[qcj]

Went up this morning to check water in my batteries as I do once a month.  I always check the inverter panel and the inverter was charging and said batteries were good and 13.8 volts.  It is an Outback inverter.  Open up the door that has 4 of the six 8-Ds in it and the top two was hot and when I took the caps off they were boiling. I did not smell any sulfur. The other four were cool and not boiling.  I don't recall ever seeing this before but do usually check the water when they are charging.  My volt meter read 12.8 on each battery.  I did not disconnect the cables to check the voltage and there is no corrosion.   Soon after, I looked at the inverter panel again and it had stopped charging and said the batteries were in good condition and was 12.6 volts. The batteries are 4 years old and in the 3 and half years I've owned the coach they have never run dry.  Should I be concerned.