Low Batt alarm

[jeffprupis]

Good morning. Been on 50amp shore power for two weeks. Headed out this morning, disconnect from power and Low Batt alarm goes off. Batteries full of DW, been floating at 13.5-8v for 2 weeks, currently at 12.6v. Amber Low Batt light still lit on SCP. SOC 100% Any thoughts?

[Fred Brooks]

    Hey Jeff, How old are the batteries, what kind, and when were they serviced last? Things are a little deceptive when you are plugged into shore power. The 12volt from the converter powers up the interior support, then a 3 stage charger brings the batteries up to float charge. Need more info before we move forward. Fred

[David T. Richelderfer]

12.6v does not indicate low batteries.  When off shore power and without the generator, fully charged 12v batteries should show 12.6v to 12.7v.  But your coach has two banks of batteries.  What is the charge status of the other bank of batteries?  Do you know which bank of batteries is showing 12.6v?

[jeffprupis]

The batteries are at least 3.5 years old (I had them installed 6/16). 4 X Interstate GC2 6v flooded. They are maintained monthly. The system control panel reads the house batteries (I believe).

[Fred Brooks]

    Jeff, as Dave states 12.6 is not that low. 12.7 is the accepted standard of a fully charged 12 volt deep-cycle flooded battery that has stabilized after sitting for a day. Just to check, I would disconnect each battery and check voltage (6.3or 4) and perform a hydrometer test, should be 1275 and above. This is to make sure there is not a bad cell starting to fail. 1 bad cell will affect the battery bank. Fred