Depends. You may ruin the battery, or blow the fuse if equipped. More than likely will not hurt any other electronics but there is no guarantee.
You can't recharge it hooked up in reverse. You will destroy the battery or the charger if you try it.
Possibly, wrong polarity. Check whether you connect the battery correctly or you are using a correct battery.
Overheat he battery to the point of busting it.
you can blow fuses or the battery Possible computer damage.
Nothing as long as it was a 12 volt battery.
The proper polarity has to be adhered to so as to make the meter's needle deflection move in the correct direction. The wrong polarity will deflect the needle in the opposite direction and pin the needle against the needle stop on the left side of the meter's scale. This could un-calibrate the ammeter and the readings would not be accurate if this happens.
No, not the battery. But anything that has a diode, transistor or is in any other way dependent on polarity may be fried... including your alternator.
All batteries have two terminals, one positive and one negative, and usually they need to be hooked up right for the equipment to work. Some equipment will be damaged if you hook the battery up the wrong way - reverse polarity. Equipment that has reverse polarity protection has something in them which makes them able to stand being hooked up wrong w/o being damaged.
Electrolytic capacitors tend to explode when connected to AC or to DC currents of the wrong polarity. The plates short out because the dielectric is maintained by a polarized field, and is then destroyed by the wrong polarity.
charger i had was wired wrong. soon as it was plugged in the charger stopped working. if wires are wrong it just will not charge and can be dangerous!
"If you connected the battery in reverse that will certainly fry the alternator and cause damage to any other polarity sensitive components as well. The alternator is NOT suposed to spark, it charges by by generating alternating current which is converted to direct current through a diode pack known as the rectifier, and the voltage is regulated by some more electronic wizardry called (amazingly enough) a regulator. Normally when alternators go wrong the charging warning light will glow, and you will get the wrong readings from your voltmeter (if your car has one)."
All batteries have two terminals, one positive and one negative, and usually they need to be hooked up right for the equipment to work. Some equipment will be damaged if you hook the battery up the wrong way - reverse polarity. Equipment that has reverse polarity protection has something in them which makes them able to stand being hooked up wrong w/o being damaged.