Post #9413

Imagine your battery is a fuel tank. But you can only be sure how much fuel is in it when it gets full. So each day when you fill it and see gas coming out the filler spout, you know it is full. Now you can never measure the depth of the liquid so you have a flow meter that tells you how many gallons or liters per hour are flowing out. You track this by subtracting each hour of usage from the full capacity of the tank. Thats a pretty good assumption but what if there's a leak in the tank you don't know about? What happens when your 25% assumed remaining fuel is suddenly missing? If you keep tabs on the flow meter you'll never know it. This is essentially what happened last night when one battery took itself off line. So what I did by telling the inverter to charge from grid when voltage is at 47v was the same as putting a float switch near the bottom of a fuel tank as a second method of checking the amount of fuel remaining.