You definitely need to locate all of your batteries on the setup you have. You should have your truck start battery and in another location you will have your 'coach' battery. Sometimes this may under the steps.
This is probably the battery giving you the problem.
Like said above reading across the coach battery terminals you should read 12.6-7VDC if it is fully charged. When you connect up to shore power or generator this DC VOLTAGE should jump up to 13.6VDC or what ever mode your on-board converter/charger unit is doing. If you do not see these DC VOLTAGE changes on the 'COACH' battery terminals it may be some sort of BATTERY DISCONNECT switch may be engaged...
It takes more hours then you think to charge up a deep cycle battery.
This is what PROGRESSIVE Dynamics states in their operating manual on how long it takes to charge a battery using the DC VOLTAGEs listed below: "Progressive Dynamics ran this test on the amount of time it took a PD9155 (55-amp) converter/charger set to three different output voltages to recharge a 125 AH (Amp Hour) battery after it was fully discharged to 10.5-volts.
14.4-VOLTS (Boost Mode) – Returned the battery to 90% of full charge in approximately 3-hours. The battery reached full charge in approximately 11 hours.
13.6-VOLTS (Normal Mode) – Required 40-hours to return the battery to 90% of full charge and 78-hours to reach full charge.
13.2-VOLTS (Storage Mode) – Required 60-hours to return the battery to 90% of full charge and 100-hours to reach full charge."
This is based on having 17-20AMPS DC current available for each battery in your battery bank... NOTE That Progressive Dynamics doesn't even list using DC Charge Voltages around the 12.0VC range as this would take alot more than 100 hours to achieve a 90% or 100% charge state.
Based on your camper age it is doubtful you have a modern smart mode converter/charger on-board and what you have for a a charger is most likley a 13.6 charging setup. so based on this it may required 40-hours to return the battery to 90% of full charge and 78-hours to reach full charge. Pretty long time HUH...
If your battery has not been fully charged in a long time it is probably easy to say your coach battery is history now... Once you find it check the battery fluids and try to get a charge going on it alone... If you camper has sitting around for a few years I would count on replacing the 'coach' battery setup...
You have inherited a perfect sized camper... Would love to have one of those haha
Roy Ken
