Need help with Inverter/Charger, Generator and Battery Bank set up for my off the grid treehouse...

tomwalla

Hi. I have an off the grid treehouse. I do not have solar because of the heavy tree canopy. Currently, I power the treehouse with the use of a 3400 watt generator with remote start. Works really nicely. However, I am adding a battery bank and a inverter/charger to minimize the use of the generator. I have purchased an AIMS 4000 watt pure sine inverter/charger. The inverter has a built in charger and transfer switch. The battery bank I have should produce 750 amp hours of output. My dilemma is this...The wiring diagram from the manufacturer of the inverter/charger shows the generator connected directly to the main service panel, (or to a transfer switch if there are other sources of ac power), then through the main service panel to the ac input side of the inverter/charger. The ac output side of the inverter/charger then connects to a sub panel. I am hoping that I don't have to put in a sub panel to be run from the AC output of the inverter/charger. I would like the same exact receptacles, lights, etc. that are powered through my main service panel to be either powered by the generator or by the inverter. What I would like to do is connect the generator directly into the AC input side of the inverter. The AC output side of the inverter would connect directly to the main service panel in the treehouse.  Is this possible??

mike95490

Can you post a scan of the section of your manual ??
Are you running 12V or 24V ?
750 ah out from a lead acid battery implies you have a 1,500 ah battery bank.  Only 50% of a lead acid battery is usable, only 70% of a Li battery is usable (the other 30% in Li is a safety margin at empty and full to avid fatal cell damage)

tomwalla

Sure, here is the basic wiring diagram for the inverter provided by the manufacturer. (Sorry, it is just a screenshot).  I am running 12 volts into the inverter. (6) 6 volt lead acid batteries. 

BB.

A 4 kWatt AC inverter is very difficult to get wired up correctly for a 12 volt battery bank... Current wise:

• 4,000 Watts * 1/0.85 AC inverter eff * 1/10.5 volt battery cutoff = 448 Amps max continuous input (and can be up to 2x that for surge current)

A 750 AH @ 12 volt FLA flooded cell lead acid battery bank can reliably support around:

• 750 AH * 250 Watts * 1/100 AH = 1,875 Watt maximum suggested AC inverter/DC loads

And--Just as a rule of thumb, about 1,800 Watt AC inverter @ 12 volts is pretty much the maximum suggested inverter (for 12 volt battery bank).

Wiring up a 448 Amp bus with a maximum of ~0.5 volt drop (typical max suggested for a 12 volt battery system) is difficult... You need a lot of very heavy copper wiring with the cable lengths to be kept short.

Wiring up two electric panels can work... An AC panel that connects to the genset--And a second panel that connects smaller loads to the AC inverter (as needed).

-Bill

mike95490

I'm going to let Bill work this for you, I have little usable advice other than transition to a 48V system and get away from the toys

wellbuilt

Yes you are off grid so you could just hook the genarator to ac in and hook your panel to ac out. 

 The inverter should charge and feed your loads when running and invert power to your loads when the genarator is off. 

   The amis  equipment gets a bad rap on the site , 4000 watts is large for a 12 volt system . 

  The inverter is going to be a huge load on your battery’s before you turn anything on. 

 I run a 2800 sf house with a 3600/ 48 volt system  I use 200/300 watts day time 150 to 200 watts night time . 

  Bigger is not better , size your inverter to your loads . 

 I use out back equipment  its very sweet . 

  I tried skimping on equipment on a small system and it worked for a couple of years till it killed my battery’s .

  I would step up to a 48 volt system just add 2 more battery’s . 

   Mike and bill give great advice . 

mike95490

The inverter is likely only 120VAC and would only energize One of the Two AC buss bars in the sub panel. 

wellbuilt

It would have to be a really fancy tree house to use 240volt power . 

 I only have 120 volt power so I ran a jumper in the panel to energize both sides .