This is related to the question about digital chargers I posted last week.

 I was recently camped in the same spot for four days, running lights,
fans, sink, rechargers, stereo, etc. and finally ran the battery down
so low it wouldn't run the clock. So low that my digital charger did
not even sense that it was hooked to a battery. It failed to charge.
My friends sharing the site pulled out a big analog charger and
charged my battery right up. But they have a huge van they pull a boat
with, I don't want to carry a huge heavy charger if I can help it.

This gave me pause to think about what am I really going to
replace/supplement my charger with? I like the digital charger, and I
am often in state parks where there is electricity to charge with (but
not always). I like the lightweight, small digital charger. I am
wondering if I should get one of those 300 amp boosters they sell
everywhere, but will that just provide a measurable presence for my
digital charger, or will it actually run the glow plugs and crank my
diesel? If it would, I wouldn't mind going for one of those because it
would cover me even in the woods.

If a 300 amp charger won't do the job, what would be the minimum setup
to let the digital charger know there is a battery there to be
charged, and how must it be hooked into the system? I'm thinking of a
very small 12v battery, maybe two lantern 6v cells, to provide the
necessary capacity for the digital charger to sense.

What I really need to do is get my second battery and hella relay
re-installed but what to do till then? And, is there a reasonable way
of installing a smart charger so that the battery is continuously
being charged when shore power is plugged in?

Thanks,

Jim