How To Tell If Car Battery Is Fully Charged. Whether Im sitting at 100 kmh 60 mph or idling is irrelevant because the battery needs to. A hydrometer measures the specific gravity of a fluid.
Most common batteries have a specific gravity of 1265. Allow it to sit on float for a good day or two. When you trace the amp needle is dropped to half of your desired set amp it means the battery is fully charged and ready to set in the car again.
This is showing that the battery is fully charged.
Attach the 12-volt car headlamp to the positive and negative - terminals of the battery. Charge it up use a proper 3 stage charger and choose a low charging current. If you dont have a multimeter to tell you the voltage of your battery you can do a test of your electrical system by starting the. For 20 minutes then check again.
