tweaking bulk, absorb V, Classic 200, 1150W pv running mini split heat pump

[bigal]

Off on a  mad venture here to build the "motorhome of the future"   My betters think this a crazy venture, but Im having fun using my solar and HVAC skills to make a poorly designed box somewhat habitable.  Ive tossed out the noisy,energy hog rooftop AC unit.  The loud propane furnace is gone.  Old 60's technolgy ONAN Genererator deep -sixed to make room for outdoor half of Mini Split.
New components as follows:

Hot water(Hydronic) heating system using standard domestic hot water heater as a boiler- alittle slow but it works and is quiet(3 amp draw)
https://plus.google.com/photos/117217437979967014172/albums/6255788533504201153

4x 285 Solaworld on the roof.
Magnum MS2012 full sine wave inverter-with remote
Classic 200-remoted MNGP
2x115AH- 20 hr  12volt system.   Marine deep cycle, flooded batteries(yes I know could do better, but I have them and they are new, so will try it)

120V Inverter style mini split heat pump, 9000BTU. Installed in the coach pictures here:

https://plus.google.com/photos/117217437979967014172/albums/6264315715787778193

Mini split  is soft start, no spikes draws Max  about 700W Settles to 450- 500W on low cool,.

Ive tested  last 2 days, max  output so far 800W on the classic. (high clouds)      No real issues, but I need to configure the classic out of float to make more power at end of charging cycle, but with plenty of sun. The real use starts later in the day when ch. cycle done and in float.

Open to suggestions!!

[ClassicCrazy]

When your loads go on later in the day the Classic will supply all available power , and if  the load takes more than available and the voltage drops it will come out of float.

What else would you want to accomplish ?  If you wanted to you could use the Aux contact to turn a load on earlier when SOC gets to a certain point. That would work well if you had electric heating element in your hot water heater.

Larry

[Westbranch]

I'm not so sure I like that picture with the heavily bandaged fingers, better call a medic!... 

Numbers:  those batts will only supply ~1300W (or less) to 50% depletion... so you might get as much as 3 hours, just on batteries.....  just so you are aware. 

To really know, a Kill-a-Watt measurement is needed... say a sun up to sun down on a scorcher of a day, while on grid... using the settings you expect to use.  It will also let you compare the units output against expectations...

hth

[bigal]

Thanks for comments guys....

yeah, dont want to talk about the fingers- bad move, but  I cant stop -- got stuff to do- life is short!

Original plan was to just use sun for ac when it shines here in  sunny NM. We try not to camp in hottest weather - nothing short of an iceberg will keep a MH cool in 100+
More power  will likely  be needed late in day that sun cant supply. That 3 hrs out of batteries would be great if it will do that much.  They would go to bed discharged but would get fully charged before next cooling use I think. A Honda eu1000i genny would also supply enough for some extra hrs--but Id rather not.

Changed a couple settings today and cleaned panels good, ready for another test day tomorrow!!

[Westbranch]

well, using a rule of thumb, you will need at least 110% to fully recharge so if you pull 1300W out you will need ~1450W back in... if the inverter is 85% efficient, now you need ~1700W

you have 1140W of PV * 70% to cover losses in getting to the battery and out, so at max output you will get ~800W so now you need~2.1+ hrs of full sun...  +

next you need to factor in the tare consumption of that inverter.... eg if it uses another 30Watts per hour you need to add this to the total...

hth

[bigal]

Got remote control of inv. so can cut losses there. 
All led lites, no loads to speak of in mornings so it should charge in am.
  Last nite was 70%charged. Will   see how long takes today with weak sun.  Thanks for running the numbers- will see how well it follows in real life.

[TomW]

Dry heat.

Why not use a swamp cooler arrangement to cut the BTU load? I understand they run on much less power than Air Conditioning, pump some water, blow some air.

Oh, yeah, water is probably precious, too.

Up here in the Midwest it is the opposite, soggy and steamy hot. we mostly burn the electrons squeezing the water out of the air.

Just pre coffee rambling.

Tom

[bigal]

Thanks Tom,
swamp cooler def in the plans.  I was back east couple times and dont want to travel w/o access to AC at least!

How bout solar roasted coffee?  I got the only solar powered roaster  in NM in think. Fresh roasted Ethiopian right now....