Can low DC voltage affect pressure switch operation?

[Zilpo55]

I discovered that our house batteries have lost some of their storage capacity on recent tie-outs away from dock. My rough estimate is that the batteries (about 3 years old) are about 70% of what they used to be. I don't want to replace them this late in the season, so I'm going to try to limp along using a new solar charging system I have on order plus use a spare battery as needed.

To add to this problem, our Shurflow fresh water pump will keep running when the house battery voltage decreases to a certain point. The runaway pump then drains the batteries even faster to the point that the CO detectors start beeping due to low voltage. The pump will turn off properly after I start the generator and DC voltage goes back up. Is this normal for a pressure switch, or is the switch failing also? Should I consider replacing the switch?

[midnight]

Best guess: Low voltage is degrading the performance of the pump to the point that it is not strong enough to build adequate pressure to trigger the switch.

[Zilpo55]

Best guess: Low voltage is degrading the performance of the pump to the point that it is not strong enough to build adequate pressure to trigger the switch.

That theory makes sense based on what I've observed so far. I'm going to try and monitor house voltage more closely on our next outing.