wat inverter should i get for my solar set up?

wat would be a safe inverter(watts) to get? i hav four 6v 225ah trojan bateries wit two 100w panels charging them. i got a 4000w inverter rite now wich is killin my batereis. sorry im new to this. im jus guessin getin another inverter would b the anser? im thinkin 1000w or lower. is 1000w safe?

4 Answers

  • 10 months ago
    Favourite answer

    Hey Rebel, what's killing your batteries isn't your inverter, it's what you have plugged into it.  If you ran the inverter and didn't turn anything on the batteries would be fine, but what good is that.  200 watts of total solar is barely enough to run some LED lights and charge a couple cell phones.  We have that setup here, 200 watts solar, 2 6 volt 225 AH batteries for 12 volts, some LED strips in the kitchen, den and bedroom and cell phone USB outlets, all running on 12 volts DC, no inverter.  Still, our array can just keep up with the loads most weeks.  If you're running a refrigerator, or TV, or power tools, the 200 watts of solar isn't ever going to be enough.

    Is the 4000 watt inverter a Schneider Electric?  They are fine units, quite efficient.  Most models of that class are around 96% efficient under normal loads, so if your home is using 400 watts, maybe for the fridge and TV, the inverter is taking 416 watts from the battery to make the 400 watts for the house, it doesn't get much better than that.  By purchasing a smaller inverter, you might squeeze that 416 watts down to 410, but the house is still using 400, and a 200 watt array won't cut it very long, considering it can't do you any good at night or if it's overcast.  If you can trade in the inverter for a smaller one and not spend anything, or get some cash back, that's fine, but it won't fix your problem of too small an array.  Maybe spend the extra cash on more panels.

    Our cabin has a Schneider 4000 watt inverter, it's been running continuously for 17 years.  We have a medium size fridge, small 5 cubic foot deep freeze, one TV, stereo and all our lighting.  It all barely works on a 1400 watt solar array and a 900 watt wind turbine.  In fact, we have to buy in a few kwh's of power every month, usually a dollar or two, to make up for shortages.

    If you just want the 200 watt array for a few lights, skip the inverter entirely and go 12 volt LED.  Keep the inverter you have for emergencies if it's already paid for, and I'd consider using the money you were going to spend on another inverter to get more panels.  Solar panels all get along fine as long as the voltage is close for wiring in parallel.  If you're going in series for a high voltage array, then you need the same size panels to wire in series.  We started with a 50 watt panel on our DC system years ago, and later added more panel, it all works fine, as long as you don't go over the max amp rating on the charge controller.  Add up all the Imax amp ratings on the panels you have, and others you might add, that's the minimum size controller you need.  Good luck with it, don't give up, your system is pretty close if you already have those new batteries and the big inverter. Rudydoo

  • 10 months ago

    RTFM... ok, I'll just assume (if not, you'll have to do your own research) that you're using the Trojan deep cycle solar batteries, Solar SAGM 06 220. Their datasheet doesn't specifically state a maximum discharge current, but the discharge diagram stops at 25 Amps, which is close to the 10 hour discharge listed in the table, so I'll assume that.

    6V at 25A is 150 Watts. As you stated you have 4 batteries, that's a total of 600 Watts. The size of the inverter is pretty much irrelevant, but you can't (shouldn't) draw more than 600 Watts from those 4 batteries. If you can't ensure that on the consumer side, then yes, an inverter limited to 600 Watts will ensure you don't draw more than 600 Watts from the batteries.

    If you're using another type of battery, then you'll need to look up the datasheet for that battery and check the maximum permissible discharge current. A MOTIVE T105-AGM, for example, is rated for 75 Amps, which would let you draw 1800 Watts from a set of four (not that I would recommend these batteries for a solar installation, that was just an example).

  • khalil
    Lv 7
    10 months ago

    how much is your load?

    i assume 3kw .... for efficiency 80%, we need 3.75 kw so from a 24v battery the current will be 156.25 a .... that will kill the battery

  • Anonymous
    10 months ago

    you are trying to get 4000w out of 200 w fro

    m the panels and your batteries are charging at near 40 amps while the inverter will pull near 700 amps at 120 volts the batteries can last about an hour so basically you need 20 solar panels

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