24v or 12v inverter & bank??

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  • Blackcherry04
    Blackcherry04 Solar Expert Posts: 2,490 ✭✭✭
    #62
    Re: 24v or 12v inverter & bank??

    You have to love being a retailer, I bought this Air Conditioner and it's the wrong size for my uninsulated Cabin, I want to return it, cause I am unhappy. Sounds like one of my customers.
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  • Dill
    Dill Solar Expert Posts: 170 ✭✭
    #63
    Re: 24v or 12v inverter & bank??
    Blackcherry04 wrote: »
    You have to love being a retailer, I bought this Air Conditioner and it's the wrong size for my uninsulated Cabin, I want to return it, cause I am unhappy. Sounds like one of my customers.

    well, I didn't mention the fact the water drain doesn't work, and the fan then blows water all over the inside of the thing, but that wasn't the point of the discussion either...
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  • Blackcherry04
    Blackcherry04 Solar Expert Posts: 2,490 ✭✭✭
    #64
    Re: 24v or 12v inverter & bank??
    Dill wrote: »
    well, I didn't mention the fact the water drain doesn't work, and the fan then blows water all over the inside of the thing, but that wasn't the point of the discussion either...
    Window units do not HAVE a water drain any longer the evaporator coil water is picked up by the fan blade slinger throws it on the condensing coil and it evaporates it ( it's called efficiency ). If you want a water drain you have to drill a hole and install some kind of a port and hook a hose . If you run a A/C in a uninsulated space you'll overload it a air that will be loaded with humidity, you'll have a over abundance of water and some Air Conditioners will freeze up.

    Your words, not mine "I might end up having to keep the AC anyways, I can't find the receipt! "
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  • Dill
    Dill Solar Expert Posts: 170 ✭✭
    #65
    Re: 24v or 12v inverter & bank??

    of course those are my words, you're acting like I'm trying to recant them or something? I just didn't think an air conditioner should spray water all over the window and outside wall it's installed in.

    Anyways, sorry to the OP for the diversion of topic.
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  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #66
    Re: 24v or 12v inverter & bank??

    Guys; play nicely. We've enough work to do just keeping the spam out, okay?
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  • Blackcherry04
    Blackcherry04 Solar Expert Posts: 2,490 ✭✭✭
    #67
    Re: 24v or 12v inverter & bank??
    Dill wrote: »
    of course those are my words, you're acting like I'm trying to recant them or something? I just didn't think an air conditioner should spray water all over the window and outside wall it's installed in.

    Anyways, sorry to the OP for the diversion of topic.
    In case you missed the point: once the space is Insulated and the A/C has removed the Humidity it won't be making all the water you see now.
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  • Dill
    Dill Solar Expert Posts: 170 ✭✭
    #68
    Re: 24v or 12v inverter & bank??

    thanks. I'll report back after installing insulation this weekend.
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  • ywhic
    ywhic Solar Expert Posts: 621 ✭✭
    #69
    Re: 24v or 12v inverter & bank??

    The good news (for me) is that the shipment of incoming panels is due in 6/25 and not the rumored 6/20.

    The other + note is the guy that gave me the $100 cash yesterday.. wrote me a check for the balance of $125 for 3 weeks from now..

    :cool:

    I may double pad/insulate the rear (South facing) wall to help keep that summer 100' F temp outside as much as I can..

    I plan on sticking a battery box OUTSIDE.. but debating on whether it should be on the same back wall or the left wall (away from the road view)..

    Any suggestions on a simple box to hold say upto 6 batteries.. would a Suncast Deck Box work for that.?? its 46" w x 23 1/2" d x 25.5" h and about $90..

    I would put/make a vent in the side(s) to let the air get thru it.. and of course a remote battery temp sensor..
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  • vtmaps
    vtmaps Solar Expert Posts: 3,741 ✭✭✭✭
    #70
    Re: 24v or 12v inverter & bank??
    ywhic wrote: »
    I plan on sticking a battery box OUTSIDE.. but debating on whether it should be on the same back wall or the left wall (away from the road view)..

    Any suggestions on a simple box to hold say upto 6 batteries.. would a Suncast Deck Box work for that.?? its 46" w x 23 1/2" d x 25.5" h and about $90...

    Why not put it indoors where it will be less subject to extreme temperatures? It will really appreciate the air conditioning in the summer.

    You can build your own box from plywood for much less than $90.

    --vtMaps
    4 X 235watt Samsung, Midnite ePanel, Outback VFX3524 FM60 & mate, 4 Interstate L16, trimetric, Honda eu2000i
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  • ywhic
    ywhic Solar Expert Posts: 621 ✭✭
    #71
    Re: 24v or 12v inverter & bank??

