Marine fridge not working when I disconnect from AC power

[Keir Penny]

I have a Beneteau 2006 373. It has a sea frost compressor that runs the fridge and separate freezer with the thermostat in the fridge unit. I had sent the compressor back to Seafrost last year and had them check it out. They said everything worked fine and put an updated control board on it. The fridge works fine when I am plugged in at the dock. When we leave the dock the fridge only works for a couple of hours and than shuts off as if there is not enough battery power even though the volt meter is still reading 12.5 volts. I have six golf cart batteries wired in a series and parallel. They are only two years old. What could be the cause of this happening? Is there a relay or something that could be burned out. Any help would be greatly appreciated.

[danno7]

Things are pointing to low voltage. When it works on the dock, the battery is kept at about 14 volts. Now you are reading the voltage at 12.5, which is normal. But, what is really important is what is the voltage right at the refrigerator when it is trying to start.

You have either got bad batteries or a bad connection from the battery to the refrig. Bad batteries can measure over 12 volts with no load on them. It can also be bad connections between the refrig and the battery. What you must do is measure the voltage at the refrig when it is trying to start. I will bet it is under 11 volts.

[boatpoker]

Originally Posted by danno7

Things are pointing to low voltage. When it works on the dock, the battery is kept at about 14 volts. Now you are reading the voltage at 12.5, which is normal. But, what is really important is what is the voltage right at the refrigerator when it is trying to start.

You have either got bad batteries or a bad connection from the battery to the refrig. Bad batteries can measure over 12 volts with no load on them. It can also be bad connections between the refrig and the battery. What you must do is measure the voltage at the refrig when it is trying to start. I will bet it is under 11 volts.

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