Seeking help on decreasing voltage & current for personal project

[Steve]

All,
Please forgive me if this is in the wrong group.

I'm trying to make an external battery source for my Digital Camera
using mostly stuff I have laying around or can pickup locally here in
Missouri.

I own a Kodak ZD710 Digital Camera - I'm wanting to use a portable
external battery I bought from CompUSA when they closed the store in
my area several years ago.
The battery is "Initial RB-270 9V/5400 mAh" (http://www.initialdvd.com/
accessories.asp)
I used the battery a couple of days while travelling other than that
it's been in a drawer.

Looks like my Camera requires 3V / 2.5 Amps
I found this by looking up a compatible AC adapter on Ebay
http://cgi.ebay.com/ws/eBayISAPI.dl...ksid=p3907.m29&_trkparms=algo=LVI&its=I&otn=2



Question is there some component I can send the output of the battery
through to drop the voltage and current to where I need them. 3V / 2.5
Amps

My goal is to have a lightweight portable external battery that last
longer than the AA batteries.



Thanks
Steve

 

[Steve]

Thanks Paul,
I've spent the last couple of hours making a pack using 2 D cells.

How long should a full charged pack last?
Can you explain - why 2 D cells last longer than 2 AA cells - If both
produce 1.5 volts.
I'm not following

Thanks Again
Steve

 

[Steve]

Thanks Paul,
I've spent the last couple of hours making a pack using 2 D cells.

How long should a full charged pack last?
Can you explain - why 2 D cells last longer than 2 AA cells - If both
produce 1.5 volts.
I'm not following

Thanks Again
Steve








- Show quoted text -

Update:
I used 2 D cell batterys - I tested the output @ 3.24 volts
When I connect to camera nothing happens

Any suggestions

 

[ehsjr]

Thanks Paul,
I've spent the last couple of hours making a pack using 2 D cells.

How long should a full charged pack last?
Can you explain - why 2 D cells last longer than 2 AA cells - If both
produce 1.5 volts.

Think of them as similar to gas tanks for your car.
A larger tank contains more gas. With more gas, the
car can driver farther.

Batteries contain chemicals that react to produce the
voltage. If the AA and the D batteries are the same type,
then they contain the same chemicals. The D is bigger, so
it contains more of them, and therefore lasts longer.

Ed

 

[JosephKK]

Thanks Paul,
I've spent the last couple of hours making a pack using 2 D cells.

How long should a full charged pack last?
Can you explain - why 2 D cells last longer than 2 AA cells - If both
produce 1.5 volts.
I'm not following

Thanks Again
Steve

Really quite simple, the D size cell carries 4 to 5 times the energy
of an AA cell, thus should last 4 to 5 times as long.

 

[Jasen Betts]

Thanks Paul,
I've spent the last couple of hours making a pack using 2 D cells.

How long should a full charged pack last?
Can you explain - why 2 D cells last longer than 2 AA cells - If both
produce 1.5 volts.
I'm not following

same reson a 205l barrel of fuel lasts longer than a 20l jerry can