How To Tell A Positive And Negative On A Car Battery

For alkaline batteries, it is easier to tell and determine which one is the positive and the negative terminals. The one with a nipple is the positive sign, and the flat side is the negative side. One thing, most alkaline batteries bear the sign + and – to indicate which one is positive and negative.

However, in a car battery, the signs and symbols are not visible. It is dangerous to be guessing, which is positive or negative. Wrong polarity may result in severe damage and injury.

Do you know how to tell positive and negative on a car battery? Identifying the positive and negative side of a car battery is relatively easy. Look for the following signs or markings, and you will never go wrong with car battery polarities again.

1. Look for the + and – signs.
2. Check for the colored plastic covers and wirings.
3. Do a manual checking of your battery terminal size.
4. Use a voltmeter.

These four sure signs are ways on how to check and identify the polarity of your car battery. If some car batteries do not bear the sign or markings, remember the three other ways of testing a car battery polarity.

More Details on the Ways to Identify the Positive and Negative on a Car Battery

1. Look for the + and – signs. Most batteries bear the mark of the + (positive sign) and the – ( negative sign). These are one of the visual markings embossed on the battery so you could never go wrong on its polarity.
2. Check for the colored plastic covers and wirings. Looking for the colored plastic covers and wirings is another visual markings. The protective cover with the red color always represents the positive side. While the black cover carries the negative terminal side, the same color-coding goes for the battery wirings.
3. Do a manual checking of your battery terminal size. If none of these are visible on the batteries, you may check on the terminal size of the cell. The positive terminal is always more significant than the negative side.
4. Use a voltmeter. If all things failed, there is still hope. Use a voltmeter in looking for your battery’s polarity. The one with the highest voltage is always the positive side, and the lesser one is still the nominal voltage.

In What Order Should We Connect and Reconnect the Battery?

Extreme caution should be practiced when we connect and reconnect car batteries. Take this step by step process when you disconnect and reconnect batteries.

A. Find the battery

Try to locate the battery. It is the rectangular box located under the car hood. Latest models of cars have already provided a cover for their assault. Lift it and find the positive and negative terminals of the battery. If you can’t find your battery, use your car’s manual to find it.

B. Identify the positive and negative terminals of the battery

After finding the battery, the next thing is to determine which one is the positive and negative side of the cell. Some batteries bear the signs + and – symbols. Others would use a color-coded cover which has a red for the positive and blue for the negative terminal. This color-coding is the standard for all car batteries. In case they changed it, check your manual.

C. Detach the negative terminal first

It is an SOP or Standard Operational Procedure, always to disconnect the negative terminal first. An electrical shortage may happen if you removed the positive first. In removing the negative wire, try to loosen the battery connector and shake the terminal off to loosen up. Then remove the positive terminal. Do it the same way as you removed the negative terminal.

D. Reconnect the positive terminal first

After doing everything, you need to do with your battery. You can reconnect your cells with the positive terminal first. Remember, in detaching. We remove the positive last. In reconnecting, you put the positive terminal first. It is for the same reason for not creating a short circuit. Be careful not to touch any metal parts of the car, or it may spark.

E. Return the battery cover and close the hood

When you are done with everything, bring back the battery cover, and you may close the car hood. It should not create any problem if you have connected the battery correctly. If your car did not start, better check your battery from rust and dirt.

It can also be possible that your battery has shorted. It may go unnoticed, but your battery’s negative terminal must have touched a metal part of the car.

Why Do We Say that the Positive Side of the Battery is Hot?

Expert mechanics would use the term “hot” for the positive terminal of the battery. It is only connected to carloads like lights, radio, pumps, motors, and many more. And once you touched on those wires, it is alive and can ground you. It will create a spark that will fly and most likely to cause a fire if there is no fuse.

Will it be Safe to Touch the Positive Side of the Battery?

A 12V car battery is safe to touch. A car battery cannot electrocute you. More so, the positive side of the battery is safe to touch. Traditional cars and vehicles needed a lot of amperages to run well. Lead-acid batteries are better in providing short and intense amperage. However, a 12V battery doesn’t provide enough amperage to electrocute you.

How Can I Tell Which Side is Positive or Negative on My Car Battery if They are Unmarked?

If batteries are unmarked and you find it challenging to identify the positive and negative side, and there are no color-coded caps either. Then it is time for you to use the voltmeter. As I have mentioned in the beginning, there are four ways to identify the battery terminals.

Using a voltmeter is one if you can neither identify the polarity of the battery or there were no markings on the terminals itself. The terminal with the highest voltage reading is the positive side.

What Will Happen if You Interchanged the Battery’s Positive and Negative side?

Interchanging the connections of the battery terminals will only result in permanent damage to the battery. It will result in a big surge of electricity in the cell.

If you are jumpstarting a battery, the loss will extend to the other battery. The immediate reaction will be an overheating of batteries. Extreme heat can damage the internal and external parts of the cell.

Sources:
1. How to Tell Positive and Negative Terminals on a Car Battery – Auto Parts Warehouse
2. Disconnecting and Reconnecting Car Batteries – MCM Garage Bat