Hi,
Could be several things.  Your problem could very well have been poor
connections at the battery terminals.  Some other things it could be.
You don't say what type of charging system you have or if you have an
inverter or converter.  Just about all the charging systems turn off
and on by sensing the battery state.   Or what size batteries you
have.  You should get a hydrometer and check the batteries to make
sure they are ok.  Also if you have a Xantex/Heart Interface
controller and inverter/charger make sure the controller it is on
charge when you run the generator that way the batteries will get a
full charge or at least be brought up to 85-90 percent.  If you have
just a converter it could be that causing the problem if it's one of
the older non electronic types.  They don't put out a very large
charging current.

To check your draw while boondocking you will need to get an amp
meter and install it so it can read the current being drawn from the
batteries.  An Amp meter with a shunt is what is usually used.  There
are clamp on meters too that just go around the wire but they are
pretty expensive.  A good multi meter will work for smaller loads.
You need to check the meter to see what the max Amp load is.  You have
to be careful because the batteries could easily put out more current
then the multi meter can handle.   If you are looking for small
parasitic loads the multi meter would work.

If you plan on doing a lot of boondocking larger sized batteries are
a good idea.  Two six volt golf cart batteries will give you around
220 amps.  Four wired series parallel would give you 440 amps.
If you don't have the room for the golf cart batteries then two Series
31 deep discharge 12V batteries will give you around 260 amps (Trojan)
Three would give you 390 amps.  The golf cart batteries are around $50
each.  The deep discharge 12V are probably close to double that,
though I haven't checked lately.

Take care and Happy Campin...
RichA
"We Get Too Soon Olde and Too Late Smart"

That is the LAST assumption I would make of original, "factory" batteries.  In
fact, I'll bet they're the smallest, cheapest batteries Newmar could find.

I wouldn't hold this "fact" (if true) against Newmar, however.  Most, if not
all, high-end motorhome manufacturers assume that most of their rigs will
NEVER rely solely on batteries.  Given that virtually all such motorhomes have
a generator and most buyers wouldn't be caught DEAD without an electric
hookup, the motorhome manufacturer provides JUST enough battery capacity to
operate the slides and jacks a couple of times without generator or shore
power assistance.

If you're serious about boondocking WITHOUT having to frequently run the
genset, you should replace the stock batteries with higher capacity ones.  The
OP made excellent suggestions as to quantity and type/size.

BTW - a little dashboard solar charger provides so little power as to be
almost useless.  Such devices are generally used to MAINTAIN a charge while
the rig is in storage.  It would take such a small solar panel a month of
Sundays to "bring up" a battery from a discharged state.

Good luck!
                :)
JR