# can any one help...........

Discussion in 'General Electronics Chat' started by n_prithivi, Jan 4, 2009.

1. ### n_prithivi Thread Starter New Member

Jan 4, 2009
2
0
i am doing a project 'solar mobile charger' i have a 3V solar panel. i have to charge a 6V internal battery. then from there to a mobile........... could any one help me by giving a circuit diagram

THANK YOU FRIEND

2. ### mik3 Senior Member

Feb 4, 2008
4,846
63
You need to use a boost DC to DC converter to step up the 3V to 6V as to be able to charge the battery. Search in google for it.

3. ### SgtWookie Expert

Jul 17, 2007
22,182
1,728
This sounds like a homework assignment. Is it?

Trying to charge a 6v battery from a 3v solar cell will be very inefficient. For every 1mA charging current, you'll need roughly 3mA from the 3v supply, even if you have a very efficient circuit.

4. ### Wendy Moderator

Mar 24, 2008
20,764
2,534
Seems to me it would be more efficient to get a solar panel that produced something like 15VDC, and plug it into the cigarette lighter.

5. ### SgtWookie Expert

Jul 17, 2007
22,182
1,728
Since when do 6v batteries have cigarette lighters?

6. ### Wendy Moderator

Mar 24, 2008
20,764
2,534
Opps, skeed reading pills.

7. ### italo New Member

Nov 20, 2005
205
1
I sugest that you add 2 more panels to get to 9v. solar panels are specified as voltage and current output. you know one find the other specification. at 3v volts looks like you need 2 but 6 volts batteries are not 6 volts like 12v battery are not 12v more like 13.68v to be exact. so two would probably never fully charge the battery. 3 will. adding circuitry to make >6v will be ineficient except if the 3 v solar has quite of power output. which i ruther think not.