My above calculations were based on a 50% discharge to help prolong battery life. I wouldn't want to drain a battery further than that. Generally the inverter will manage it though, the smart ones shouldn't drain past 50% I believe. Draining a battery past a certain point speeds up the deterioration of the battery and will therefore shorter the lifespan - as well as leaving it discharged. I know with the lithium batteries, leaving it fully charged also puts extra strain on it and will reduce the batteries lifespan... This is why electronic devices such as phones are never sold with fully charged batteries. Sent from my Redmi Note 7 Pro using Tapatalk