Per title my question is rather simple, will it benefit me to add another battery?

I'm currently running Deye 12kW 3-phase Inverter, 6.37kW in PV and 2x Dyness 5.12kWh batteries. PV is unfortunately East/West facing with no opportunity to do any north.

Per my screenshots below I've improved at managing my usage and have my geysers down to basically an hour each in actual run time per 24 hours.

Currently my time of use lets the house run on battery from 8pm to 4am and discharge is set for 100% to 40% during that time. When the morning geyser kicks in it uses whatever is left.

The idea of adding an extra battery would essentially be to expand the above period to possibly go from 6pm to 5am as, generally, we don't have anything big that draws power in that period.

I'm unsure if this would improve my parabola though  Despite running the swimming pool and both geysers now during the morning I get back to 100% charge by 14:00.

@Arzy I'm in a similar situation. Let me point in another direction. 

Geyser heat pumps are way more efficient and cost around the price of a 5kwh battery. 

If you go with the heat pump you, you can heat your geyser even on cloudy days. With a 4kw element I usually have to wait for eskom to come back if it's cloudy. The morning slot would barely make a dent on your current battery if you had a geyser heat pump. 

You could sell back excess pv.

I'd start by first improving self-consumption, getting the consumption peaks below the generation curve. Start the pool pump an hour or 2 earlier, and don't run it at mid-day when the geysers are on. Consider discharging deeper to 30% first, before buying more batteries. Just my 2c.

Edited October 5, 20232 yr by GreenFields