I made a watering cart for my garden last week.
The problem: drip watering to orchard trees that are 200 feet from the nearest spigot and random garden watering where dragging the hose to the plants takes longer than the actual watering.
I got this 16 gallon plastic tank from Northern Tool .
The whole rig. It's powered by a lawnmower battery.
I got this 12 volt pump from Amazon for $15. Made a filter from a piece of Koi pond filter. I cut a piece out of the lid of an old storage tote to mount it on.
The switch is in a plastic device box. I used a fish tank hose throttle to throttle the water flow down to 1 gallon every 4 minutes.
Zip tied the hose to stick to make it easy to place and heavy enough that it stays where I put it.