Second inverter to same battery bank

I want to add a pure sine wave inverter to power a window unit and fridge in my house. Have a modified for some lights and a couple of receptacles. Just want to add to my current set up. Anything I need to know or do?

Comments

  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: Second inverter to same battery bank

    sure, of course there is.
    how about the total surge watts on startup for both of the inverters keeping in mind they can startup at the same time. this determines the inverter wattage rating and the battery bank. if it is high wattage then this could sway you to go with a higher voltage for the battery bank and inverter to cut losses and of course the charging source needs to supply the current to charge the battery bank at the proper voltage and current with at least 3 stages of charge. this is a general overview as the wiring, fuses, disconnects, etc. could be addressed.
  • System2
    System2 Posts: 6,290 admin
    Re: Second inverter to same battery bank

    Both together not even close to what is available from my system and I am careful not to overload system. Will be using separate disconnects for each. Each have their own purpose and nothing higher than I am using now.
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: Second inverter to same battery bank

    If each inverter has its own fuse or breaker and the total potential loads on both at once won't overwhelm the battery bank it will work fine. Many people do this, in fact.

    Just remember that a window AC and a refrigerator each have quite substantial start-up surges, which will not show up on a Kill-A-Watt meter. What Niel was pointing out was that these surges can cause a sudden drop in the battery Voltage and may fault the inverter if everything on the DC side isn't large enough to handle the demand. Particularly a problem with a 12 Volt system.
  • waynefromnscanada
    waynefromnscanada Solar Expert Posts: 3,009 ✭✭✭✭
    Re: Second inverter to same battery bank
    If each inverter has its own fuse or breaker and the total potential loads on both at once won't overwhelm the battery bank it will work fine. Many people do this, in fact..

    I'm one of those people. Actually have 5 inverters wired to the same battery bank, although only 3 are in regular use. One (PS 300) is on 24/7; a second is on only when fridge or freezer want to run; and the third, a Xantrex Prosine 1800W sits on standby 24/7 for heavy loads, band saw/skill saw water pump etc + a second freezer on an out building, and at times all three are on at once. The other two were in use a couple of years ago, and are left connected, but switched off with a DC disconnect, for backup if needed.
  • 2manytoyz
    2manytoyz Solar Expert Posts: 373 ✭✭✭
    Re: Second inverter to same battery bank

    I'm another one using multiple inverters. I initially did this to reduce the parasitic load caused by a large inverter running with no load most of the day.

    I use a MSW 400W inverter to periodically run my living room lighting. To switch on the lights, I use a remote that powers up the inverter. http://2manytoyz.com/gridless.html

    I'm also using a MSW 400W inverter to run the outdoor 120V CFL carriage lights on the outside of the garage. A Morningstar charge controller operates the inverter via a relay, turning on the lights from dusk to dawn every evening. http://2manytoyz.com/cflinverter.html

    A Xantrex Prosine 1800W sits on standby 24/7, with all my critical loads attached to it via automatic (single circuit) transfer switches (homemade). When the grid goes down, the loads are transferred to the inverter. The inverter powers up when a >20W load is applied. I also use this same inverter to operate tools in the garage, the washing machine, etc.

    Now that my solar array has finally grown to 900W, I can leave a PSW inverter running day/night, and live with the large parasitic load. That'll take some rewiring, so I'll continue to use multiple inverters for a while.

    Zero issues using multiple inverters in my case. I have a 900AH battery bank, and using buss bars to feed the system.
  • Fullpower
    Fullpower Solar Expert Posts: 69 ✭✭
    inverter to same battery bank

    Currently running a pair of 2500 watt inverters on my 24 volt bank, they are all getting along fine. The electrons seem to know instinctively where to find the load.