Battery Level Indicator

[moallen]

The only accurate way to check the charge level of a battery is to measure its specific gravity with a hydrometer. Hard to do with sealed batteries and seldom necessary.

Those monitor panels only read the voltage level of the battery, like using a voltmeter. Trying to see how charged a battery is with a voltmeter is difficult, because the difference is just a few tenths of a volt. A good fully charged battery is going to drop a little during load but then jump back up when the load is removed. Mine drops to 1/4 if I activate the breakaway (electric brakes) switch on battery power only.

These are resting voltages, i.e., 2 hours after charger/converter is disconnected.

12.66 = 100% charged
12.45 = 75% charged
12.24v = 50% charged
12.06v = 25% charged
11.89v = 0% charged

During charging, the voltage should be 13.8v to 14.4v, depending on temperature.

[jcarlilesiu]

On battery power, if I turn on the camper lights, the gauge shows only 3/4 full on a full charge. Turning off the lights, and it bounces back up to full.

Is this normal?