    I'm was thinking of the fumes being in a 12 x 24 building.. that will be slept in eventually.. (granted we will be UP in the loft)..

    Should I just build a BOX inside near the back wall and just mount the 'equipment' above it.. and leave the BOX available to get-at and vent the BOX to the outside with some PVC or ducting and small 4" vent with screening??

    I figured I'd ask the experts that have done this already?
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  • Vic
    Vic Solar Expert Posts: 3,208 ✭✭✭✭
    #72
    Re: 24v or 12v inverter & bank??

    Al,

    I have been wondering about your batteries, and just what you would do to keep the heat from the batteries. I had been hoping that they would be inside, and perhaps have PRIORITY for the A/C.

    During the heat of the day, you will most likely be in Asorb for a couple of hours ... or even longer. This is when the batteries are heated most during a charge cycle.

    Do not know your over-night low temps during Summer, but your outdoor batts will run above the average ambient temps, due to the heat generated during recharge (primarily during last half of Asorb).

    In my system, the Power Room has priority for A/C -- first on and last off (compared to residence A/C).

    Just my opinions. Have Fun, Vic
    Off Grid - Two systems -- 4 SW+ 5548 Inverters, Surrette 4KS25 1280 AH X2@48V, 11.1 KW STC PV, 4X MidNite Classic 150 w/ WBjrs, Beta KID on S-530s, MX-60s, MN Bkrs/Boxes.  25 KVA Polyphase Kubota diesel,  Honda Eu6500isa,  Eu3000is-es, Eu2000,  Eu1000 gensets.  Thanks Wind-Sun for this great Forum.
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  • ywhic
    ywhic Solar Expert Posts: 621 ✭✭
    #73
    Re: 24v or 12v inverter & bank??

    I found this on a website as a sample DIY box idea..

    Attachment not found.

    Keep the bottom elevated and then DUCT it out.. maybe a little 12v computer fan on the outbound duct..

    Heres one I just found on YT..

    Attachment not found.

    I hear you.. the good news is the prior planned A/C unit will be in the rear of the building also..

    Which the room will be 10' x 12'.. so the A/C should help the batteries a little bit..
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  • vtmaps
    vtmaps Solar Expert Posts: 3,741 ✭✭✭✭
    #74
    Re: 24v or 12v inverter & bank??
    ywhic wrote: »
    Should I just build a BOX inside near the back wall and just mount the 'equipment' above it..

    FWIW, it is a violation of code to mount your equipment above a battery box. I'm not sure what the rationale is for that requirement.
    --vtMaps
    4 X 235watt Samsung, Midnite ePanel, Outback VFX3524 FM60 & mate, 4 Interstate L16, trimetric, Honda eu2000i
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  • BB.
    BB. Super Moderators, Administrators Posts: 33,613 admin
    #75
    Re: 24v or 12v inverter & bank??

    May be a bit late--Can you dig a "battery basement" under your floor (or beside the cabin)?. Can be a good idea to keep the bank at ~70F vs the hot weather (may be an issue if you have seasonal flooding). Usually you only have to go down 1.5 to 3 feet for pretty stable soil temperatures.

    Between battery banks/wiring, generator, and fuel storage--Keep an eye on fire prevention/resistance (I have mixed opinions about batteries inside a living structure). Wiring to code (with breakers/fuses, metal boxes), using fire resistant materials (sheet rock, etc.) vs the common choice to hang equipment on a sheet of plywood, etc. all help.

    Do I do what I preach at my home--Not always. :blush:

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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  • ywhic
    ywhic Solar Expert Posts: 621 ✭✭
    #76
    Re: 24v or 12v inverter & bank??
    vtmaps wrote: »
    FWIW, it is a violation of code to mount your equipment above a battery box. I'm not sure what the rationale is for that requirement.
    --vtMaps

    Then the 2000 YT people whom have there equipment directly above the battery bank must be in violation.. LoL..

    Can the equipment be ABOVE the batteries if the batteries are enclosed and then vented AWAY??

    Thats what I meant by ABOVE the bank..

    Or would building or using a box outside that is insulated with styrofoam a better solution??

    BB.. Digging 3 ft into my ROCK ground is not likely.. if I was here in PA doing this then yes for sure..

    Temporary for about 1 week will be the plywood mount sooo many use.. then I will be rocking and such all the walls..
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  • Vic
    Vic Solar Expert Posts: 3,208 ✭✭✭✭
    #77
    Re: 24v or 12v inverter & bank??

