I'm in the process of selling our R179 (we bought a sailboat) and I just (20 minutes ago) put in two new 12V AGM deep-cycle batteries.

I have a cheap battery charge indicator the previous owner installed and it has always been fairly reliable.  I plugged the trailer back to AC and immediately the charge indicator is blinking and showing a charge level of 17 or 18 volts.  I immediately flipped off the 15A charge breaker.

My initial thought is the convertor (WFCO WF-9855P) has failed.  Is there anything else I should check before I get that replaced?  If I have it replaced should it be the same or is there a better choice?

Thanks,

Sean

Your 'indicator' may be indicating bulk or absorption charge and it might still be normal voltage at the battery terminals during charge, probably around 14 to 14.8 volts...in that range. 

Float or resting voltage should probably settle at around 12.9 to about 13.5...again...in or near that range.

After several hours or a day with minimal loads, your battery will probably settle around 12.5...give or take a few tenths either above or below that.

If you see those patterns, you can probably ignore the 'charge indicator'....

Of course you're right.  I went and checked with my voltmeter and it read 13.35.  Once I did that and rechecked inside the trailer of course the trailer meter read 13.5.

I'll try to save my calls for help for real issues in the future.