Watchdog Sump Pump

I'm trying to solve an issue with this backup sump pump.
The original battery had one cell cap that allowed a probe to sense low fluid.
The first replacement battery, several years ago, was a deep cycle battery and the probe was clamped onto the ground (+) post. It worked well until recently and we bought another deep cycle battery and connected it the same way. For some reason, it sets off the alarm of low battery every day.
I have checked the voltage of the battery while disconnected from the charger. I have checked the charger for output and it reads 16 volts on my Fluke multimeter. I have cleaned the connections twice and made sure that they are tight.
Other than buying a new system, I'm lost. Anyone else have this type system? Problem?

Follow Ups:

• Re: Watchdog Sump Pump (url) - Bruce(OR) 13:50:08 10/01/23 (1)
  • Re: Watchdog Sump Pump - John in Mixh 14:03:49 10/01/23 (0)

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