: 100mV / 0,5Ohm = 200mA on page #7 of datasheet. Charging stops at 13.35V. But when I disconnect battery from the output, I see 13,75V on controller's output without load. I checked soldering on PCB 100 times, also I replaced all components twice except LT1512 because this controller is very expensive in Belarus (~$20). Also I tried to solder two 0,5Ohm resistors in parallel to increase charging current from 200mA to 400mA, but absolutelly nothing changed! Consumption from power supply is about 190-230mA and output of LT1512 is 5mA. And temperature of LT1512 is about 80C. Also I tried to charge battery to 100% (13,8v) using another charger and then I connected fully charged battery to LT1512. The result is: power consumption from power supply is about 12mA and 1-3mA delivers to battery from LT1512 to prevent discharge. So, the questtion is how to fix issue with low current output from LT1512? Thanx a lot.
L1 - Bourns SRF1260A-330M
R5 - Susumu RL1220S-R50-F
R6, R7 - Welwyn ULR15S-R005FT2
C2 - Wurth Elektronik 875075555003
C4, C5 - Panasonic EEEFK1E102AQ
All other capacitors are Murata X7R or NP0
All other resistors are Yageo 1%