designing switch mode mobile battery charger

[ahcraton]

i want to make a switch mode battery charger for li-ion battery of mobile.i need a circuit diagram and i want to use microcontroller to stop the charging automatically after some time and to stop charging if over temperature occurs

 

[BradtheRad]

1.

Li-Ion type require greater care as to charging them, compared to more tolerant types such as nicads and nimh.

If the charge current is small, then linear drop (resistor or transistor) may be adequate. Perhaps safer too. A switching supply will need great care in designing it, so there is no chance of exposing the batteries to overmuch voltage or current.

2.

To monitor temperature, consider using 2 sensors, and compare their readings. One sensor against the battery pack, the other for ambient surroundings.

 

[tpetar]

i want to make a switch mode battery charger for li-ion battery of mobile.i need a circuit diagram and i want to use microcontroller to stop the charging automatically after some time and to stop charging if over temperature occurs

You can use cheap dedicated chip for this purpose MCP73832. Complete circuit require very small space and minimal number of parts are used, can be 10mm x 10mm or even smaller, maximum charging current is 500mA what is enough for mobile phone battery.



On this photo on other side I make small DC/DC Li-Po to 5V converter for 100mA-350mA, 96% efficiency.


;-)

 

[ahcraton]

my battery is of 1300 mAh.

 

[tpetar]

my battery is of 1300 mAh.

You can charge your battery with this, select 450mA current for charging and time for charging is near 3h. Also there is other IC like this what I use with higher currents.

 

[ahcraton]

i want to charge fast

 

[tpetar]

You can use other IC with higher charging current like I mention before.

You can find ICs for higher currents:

Microchip products for battery management
https://www.microchip.com/ParamChartSearch/chart.aspx?branchID=9011&mid=10&lang=en

For example for 1A MCP73833, MCP73834, ...