A lead acid battery is essentially dead once it gets to 12 volts, and it is very bad to leave them there for any length of time. If this has been done over time in a 2010, then the battery may not be capable of holding a charge and you may need to replace it.
They typical operating range (unloaded and not charging) is 12.8 to 12.4 volts which is about 50% of capacity. If a battery is depleted past the 12.4 volt point and left there it will sulfate and lose capacity.
The typical converter in most campers will charge and hold a battery at 13.7 ish volts when it is fully charged and being charged and that voltage should drop back to 12.8 at rest.
I'm guessing that you need to consider replacing that battery and keep closer tabs on your voltage and charging to try to keep it between 12.4 and 12.8 volts whenever possible.
If you frequently use a generator to charge your battery, you may want to look into an external 3 stage charger that can charge quickly on the generator, which the camper's convertor may not be doing.
Just some ideas
2007 Chevy 2500HD Classic LBZ Duramax/Allison (Stock)
2005 Bigfoot 1500C8.2 AWESOME