    BB Bill's Root Cellar is a great approach to help moderate the temps for batteries.
    Beside the cabin could be fine, especially if it is mostly shaded during the heat of the day (which may be difficult).

    The venting should be screened with metal screen (for rodent and insect protection).

    There are so many tradeoffs in finding a location for batts, and containing their possible fumes, insulating but ventilating etc.

    None of my systems have seemed to be the ideal. Have thought of a Mini-Split indoor unit INSIDE an insulated, vented batt box.

    Vic
    Off Grid - Two systems -- 4 SW+ 5548 Inverters, Surrette 4KS25 1280 AH X2@48V, 11.1 KW STC PV, 4X MidNite Classic 150 w/ WBjrs, Beta KID on S-530s, MX-60s, MN Bkrs/Boxes.  25 KVA Polyphase Kubota diesel,  Honda Eu6500isa,  Eu3000is-es, Eu2000,  Eu1000 gensets.  Thanks Wind-Sun for this great Forum.
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  • ywhic
    ywhic Solar Expert Posts: 621 ✭✭
    #78
    Re: 24v or 12v inverter & bank??
    ywhic wrote: »
    with some PVC or ducting and small 4" vent with screening??

    Maybe inside with a good sealed box with venting to the outside would be a good solution.. if its vented with a small 12v fan I would think I would be ok and not have a sore throat everyday..
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  • Photowhit
    Photowhit Solar Expert Posts: 6,006 ✭✭✭✭✭
    #79
    Re: 24v or 12v inverter & bank??

    If you can't go down, build a berm shelter with a couple feet of earth around the batteries! may solve seasonal flooding problems.
    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Magnum MS4024, Prosine 1800(now backup) and Exeltech 1100(former backup...lol), 660 ah 24v Forklift battery(now 10 years old). Off grid for 20 years (if I include 8 months on a bicycle).
    - Assorted other systems, pieces and to many panels in the closet to not do more projects.
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  • ywhic
    ywhic Solar Expert Posts: 621 ✭✭
    #80
    Re: 24v or 12v inverter & bank??

    Back on the 12/24 inverter and bank OP question..

    So if I can scrounge up 2 12v 130 AH batteries and series them i'd be at 130 AH in the 24v configuration.. (and ok start to run my drill and such).. and everything that would be say 30 amps out of a 12v system would be about 15 amps of 'draw' from the same size 'bank'..

    I decided to go for panel #6 and be at 870 watts of PV.. and double to a 24v system using my Morningstar TS-45 (PWM) controller..

    I decided to go for the Samlex SA-1500-24 which has in its book a bunch of OK numbers..

    <= 1.5W in power saving mode
    87% Eff Rated
    1500 continuous
    1700 for up to 3 minutes
    2000 Surge
    GFCI Outlet (we've beat that subject to death)
    130 Amp Fusing Needed (better than my 250 amp)
    4 AWG wire (I'll be running 2 AWG anyway..)
    Unit says to just shove the wire into the terminal hole.. and it will handle upto 2 AWG.. :cool:

    Question.. I have this 3/0 wire already here.. can I do 3/0 from the Bluesea switch to the bank.. 2 AWG from the switch to the inverter.. and 2 AWG around the actual bank jumpers and be OK??

    I'll have 2 AWG on the bank (to make the series) and 2 AWG into the inverter from the switch.. (which said 4 AWG would be fine).. I just want to use the 3/0 for something..

    The other Question.. since I am running a PWM controller and seems like with a 12v system I'm getting 112 w/panel (77%)..
    with a 24V system and putting in 18VMP*2 = 36 VMP.. my settings for the bank would be at 28.8 Absorb (flooded).. I'm guessing I'm still losing that same 3.6 volts per panel.. correct?? and be at 672 Watts (112w*6).. (loosing 198 watts)

    or would I be a little higher at 691.2 watts (28.8 battery setting * [3 series*2] *8 IMP) (loosing 178.8 watts)..

    I'm thinking the higher 691 (which wouldn't hurt me mentally as much..LoL..)

    Short of selling the 2 week old TS-45 (PWM) and getting the TS-45 (MPPT).. I think I've done the best I could with what I got..
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  • Wxboy
    Wxboy Solar Expert Posts: 70 ✭✭✭✭
    #81
    Re: 24v or 12v inverter & bank??

    This thread prompted me to try to start my window AC units with my Xantrex SW 2000 but it wouldn't start either of them(nothing else was running on the inverter at the time). One is an older 5k btu unit and the other is a much newer 9.8k btu unit.

