why does solar not fully supply load and draw 50% from battery?

Victron 100/70, 1000W renology panels, 3000W AIMS inverter, 620 Ah lithium batteries on truck camper. When battery full (or nearly full) and in float mode and AC is on, the 55 amps needed to run AC is not provided by solar - instead its about a 50% battery/ 50% solar split. I want to run AC on solar during daytime and conserve battery for nightime use.

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jacobjned commented · Jun 27, 2023 at 09:50 AM

A quick one, kindly confirm, that you mean Victron MPPT 150/70? Can you please share a screenshot of the settings you have used.
If I work on, 55A x 12V = 660W, does your MPPT via the VictronConnect app show that '300Wish' as PV generation?

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wmb jacobjned commented · Jun 27, 2023 at 11:42 PM

Yes mppt 150/70 (sorry). Pic of settings below. I use a trimetric monitor to track amps in and out. Thats how I learned that mppt was not supplying full load from PV. To expand, when load is increased from 55amps (AC draw) to 100amps (microwave) PV system will bump up wattage to the amount that provides about 50% of the load, with the rest coming from battery. So I know when AC runs with draw of 55 amps and the battery is providing 25amps and PV 30 amps, that more PV amps are available. Switching to the microwave 50amps comes from PV while 50 come from battery. IMG_6822.PNG

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img-6822.png (241.5 KiB)

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kevgermany ♦♦ commented · Jun 27, 2023 at 10:29 AM

Once the MPPT goes into float, it will stay there until battery voltage drops. With lithium, this can take a while due to the flat discharge curve.

There's a rebulk offset setting in the MPPT. Battery voltage needs to drop below float by this amount before the MPPT comes out of float. Try reducing this. You may need to tweak it a few times. You may wish to increase float voltage as well, but stay within battery maker's recommendation

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