Here's why:
* Steady charging: A healthy car battery should charge steadily, with the meter gradually moving towards the "full" mark. The movement might be subtle but should be consistent in one direction.
* Fluctuations could indicate problems: If the meter is bouncing back and forth, it could signal issues with the charging system, like a bad alternator, faulty wiring, or a weak battery itself.
However, there are some nuances:
* Initial surge: When you first connect the charger, you might see a brief spike in the meter as the battery initially accepts charge. This is normal and should subside quickly.
* Battery type: Some advanced batteries (like AGM or lithium-ion) might have slightly different charging characteristics. These might show more nuanced meter behavior but shouldn't fluctuate wildly.
Bottom line: If your car battery meter is jumping around while charging, it's best to consult a mechanic to diagnose the problem.
