Assuming that you have, or can get, a set of jumper cables when you find that your motorcycle battery is dead, getting the bike started is no big deal. But you can cause harm if you do it wrong.

Connecting batteries in series is what you do when you pop a couple of cells into your flashlight. That is, you put the positive terminal of one battery into contact with the negative terminal of another. The result is that the voltage provided is the sum of the voltages of both batteries. This is NOT THE WAY to connect motorcycle batteries!!!

When you connect batteries in parallel, by placing the positive terminal of one into contact with the positive terminal of the other and the same with the negative terminals, then the voltage that results remains the same, but the amount of current that can be produced is raised. You need current to power your starter.

Always be sure that the batteries you will be connecting together are of the same voltage.

Always connect the same polarity terminals together when jumping a battery.


If you connect the opposite polarity terminals together your battery can EXPLODE!

Always wear eye protection when jumping a battery!


Batteries can explode from another cause as well: a charging battery creates hydrogen gas.

Make sure the vent tube on your battery is connected properly.

Make sure you are in a well ventilated environment - preferably outside.

Do NOT SMOKE while charging or jumping a battery.


Lay out your jumper cable so that the connectors are not touching each other. Then, connect the positive (red) lead of the cable closest to your dead battery to the positive terminal on that battery followed by connecting the negative lead (black) to your negative battery terminal. Be sure that these connections are firm - wiggle them a little in order to let the teeth (if any) on the jumper leads cut into the terminal metal posts.

Always start by making the connections on your dead battery.


Why? Because you cannot kill a dead battery! (If the loose ends of the jumper cable were to touch each other.)

(It might be better if you connected the negative lead to some part of your bike frame rather than to the negative battery terminal in order to keep any potential sparks away from generated hydrogen gas. However, there cannot be a spark from a dead battery, connecting the leads to the dead battery does not yet create a circuit, and in the next step you will take pains to avoid a spark with the live battery.)

Next, connect the positive (red) lead of the other end of the jumper cable to the functional battery's positive terminal. Again, wiggle the connection to encourage a good 'bite' of metal to metal. [If you are unable to gain access to the battery terminals on the donor vehicle, (many are very inconveniently located), you can connect the positive jumper lead to the starter solenoid lead closest to the battery.]

Finally, connect the remaining (black) lead to some part of the frame of the donor vehicle. Since the negative terminal of all modern vehicles have their negative battery terminal connected to the frame of the vehicle (called a 'ground'), this is the same as connecting to the negative terminal of the battery. However, since this last connection establishes a live circuit, it is possible for there to be a spark when the connection is made. You want any spark that might occur to be as far away from the battery as is reasonably possible.

Though MOST vehicles today use a negative ground, you must check to be sure that is the case before you connect the jumper cables to the donor battery. You can still use it even if that vehicle uses a positive ground, but you must remember to connect positive to positive and negative to negative.


Generally speaking, it does not matter if the vehicle engine is running or not when you do this. The battery will be producing the proper voltage an