Sentry charger surging

My 32v sentry charger occasionally surges, meaning it will come on for a few seconds, shut off, and repeat several times. I can "reset" the unit by flipping the breaker for awhile and it seems to correct itself. I have tried to pinpoint whether there is a certain electrical source that would trigger the action, but have fallen short. I have checked the batteries and they all have sufficient fluid levels. Search results haven't reflected anyone experiencing these symptoms. One other concern is my power bill is climbing month to month will no AC use anymore leading me to believe the charger may have something to do with it.

On my last boat I had a 32 volt system (two banks of 32 volts) with a sentry charger.
I started to experience the same thing (not the increase power bill but the charger cycling).
My battery water levels were fine but it turned out I had one bad (going bad) battery.
Found the bad battery buy using a high end battery tester. It turned out that it was one battery about to fail and was getting a high resistance connection internal between a set of plates.

I also had the same symptom once (Charger Cycling) and had a very difficult time tracking the problem down. Turned out to be a 32 volt light in the forward bilge left on.

Tim
Know Pressure
1979 53' MY

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Originally Posted by KPTIM

On my last boat I had a 32 volt system (two banks of 32 volts) with a sentry charger.
I started to experience the same thing (not the increase power bill but the charger cycling).
My battery water levels were fine but it turned out I had one bad (going bad) battery.
Found the bad battery buy using a high end battery tester. It turned out that it was one battery about to fail and was getting a high resistance connection internal between a set of plates.

I also had the same symptom once (Charger Cycling) and had a very difficult time tracking the problem down. Turned out to be a 32 volt light in the forward bilge left on.

Tim
Know Pressure
1979 53' MY

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Thanks Tim,I'll give those a check

Dead cell in there somewhere.

Is it normal for this type of charger to cycle when DC is being used? For instance if lights are on should the charger be cycling nonstop?

The Sentry charger will cycle if even a small DC load is being used. This is normal how the Sentry charger works it is on or off unlike an analog charger. When the Sentry charger is charging the internal fan is on and when it is not charging (at any level) the fan is off.