A dead motorcycle battery can happen, and it’s not a hard problem to deal with either. When properly maintained a modern motorcycle battery is so reliable that we rarely even think about it. Because we don’t think about our battery too much, it’s important to forget the basics, like how to safely use jumper cables to jump start a motorcycle with a car. When you know what you’re doing, jump starting a motorcycle is easy, but if you aren’t sure what you’re doing it can lead to some very expensive and very dangerous outcomes, so please pay close attention.
Ideally, you’ll never have to use jumper cables on your motorcycle, especially with all of the new pocket-sized booster packs you can get for under $100, or the all-in-one jumper/tire-inflators you can get for a little bit more. If you’re reading this, you’re probably in a pickle right now and don’t have a booster pack, but you probably have some jumper cables and a car. Good news: You can totally do this yourself. In fact, it’s a job best done by one person. Here are some instructions on how you can jump-start your motorcycle with a car.
How to jump start a dead motorcycle battery
Can you jump start a dead motorcycle battery with a car? Yes, you can absolutely jump a motorcycle with a car, but be careful! A car is designed to put out a lot more power than a motorcycle is capable of handling. For that reason, you’ll want to follow these instructions carefully, and make sure you proceed with the car not running. If you don’t do so, you can completely fry your motorcycle’s electrical system, which can be very expensive to replace.
Step 1: Before you start connecting things, assign one person to do the work
The first step is the most vital, but a lot of people will get it wrong. Jump-starting a motorcycle from a car is a one-man job, so your first step is assigning who will be doing the work. It’s important to have one person staying on top of the connections of all four jumper clamps (two at the end of each cable) because a little miscommunication between parties can have some bad catastrophic consequences. Keep it simple, have one person to make all of the connections.
Step 2: Connect the red cables first
Once you’ve determined who’s going to be doing the work, it’s time to get started. You’ll be working with two vehicles, let’s say, a car with a charged up battery, and a motorcycle with a flat battery.
Start with the car not running, and obviously, your motorcycle won’t be running either.
Take the red jumper cable and connect it to the positive terminal on the motorcycle’s dead battery.
Then connect the other side of the red cable to the positive terminal on the car’s healthy battery.
Step 3: Connect the negative (ground) cables
Next up, you’ll connect the negative terminal of each battery.
One thing to note, is that regular car jumper cables are huge compared to the size of a motorcycle battery, so proceed with care. Because of the size of the clamps, it’s really easy to knock things around or create a short and see some sparks fly. A few sparks by themselves are no big deal. A few sparks if your vehicle also has a slow gas leak you haven’t noticed yet, KABOOM! Game over. You don’t want that.
If you don’t have enough room to get to the negative battery terminal on the motorcycle without potentially knocking off the clamp off of the positive battery terminal, just clamp your black cable to any non-painted metal surface on your bike.
The other end of the black cable should go to the negative terminal on your car healthy battery. Some cars might have specific places set up for clamping to if the battery is difficult to access. Look for a little picture under the hood.
Step 4: Double-check your connections
Cars aren’t cheap, and neither are motorcycles. Each vehicle is loaded with a lot of expensive and finicky electronics. Double-check the connections by giving a light careful tug on the clamps and making sure everything is wired up positive to positive, negative to negative. Stay clear of any obstructions or interference.
Step 5: Start the motorcycle
With the car turned off, start the motorcycle. Assuming your battery was the reason your bike wasn’t starting, and your car’s battery is healthy, your motorcycle should fire right up.
If your motorcycle does not fire up, do not start the car.
If you’re using another motorcycle to boost your motorcycle, start the motorcycle with the healthy battery first, then rev it up a bit to get the voltage up, and then start the motorcycle with the weak battery.
Now let the motorcycle that had a dead battery idle. Use as little power as possible (low beams, no extra lighting, etc.) for a few minutes. This is to test that the bike won’t die out at low RPMs and leave you stranded again.
Note: There is a big difference between cars and motorcycles. Cars have alternators. Motorcycles have generators or magnetos. Alternators do a better job of converting power at low RPM.
Running a motorcycle at idle will not charge your battery, nor will going for a short ride. Motorcycles need high revs for extended periods to recharge their batteries. Cars do not. That’s why you can recharge your car battery by idling, but you’ll have to ride a motorcycle at high RPMs to recharge it.
Bonus: The 2 smartest things you can do after giving your motorcycle a boost
After giving your motorcycle a boost the two smartest things you can do are recharging your battery, and testing your battery.
As previously mentioned, letting your bike idle won’t recharge the battery. A fast-paced ride will recharge your battery, but how long should that fast-paced ride be? 20 minutes, an hour, two hours? You don’t know, because it all depends on your battery’s overall health, your motorcycle’s overall condition, and most importantly, how you’re riding. But a battery charger made for motorcycles knows exactly when your battery is fully-charged. This one is only $25. Play it safe, play it smart, and plug in your battery to a battery tender made for motorcycles.
The next thing you should do is test your motorcycle’s battery. Motorcycle batteries can be brought back to life, but that doesn’t mean they won’t die again soon! You want to make sure that your battery is still healthy, will still last you for years to come, and won’t leave you stranded on the side of the road. Here are two ways to test your motorcycle battery and even the charging system on your motorcycle:
You might also be interested in this article on why you shouldn’t start your motorcycle over the winter to charge the battery. Hint: It doesn’t actually work, be sure to check out why.