# Need help for battery charging circuit

#### sudharshan.panduranga

Joined Apr 10, 2008
61
Hi....
Can any one give idea for Battery charging circuit to meet following requirement.
I am using 3.6v/600mAH rechargeable battery. This will charge from +5V DC supply.

1. When the Battery is fully discharged, the +5v supply should provide 23mA current to charge the battery till it reaches +3V.

2. After It reaches +3V the battery should consume required current.

#### iamspook

Joined Aug 6, 2008
27
Hi....

2. After It reaches +3V the battery should consume required current.
What it meant by 'consume required current'? Is this battery running a circuit while being charged? or is it a stand-alone charger?

#### nanovate

Joined May 7, 2007
666
need to know what kind of battery also...

Look at bq2057 from TI for lithium-ion batteries

+5v supply should provide 23mA current to charge the battery
why 23mA?

#### sudharshan.panduranga

Joined Apr 10, 2008
61
What it meant by 'consume required current'? Is this battery running a circuit while being charged? or is it a stand-alone charger?
The current limiting circuit is required till it charges to 3V.
After it reaches 3V, Current limiting circuit should be inactive.
Direct +5V should charge the Battery after it reaches +3V.

#### sudharshan.panduranga

Joined Apr 10, 2008
61
need to know what kind of battery also...

Look at bq2057 from TI for lithium-ion batteries

why 23mA?
My project is Power supply generation module to get +15VDC from Line 3 phase CTs. I have derived +5V, +8V, +12V from the +15V constant voltage.
I should get +15VDC constant voltage when Primary 3 phase Line current reaches 1A.
*If Battery is connected to +5V directly, it can't get +15V at 1A current bcause of Battery current consumption.
* Thiswill work if i adjust the battery current to 23mA around value.

#### srisuresh

Joined Nov 29, 2011
2
Hello sir..

I need a battery charging circuit diagram.

Actually me planned to implement by using this circuit but some components are not available.

So please tell a circuit diagram for charging 9V battery.

THANK YOU