When a car battery is connected backward, a fuse designed to protect vehicle electronics should blow. If your vehicle doesnt have a fuse (almost all cars do) designed for this purpose, you will send electrical current backward through systems in your car, including ECU, transmission control unit, and more.

What happens if you put battery in backwards?

If you put in both batteries the wrong way and apply a negative voltage, your device may be damaged. The designers may not added a protection circuit (i.e. a diode) because its battery powered and they need all the voltage they can get. If a device causes a short, that can damage the batteries.

Can a 12v battery reverse polarity?

But Can a 12-volt Battery Reverse Its Polarity? Yes, it can happen. If the battery cells are out of balance, some cells will discharge before the others. As it continues to discharge, they will start to reverse polarity.

What happens when one battery is connected with reverse polarity in a series of batteries?

Connecting a Battery to the Charger with Reverse Polarity In short, It may partially or fully damage the charger circuit. It may discharge the battery with spark or permanently damage the battery.

What would cause a car battery to reverse polarity?

Reverse Polarity Battery Reverse polarity can occur when the terminals and the cables are incorrectly connected. When polarity is reversed the current is going in the wrong direction. During this situation, if anyone touches the device, it can cause electrical shocks or it can damage the device.

Can you reverse polarity on a battery?

Can Battery Reverse Polarity? You can also reverse the polarity of a battery after youve activated it. This is rare, but it is possible. So, the only way for a positive-charged battery to reverse itself is to discharge completely, and then reversed charged.