“Do I remove the black wire or the red wire first?” 
Is this a thought that goes through your head? Do you feel like disconnecting your motorcycle or scooter battery is on par with defusing a bomb? Then you’ll be relieved to hear that It isn’t – but there are a few things you must know to stay safe.   In this blog post, you’ll discover:
  • 3 everyday situations where you need to disconnect your battery
  • Which cable you should disconnect first, and which one you should reconnect first
  • 2 final checks you must carry out once you’ve reconnected the battery

Prefer to get this information in podcast form? Listen to the 30 Minute Motorcycling Podcast episode about how to disconnect a motorcycle battery:

3 Common Scenarios when you need to disconnect your battery

1. When you’re replacing an old battery

Simple enough – if you need to replace your battery, the old one has to come out. And if the old one has to come out, it must be disconnected.

2. When you’re cleaning the battery terminals

Corroded battery terminals are a significant cause of a poor flow of electricity – therefore, if your terminals are corroded or dirty, you must clean them. Of course, there shouldn’t be any electricity going through the battery while you’re cleaning the terminals. For this reason, you must ALWAYS disconnect your battery if you’re cleaning the terminals.

3. Before replacing an electrical component

But even if the battery itself is in good condition, you still need to disconnect it for some tasks. For example, if you need to replace a headlight bulb, you don’t want to risk having electricity flow through the circuits. And the best way to prevent this is – you guessed it, to disconnect your battery.

Safety First – Remember Your Safety Gloves and Goggles!

Because of the risk of electric shock and that lead-acid batteries contain sulphuric acid (which is highly toxic), make a habit of always wearing safety goggles and gloves when working with batteries. This will minimize the risk of getting shocked – but also from getting sulphuric acid into your eyes. Finally, as a safety precaution, turn off the ignition completely before touching the battery.

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    How to Safely Disconnect a Motorcycle or Scooter Battery

    Before we even touch anything, let’s look at the battery itself.
    image of motorcycle battery

    On a motorcycle, you’ll typically find the below the seat. On a scooter, the battery sits underneath a panel covered by the floorboards.

    Either way, once you’ve removed the seat or the battery panel, you’ll see that the battery has two separate wires connected to it – one black and one red:

    • The black cable connects to the negative terminal – marked by a “-” character next to it
    • The red cable connects to the positive terminal – marked by a “+” character next to it

    And to prevent sparks from flying everywhere, there’s a specific order in which you should disconnect the cables.

    To safely connect the battery, you must first disconnect the cable leading to the negative terminal.

    This will break the circuit – meaning that no electricity can flow from the battery to the battery terminal connectors. 

    Also, if you can, try to keep your fingers away from the metal parts of the cable connectors and the battery terminals as much as possible. 

    Once the connector for the negative terminal is disconnected (and safely away from the terminal), you can disconnect the red cable for the positive terminal.

    There you go – you’ve disconnected the battery!

    How to Connect a Motorcycle or Scooter Battery

    So you’re done working on either your battery or your electrics. All that remains now is to connect the battery back.

    And just like disconnecting the battery, there’s a specific order in which you must reconnect the battery again.

    It’s essentially the same order in which you disconnected your battery – except in reverse.

    So to reconnect the battery, you must first connect the red cable to the positive terminal. 

    Once the red cable is connected, you can connect the black one to the negative terminal.

    You might see a few sparks when you do this, but you should be fine if your hands are away from the terminal.

    All Done? Carry Out These 2 Final Battery Checks

    1. Is the correct cable connected to its correct terminals?

    The black cable must go to the negative terminal, and the red cable must go to the positive terminal.

    Suppose you connected the wrong cable to the wrong terminal (i.e. the red cable to the negative terminal and vice versa). In that case, it could cause irreversible damage to your battery once you turn on the ignition.

    Remember to check next to the battery terminals for a “+” and a “-” to determine the positive and negative terminal, respectively.

    2. Are the connectors tightened down?

    Considering how much motorcycles and scooters vibrate, if you’ve got one or two loose connections to the battery terminals, your electrics might not receive the amount of electricity they require.

    This can cause them causing them to run sluggishly or not at all.

    Therefore, to ensure a stable flow of electricity, fasten down the connectors to the terminals on the battery.