I need to create a small circuit that runs a 12/24vdc diagram pump, attached pump curve. I want to run this circuit from say a 24v drill battery if possible. I have read up on some battery circuits but need some help and insight about building the circuit. I need a run time of 3-4hr min, says .3A max draw, so i calculated roughly 1.5AH battery.

I know you shouldnt discharge the battery below 20%. What is the best/easiest way to control this, is there something i can just wire inline or would the drill batterys have it integrated if i buy a certain model?

I also want to integrate the charger and be able to power the pump from 120vac as well. I can buy a 120vac to 24vdc power supply and have a switch to switch between 120vac or 24vdc battery source.

Would a 24vdc battery backup be a better choice for this circuit, since it would probably have everything already integrated?

 

Off the top of my head, a scooter battery, controller, and charger would do most of what you want.

Scooters often use two SLA batteries, have low battery shut down, and have automatic battery charger.

 

Most of what you want can be had off the shelf, and I'd recommend that. Get a 24V battery charger meant for the chemistry of the battery you plan to use. If it's rated for the combined current of the pump and the battery charging. For instance I imagine a 1A charger would do nicely.

But I'm not as sure you can find a low-battery cutoff. There have been a few threads in this forum on that topic. Look for "low voltage cut off" or similar terms.