When does adding a 3rd Delta Pro Ultra battery actually make sense?
I had Delta Pro Ultra with 2 batteries (12kWh total). Works fine for 1-2 day outages if I'm careful with AC usage. But PSPS sometimes goes 3+ days. Wondering if I should add a 3rd battery now or just wait and see.
The math: Gets me to 18kWh which should cover 3 days pretty comfortably. Or do I just add portable solar panels instead and stretch the 12kWh by recharging during the day?
What did others do? Batteries first or solar first?