I lived in a solar powered house for 20 years and used a regular ole Shurflo demand water pump, actually many pumps over the years. Sometimes the pump would run on or not start. The problem was usually the pressure switch on the front. Sometimes a piece of debris or a bug would get in there and hang the switch. There may be another problem with your pump causing it to run on before the switch shuts it down. You may have an air leak on the incoming side causing the switch not to reach pressure and shutting down. That pump should shut down a few seconds after any faucet or valve is closed.
You can get a VOM at NAPA, you'll want one that can read at least 10 amps. Your instructions will tell you how to set the meter up but basically you'll switch the meter to read amps, leave the black lead in the COM port and switch the red lead to the AMPs port. Those two leads will go in series with the negative battery cable and negative battery post. Disconnect the negative battery cable and place the red meter cable on the black battery cable. Place the black meter cable on the negative battery post.
The meter may show a small drain if you don't have a major draw. If you have a major draw the meter will show a full amperage draw. The amount I can't say but it will be significant.
If you have a major draw then you have to go searching to find the culprit. Perhaps a storage compartment light is draining the battery or a light that you don't know you have is on. Maybe it's the water pump too.
Also, I need to revise the amperage draw on the pump. Depending on how much GPM it's rated the pump can draw from 5 to 8 amps. That's a lot on a battery if it runs on for a long time.
2013 Voltage 3800, 2012 Chevy 3500 HD
2010 Yamaha V Star 950
2009 Yamaha Raider
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