Power Supply help

Hello, I am looking to build a power supply that can supply at least between 15,000 and 30,000 mAh at about 7V

I have considered wiring a group of double A batteries in both series and parallel but have determined that I would need atleast 25 batteries to achieve this…

As my project has space constraints I am wondering if anyone has an opinion of a different setup/ battery type or has some insight for me.

My project is consuming about 160 mA and I would like to have the battery last at the very least three days but was hoping for between 4 and 5!

It is an arduino uno with a GPS shield, I have seen GPS systems in retail that have batteries that last weeks and have a very compact design.

How is it that this is achieved? How can I achieve even three days without having so many batteries?

Any help will be appreciated!

Consider a 7.4V LiPo battery with 20-30mAh capacity. This will be about as small as you can get it. Unfortunately we don’t offer anything quite that large, but we may be able to do a special order if you contact us via the RobotShop Support Center.