Timed Arduino, Solar Panel, Battery & 12V Pump HELP

Hi all,

I'm a struggling to do a project in less than 1 week for a charity and wondering if the www can help. I'm a complete electronics/Arduino beginner so please break any suggestions down, thanks!

The challenge:
I need a little water pump to run for 3 seconds with a 10 minute pause completely off the grid 24/7 from a battery. I need the battery to be charged using a solar panel and hold enough storage to run 2 days without sunlight. An Arduino is also needed to change the duration and interval of the pump.

What I know:

The pump requires ~12v @ ~270mA (5W)
and 64.8mAH (for 2 days of operation)
(pump runs for 18s per hour = 0.05h per hour
0.05h x 270mA = 1.35mAH
1.35 x 48hrs = 64.8mAH)

I also need to be able to take the battery on a flight so please recommend a suitable battery for the system (I was thinking maybe the Li-ion 18650? link).

Pump: link

What is the simplest way to wire & code everything up? (Please also recommend any required components)
Any help is much appreciated!

Use 8-10xAA NiMH cells to provide ~12V, not a lithium battery.

The cells can by charged by a 12V solar panel suitable for car battery topping, like this one.

Google "Arduino DC motor control" for lots of tutorials.

It is too bad you waited so long to start this project.