Battery Meter Displays C (charging)

[Michael & Sue]

When I press the BATTERY button on the Water Tank/Battery Meter, it always shows all 4 lights lit, indicating the battery is charging. This happens even when we are not plugged in to a power source, not connected to the tow vehicle, and having run on battery power for a couple of days. Any suggestions about this?

 

[SethB]

Do you use any significantly power-hungry appliances, like a fridge, furnace, or the television? The cabin/galley lights, and water pump don’t draw much. Not sure about the fantastic fan.

In my experience 4 lights indicates near full or full charge, in addition to charging. Is it possible that you’ve not drawn down the battery enough to get down to 3 lights?

How old is your battery, and have you (or former owners) been diligent in keeping it on shore power when stored?

If you’re using the heavy appliances and the indicator stays at 4 lights that could be a problem... to diagnose, you’d measure the battery voltage when you think it should be discharged. Turn off all loads, *not* charging. If your battery is above 12.5v (or close) that 4th light may be correct.

Camp Inn includes a plug-in meter, which can be very helpful!

 

[Michael & Sue]

We don’t use any power-hungry appliances, and we tend to use the fan sparingly. Our teardrop is a 2019, and we leave it plugged in during storage. Based on what you’ve said, I’m going to bet that we simply haven’t used enough power to drop it down to 3 lights. I had assumed that it would drop to 3 lights (good) as soon as it was not actually charging. Perhaps I’ll try an experiment and run some appliances while at home to see what happens! Thanks for your response!

 

[Tom Sutor]

The battery meter with the 4 lights is based on voltage. Voltage is not an accurate way to measure state of charge unless it is open circuit voltage, which is the voltage when the battery has equilibrated after being at rest for several hours. I think 8-24 hours is usually recommended. If you use or charge a battery the voltage changes and cannot be used to measure state of charge. The graph below shows state of charge versus OCV. The volt meter in your camper by the main switch can give you OCV if you check it first thing in the morning before using any powered devices such as water pump or lights.