How to Tell if Your Motorcycle Battery is Bad: 5 Signs

Whether by email, phone call, or chat, our Tech department answers questions nearly every day about the signs of bad motorcycle batteries. These queries often involve batteries that may be getting older and are failing to start their motorcycle, ATV, snowmobile, or side-by-side consistently. We thought it might be handy to list the top things that indicate a failing battery.

This list will hopefully be a guide and help you determine things like:

So, without further ado, here are the top signs that your motorcycle battery is ready for recycling:

1. Engine won't crank.

Consumers quite often wonder if a bad battery will still crank the engine. A bad battery will NOT crank a motorcycle engine. A battery needs to deliver enough power to the starter to quickly turn the engine over. When there is insufficient power, the engine will not turn over or will turn over too slowly to cause ignition. While this could certainly be a sign that the battery is discharged, it‘s definitely a sign that something needs to be done. Let the testing begin!

2. Battery self-discharges quickly.

You did the right thing and kept your motorcycle battery on a trickle charger. You disconnect the charger and fire up the bike. Yay! Everything is good so far. Then you realize you left your phone in the house, shut the bike off, and get your phone. When you go to restart your motorcycle, the engine won’t turn over. WTH? This is a sign that the battery has lost the ability to store charge and has gone bad. Grab your handy multi-meter, and the battery is likely reading a low voltage.

3. Battery has become swollen.

If your battery has become swollen, misshaped, or looks out of sorts, this is a sign that you might have a bad cell inside the battery. When you get a bad cell, the charging system tries to ‘make up’ for that missing voltage and can overheat the battery. Once that happens, there is no turning back. You have a bad battery, and it’s time to shop for a new one!

4. Battery shuts itself off.

While not the most common failure point, this can show a bad weld inside the battery. This would present itself in an inconsistent manner, such as sometimes working and sometimes not. Also, the battery might show good health on a meter until you put it under load, dropping voltage until the load is removed.

Be careful with this one, though! Often a bad connection somewhere on the battery cables or terminals can be the culprit. Best to check the battery voltage on the terminal directly rather than on the cable clamps. Much like the wack-a-moles in the old arcade games - hard to nail on the head; checking anywhere besides the terminals directly can be hit or miss!

5. Battery won’t take a charge.

If you use a smart charger that never goes ‘green’ on the charge status indicator lights, you could have a bad battery. One of the first things to check is your charger connections. Never assume that you have a good connection! Check, check, and check again. Even the smallest amount of corrosion could prevent a good connection.  Once thoroughly inspected, failure to charge is a sure sign that your battery has “gone to a better place.” If possible, you can also verify with another charger, but the problem is rarely the charger itself.

There it is, the top 5 signs that your motorcycle battery is bad. You’ve learned that there are several ways for a battery to go bad, and hopefully, you’ve learned “how to tell if a motorcycle battery is dying?” It could be a lack of use, lack of charge, lack of maintenance, or simply a worn-out battery. But if your battery is experiencing any of the listed symptoms, it is time to do some testing and, if needed, start shopping for a quality replacement battery.

If you want to learn how does a bad battery affect a motorcycle? Or, how do I check my motorcycle battery health with a multimeter? We have tons of info in our Knowledge Base. Feel free to call our tech line or email our battery professionals. See, there are just so many ways BatteryStuff.com can help!