Power input to batteries from gen

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Power input to batteries from gen

Postby DanOnly on Mon Jan 08, 2018 1:11 pm


I have a MATE3s and 2 GS8048A inverters with 3kW of solar and a 5.5kW LPG generator as backup (the generator is severely undersized but that's due to spacing) with a 1400Ah battery bank for storage

I'm strictly using the system as an off-grid power house and not selling back to the grid. The system works more than well enough when there is full sun, but on cloudy days or long periods of no sun the generator is needed.

My question is when I'm looking on Optics and I see that the generator output 27kW of power, and there was only 8.8kW of load, why is my kW to my battery so low? And is there a way to bump this up ? Another example would be that within an hour of 3 kw being produced from the generator, only 0.37 kw go to my battery (see attachment)

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Re: Power input to batteries from gen

Postby Mike Curran on Tue Jan 09, 2018 2:55 pm

Here's how I would interpret your Optics graphic: Solar + From Grid + From Battery should = To Load + To Battery

Plugging in your data, this equation becomes: [3.2 + 21.2 + 18.39] should = [33.3 + 3.72]

OR, 42.79 = 37.02. That's not too far off and I'd suggest it can be explained by inaccuracy in the "To Load" measurement, where I suspect any reactive power in your load(s) isn't being accounted for.. :-k

As far as power to your battery, are they getting an absorb cycle while your generator is running? Remember your inverters will cut back on battery charging to support your loads if loads approach your inverters' throughput limit. And if your generator is truly undersized your inverters will always be favoring your loads over battery charging. Maybe try charging batteries when loads are minimal?

Btw, you say your genny is 5.5Kw but your example gives 27kw as output :?:
Mike Curran
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