Fluctuating and low power in my inside storage facility ?

I own a 2003 Country Coach Intrigue 42 ft bought new.  Been storing it in inside storage in Phoenix area.  In this storage building for over 6 years.  No problems thus far.  Yesterday went to visit the coach and noticed the coach electric was cycling on and off showing low voltage at the inside surge protector. So thinking maybe the surge protector was failing I called my RV tech who works lots at this place. 
Today it was not turning on and off with the low voltage light flashing worked fine the hour I was there.  The tech said they have voltage issues here because there is like 20 amps or so for several RVS inside and out on this circuit.
He said it is not a bad idea to turn OFF both coach and chassis kill switches off and figure out how long your coach batteries will hold up and then come back on regular intervals to recharge them.  Actually good on batteries to drain a bit and get recharged. 
Never noticed this problem before just wondering how others would approach this I know when I bought the coach years ago at the seminars they kept telling us keep them plugged in always. 
Cycling on and off every 2 or three minutes as it was yesterday seemed not good on my coach.  Must of been happening on others too my guess.  I am ordering a digital voltmeter to place in outlet but just thinking about next season what my options are ?  Is there something that would kill the power at the plug if under voltage and cycle back on at say a certain interval so the electrical system isn't constantly cycling on and off.  The Tech said i could do a test and kill both systems and come back in say 2 weeks see where my batteries are then try say 3 or 4 weeks until I figure out how long it takes for the phantom discharge to really effect things badly.  Would not want to let batteries go below say 8 volts. 
Curious to hear your thoughts on my options.

Thanks Gerald Brawley

I take mine out for the storage season as they would discharge and freeze. You probably dont have to worry about freezing but they will discharge if there is draw from some source. If you have both chassis and house disconnects, i would shut off both if you are not removing them. I generally store them for the winter in my heated garage. About mid season, I will pull them out when I have time. I check all the fluids and recharge them. They then go back on the shelf until spring when I give them a top up before going into the coach. If you dont want to remove them, it wouldnt hurt to recharge them as the mechanic suggested every once in a while to keep them from discharging too much. If the mh is stored where you can start the generator, run it for a few hours and turn on a few appliances so you can exercise the generator at the same time. 

8 Volts?? You would be buying new batteries very shortly afterwards as any battery allowed to go anywhere below 12.0 is very dead, and not likely to be recoverable. A fully charged battery reads about 12.6 Volts and a dead one about 12.0V.

In any case, if charging is involved, the water level in the battery cells has to be checked regularly, and topped up using distilled water if needed, especially on older batteries. Taking them out for care and trickle charging them at home is probably a good idea given the circumstances (unreliable power).

When dry camnping my batteries last 5 hours.. Much longer if disconnected.

Cycling on and off every 2-3 mintes.. Depending on your Energy Monitor System (Progressive Industries or TRC) and in the case of PI (Do not know about TRC) hard wired the settings.. Just shy of 3 minutes is the time-in timer.

If the voltage goes too LOW (or high) it will disconnect.. We will stick with low

SO the voltage goes low.. The unit drops you off-line  Now th evoltage increases (No load on your branch) so it times in )(3 mionutes) Well 172 seconds on a TRC I think 160 on a PI) then it re-connects.. The voltage soon drops as stuff inside draws power and it cuts you off again.

Problem suspects
Bad power plug (Corrosion on the blades) (your problem)
Bad power socket (Weak springs/corrosion on the contacts) (Facility problem)
Bad wire, bad connection to socket, or breaker, or at a junction box (Facility problem)
Bad wire (Shore cord to Surge Protector (your problem))

I think that about covers it.

Just wondering what my options are to protect the charging system batteries with the low voltage outlets.  The tech who works in the facility suggested disconnecting from outlet and checking how long it takes for batteries to go down.  Then coming back to facility to recharge, start up etc. 

I am wondering if there is anything out there that would kill the power at the plug in the event of low power and not just keep cycling my surge protector 24/7. 

Or is there something that would alert me in the event of low voltage at the outlet?  But no wifi in the building so doubtful on that? 

Or options I have not thought of we are gone many times for a month plus so not too handy to keep returning.

42 ft country coach intrigue 2003. motorhome.

What kind of converter do you have in the coach?  If it's a separate converter like the Progressive Dynamics with an AC plug on it, connect it to an extension cord and plug it directly into the shore power, bypassing the EMS.  Leave the rest of the coach unplugged and unpowered.

I've had the Progressive Dynamics 9100 series in a couple of RVs and they're rated for an AC voltage input anywhere from 105 - 135 volts and I've seen them work fine as low as 90 volts.

In other words, low voltage within reason won't hurt them.  If one should die, a replacement isn't that expensive.

not sure I will have to check that out thanks for your help and concern.