On a boat, I found a Multi 24/2500/70. The red LED for Battery Low lights up. The batteries are ok. 26.4v and in good condition. Certainly, has done some service for a few years. Turn on shore power and turn it "on" first green "Main", then additionally yellow for bulk and then it switches to Battery Low. All connections and fuses ok and correct. When shore power is off, the inverter works flawlessly. My question too; should not one replace with a newer model which is also ve bus capable?