    I tried the 5k unit first(which draws about 500+ watts when running) and the inverter gave me an E04 warning and beeped and made all kinds of fan noises that I've never heard before). That's an overheat code but I would have thought it would have given an overload code.

    The larger AC unit would run the fan and then tried to start the compressor every few minutes. It would start and attempt so quickly that nothing really happened. No code on the inverter but the compressor wouldn't start. I didn't really expect that one to start but I figured I would try it anyway.

    So hopefully your new inverter will start your AC unit.

    I have a small battery bank but I don't think that came in to play because everything happened so fast I never saw the voltage drop. I guess it is possible though. I'm using 2 awg wire(4 feet), 12 volt bank at 136 ah total and 160+ watts of solar coming in at the time of testing.
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  • Dill
    Dill Solar Expert Posts: 170 ✭✭
    #82
    Re: 24v or 12v inverter & bank??

    that's pretty odd, I've started my 5000 btu on my SW 1000 before. I have a 440ah GC 12 volt bank.
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  • ywhic
    ywhic Solar Expert Posts: 621 ✭✭
    #83
    Re: 24v or 12v inverter & bank??
    Wxboy wrote: »
    I'm using 2 awg wire(4 feet), 12 volt bank at 136 ah total and 160+ watts of solar coming in at the time of testing.

    I think the 2 AWG for a 12V system drawing 50-60 amps thru it might be the issue..

    I was going to go with 3/0 'welding' type wire.. and my run was going to be only 45" overall.

    HD sells up to 2/0 & 3/0 wire at my local store as well.. maybe that and some of those compression terminal lugs for $4.49/2 might make a difference..

    What size wire Dill??
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  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #84
    Re: 24v or 12v inverter & bank??

    500 Watts on 12 Volts is 42 Amps. Plus the inverter draw. 2 AWG will handle it running providing the length is not long (no more than 6 feet) and everything else is "perfect". The start-up draw is still probably enough to fault the inverter (they react faster to over-current or V-drop than anything else will).

    That's the whole problem with heavy loads on 12 Volt systems: you need perfect battery (capacity and SOC), perfect wiring (big enough to virtually eliminated V-drop under load), and perfect connections between. Anything out of spec even slightly adds up to a significant extra resistance that causes it to fail.

    When you switch up to a 24 Volt system all the current issues are cut in half, which is a huge margin for error!
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  • Dill
    Dill Solar Expert Posts: 170 ✭✭
    #85
    Re: 24v or 12v inverter & bank??
    ywhic wrote: »
    I think the 2 AWG for a 12V system drawing 50-60 amps thru it might be the issue..

    What size wire Dill??

    15 inches of 2 gauge.
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  • Caneman
    Caneman Solar Expert Posts: 71 ✭✭✭✭
    #86
    Re: 24v or 12v inverter & bank??
    BB. wrote: »
    May be a bit late--Can you dig a "battery basement" under your floor (or beside the cabin)?. Can be a good idea to keep the bank at ~70F vs the hot weather (may be an issue if you have seasonal flooding). Usually you only have to go down 1.5 to 3 feet for pretty stable soil temperatures.-Bill

    BB, that is what I ended up doing... I had to dig out a battery basin inside my "solar shack" underneath the plywood floor... the other day is was 108F outside, 110F inside the shack, and 81F in the battery basin... I think Wayne from CA gave me this idea and it has worked out really well for my situation...
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  • ywhic
    ywhic Solar Expert Posts: 621 ✭✭
    #87
    Re: 24v or 12v inverter & bank??

    So I am guessing Cariboocoot that you are saying I will have better luck using a 24V system and inverter to get my planned 5K A/C on..

    Do you think a 1500 watt 24V Samlex inverter (rated at 1700 for 3 minutes) and 2000 watt surge will work?? :confused::cry:

    If the Xantrex 1800 Prosine can run most of this stuff I would guesstimate a 1700W rated should be able to also..

    The $485 for the SA-1500-24 is ok.. but the $800 for the SA-2000-124 not so much.. :cry:
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  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #88
    Re: 24v or 12v inverter & bank??
    ywhic wrote: »
    So I am guessing Cariboocoot that you are saying I will have better luck using a 24V system and inverter to get my planned 5K A/C on..

    Let's say it makes the chances of success distinctly higher.
    Do you think a 1500 watt 24V Samlex inverter (rated at 1700 for 3 minutes) and 2000 watt surge will work?? :confused::cry:

    If the Xantrex 1800 Prosine can run most of this stuff I would guesstimate a 1700W rated should be able to also..

