Can a 12 volt battery reverse polarity?

Can a 12 volt battery reverse polarity, yes, a 12 volt battery can reverse polarity in certain conditions, though normal 12 volt battery like car lead acid battery has fixed polarity with positive and negative terminals marked, but reverse polarity can occur if battery is connected backwards, charged backwards, or deeply discharged and recharged incorrectly. In lead acid battery, if you connect charger with reversed polarity, you can reverse charge battery causing polarity to reverse, though this damages battery. Also if battery is completely discharged to zero volts and then charged with reverse polarity, it can take reverse charge and actually reverse its polarity, with positive becoming negative, which is bad and damages battery. In some cases, 12 volt battery can appear reversed if you measure with multimeter backwards, but actual battery polarity reversal requires incorrect charging. So can 12 volt battery reverse polarity, yes, it can if charged with reversed polarity or connected backwards, causing battery to be reverse charged, which damages battery and can cause it to have reversed voltage, though modern batteries have protection, and deep discharge can cause cell reversal in multi cell battery where one cell reverses, reducing voltage, with reverse polarity being abnormal condition that indicates battery damage and should be replaced, as correctly charged 12 volt battery should maintain original polarity.