This thread has been locked.
If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.
Hi Sir,
When the system power load increases, the Charger IC cannot be charged
The conditions are as follows
Adapter: 19V, 7.89A
when Rac seting 0.01Ohm and on Rac voltage as below:
1. At 40% system loading, 37.8mV, the battery can be charged 0.5A
2. At 60% system loading, 45mV, the battery can be charged 0.5A
3. At 100% system loading, 58.1mV, the battery cannot be charged
there any errors in the setting of the attached theschematic? Is the schematic correct? please kindly let us learn from you and suggestion to us.
Hi, Tommy,
There is an input current register 0x3F, its default value is 4.096A. From schematic, the ILIM pin is limit to 3.05A. You may run into input current limit, thus limiting your charge current.
Datasheet 7.6.11, "The total input current, from a wall cube or other DC source, is the sum of the system supply current and the
current required by the charger. When the input current exceeds the set input current limit, the bq24780S device
decreases the charge current to provide priority to system load. As the system current rises, the available charge
current drops linearly to 0."
Hi Tiger:
I am ESVS James Liu
The schematic is my company project
The BQ24780S register setting
0x12H 8108
0x3BH C210
0x38H 0384
0x37H 1A40
0x3CH 4A54
0x3DH 8120
0x3AH 0020
0x14H 0200
0x15H 41A0
0x39H 2600
0x3FH 1E80 7808mA
The Rac is 58.1mV , So input current is 5.81A < 7.8A
Can you help me?
Hi, James,
Please check your battery voltage as well. Does this happen at fully-charged battery or low-charged battery? If fully-charged, the charge current may terminate when max charge voltage is reached.
Could you get 3A charge current when the system load is zero? or Could you measure the SRN voltage and report back?
It looks like a test setup issue. Please refine your test setup and use adequate wire gauge for high current test.