Hi Folks,
I am Using the ADP2291 . I have two circuits parallel which they are Isolated with BAT1000 to support the system .
I am using Sanyo Battery 18650(4.1~3.7 V ,2800mA).
I used the application circuit with HERMAL PROTECTION, figure 25 on data sheet .
The only difference is RS value which is 0.15 ohm to increase the charging current at the beginning .
Single circuit ,(100% Discharged Batt)Power up the circuit will draw 1500 mA as expected . after 10 minutes Led goes to off mode. Input current draw by source is reaching to 400 ma after 15 min . I expect to charging continue for at least 2 hours with approximately 1300 mA to full charge the battery .
input voltage is 5.04 v---4.74 V is the voltage before on RS In-Pin ,100 mV drops cross the RS . VCE = 0.922 ---VB =3.74V
V ADJ = 2.145v
V CHG = 3.69 ,V between the Resistor and LED is 3.69 V ...No current drawn .
Note : I placed the NTC close to the Pin of the Batt . Temp of the battery is not exceed the 95 degree F (Measured )
Why the circuit goes to shutdown status very quick ?
Picture is attached .
Thanks for Help
Ash
Is anyone here to answer ?
Hi Ash,
Sorry for the late response. Would you try the followings for debugging?
1) Increase the input voltage to 12V. Is the problem still there?2) will it work if you use single ADP2291 charger to battery?3) Try to use a normal resister instead of NTC resister as the impedance may vary a lot with different beta and type.
Thanks,
Hong
Hong,
1) Increase the input voltage to 12V. Is the problem still there? It is not possible ,My input is solid +5.0 V ,If even does work ,I cant increase the Vin.2) will it work if you use single ADP2291 charger to battery? NO.Those Circuits are isolated and does work individual. I did test for single board all time to make sure the concept works ,But still I have problem . 3) Try to use a normal resister instead of NTC resister as the impedance may vary a lot with different beta and type. Already, I removed the NTC totally and make the pin float .similar to the simple circuit ! No luck
Thanks
Please try to increase Vin to see whether there is Under Voltage Lock Out issue. your input voltage is 4.7V, which is very close to the minimum spec 4.5V.
I believe when Vin is above the minimum ,circuit should work properly regardless of any other condition .