    Don't bet on it. From Robert's test in the Fedders thread we see an A/C unit pulling nearly 3kW momentarily. The Prosine 1800 has a 2900 Watt surge rating. That's well above 1700!
    The $485 for the SA-1500-24 is ok.. but the $800 for the SA-2000-124 not so much.. :cry:

    This is always the dilemma; but if you don't spend the money on the equipment that will do the job you are wasting the money. Or as I sometimes say, "spend the money once or spend the money twice".
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  • ywhic
    ywhic Solar Expert Posts: 621 ✭✭
    #89
    Re: 24v or 12v inverter & bank??

    Looks like the SA-1500 is out..

    The SA-2000K-124 is in.. though the pricing is about $740..

    The SA-2000K has 92% eff and same 0.3 Amp in powersave draw (settable for 40-280w) .. 2000 watt continuos and 4000 watt surge.. and hardwire type.. and GFCI on front..

    The PST-200S-124 has only a 85% eff and <0.8 Amp draw.. 2000 watt continuos and 4000 watt surge.. its $640 ish.. GFCI inside.. :cry:

    This stinks.. IMHO..
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  • silvertop
    silvertop Solar Expert Posts: 155 ✭✭✭✭✭
    #90
    Re: 24v or 12v inverter & bank??

    I tried a while back to run my Samsung window A/C with my Cotek 1500 24V, I wasn't sure of the BTU; I couldn't find it on the unit but recently I did it, and it is a 10,200 BTU. I now can understand why it didn't start this unit! I don't think I would gamble on the Samlex/Cotek 2000 to run this. I hate the tare losses but if it were me and it will be soon ,I'm going to go with the Cotek 3000 24V. I will use this for the larger loads ( in search mode or on demand) to cover all bases, and use the Cotek 1500 24V to run 24-7. The one problem I have is running the refrigerator 24-7. I cannot use the inverter in search mode, it won't recognize and start it this way. Keep this in mind; these low tare losses in serch are mute if you need an appliance on continuous. also if you have the ability to put some loads on a timer for peak sun you will reduce your drain on your bank. I will be adding a 110V heat pump water heater this fall 660W that I plan to run at peak sun to minimize night time battery drain, I have several electrical loads that I do this with that only come on at 11:30 and run to 3 or 4 ( one is our water bed heater) It works great!8).......But if you can go 24V min.
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  • ywhic
    ywhic Solar Expert Posts: 621 ✭✭
    #91
    Re: 24v or 12v inverter & bank??
    silvertop wrote: »
    I tried a while back to run my Samsung window A/C with my Cotek 1500 24V, I wasn't sure of the BTU; I couldn't find it on the unit but recently I did it, and it is a 10,200 BTU. I now can understand why it didn't start this unit! I don't think I would gamble on the Samlex/Cotek 2000 to run this. I hate the tare losses but if it were me and it will be soon ,I'm going to go with the Cotek 3000 24V. I will use this for the larger loads ( in search mode or on demand) to cover all bases, and use the Cotek 1500 24V to run 24-7. The one problem I have is running the refrigerator 24-7. I cannot use the inverter in search mode, it won't recognize and start it this way. Keep this in mind; these low tare losses in serch are mute if you need an appliance on continuous. also if you have the ability to put some loads on a timer for peak sun you will reduce your drain on your bank. I will be adding a 110V heat pump water heater this fall 660W that I plan to run at peak sun to minimize night time battery drain, I have several electrical loads that I do this with that only come on at 11:30 and run to 3 or 4 ( one is our water bed heater) It works great!8).......But if you can go 24V min.

    Really.. can't you set the search mode down to like 40 watts on the Cotek models.. the SA-2000K has dip switches right on the front...

    I would think a refrigerator would be more then 40 watts though even just sitting..

    As far as the A/C.. heck yeah 10K+ is huge for a 1500 Inverter.. I'm only going to be shooting for a 5-6K unit and only during peak times.. The K models are supposedly rated for heavier loads..

    Of course by the time I get the $750 together they'll have something else out or discontinue that knowing my luck..

    I hope the MFG's stop getting rid of the smaller RV type stuff.. its messes us little guys up..

    My other option was a Xantrex TR (Trace) series.. though the 2424 model I want is like $865.. and I'm not sure of how clean the TR series MSW 'looks' to run some stuff like an A/C or Refrig.. maybe the TR 1524-24 would suffice as it has a 10 secondd 3K surge capability.. its cheaper at $735..
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