Manufacturers place the batteries’ lifespan at around 4 years. However, this may vary according to how often you ride your motorcycle. Some riders claim their battery reached 10 years before running out of power, without any maintenance. It’s worth mentioning that brand name batteries last a lot longer than non-brand name ones.
Here are a few methods that you can try in order to find out how much power your battery still has. They can be performed anytime and anywhere. Moreover, most of them do not require the use of additional tools or instruments.
These methods are simple and can be performed without any tools. Just before starting the motorcycle, take a look at your dashboard. Most of the times, even if your battery is almost depleted, it will still have enough power to light the dash. However, you want to watch if it flickers when you press the electric start button. If that happens, then your battery needs to be replaced.
Another thing you can do before riding out to check the power level of your battery is to use the horn. If you press the button and the sound is weak or you hear the volume go down as you use horn, then your battery is nearly drained out.
For visual inspection, you must first remove the motorcycle’s seat or a side panel, depending on the model. The good news is that this is the hardest part. To visually inspect the battery, there are a few things you need to look for.
Search for any physical damage visible on the battery, such as cracks, ruptures or bulges in the casing and loose or broken terminals. Loose terminals present a risk as they can short circuit. If this happens, the battery’s power is instantaneously unloaded resulting, in high temperatures that will burn and melt the surrounding materials. Some batteries may even explode.
Bulges and bumps visible on the casing are usually the signs of overcharging. Holes, cracks, scratches and other similar surface marks are most likely the results of mishandling the battery. Although these visible defects may not stop the battery from functioning, it is highly recommended to label it unsafe, dispose of it properly, and replace it as soon as possible.
Wet-cell batteries, also known as flooded batteries need their water level maintained. If the water level is low, adding distilled water will help most of the times. A dry wet-cell battery causes sulfation build-up because the plates from the cells come in contact with oxygen. Sulfation is the number one cause of early failing batteries.
Therefore, responsibly maintaining these type of batteries makes a big difference in how long they last. It is worth mentioning that charging wet-cell batteries after they’re already dry will do nothing else but burn them.
Another sign of a bad flooded battery is the fluid color. Even if it’s full, a brown or dark color fluid indicates that the battery must be replaced. This also applies in cases when just one cell has this brownish color.
Use a digital multimeter
Digital multimeters are inexpensive and help you tremendously around the house. As your bike is powered by a 12V battery, set the multimeter to measure the DC voltage, and turn the button to indicate the 12V or the next higher value available on the device. Most digital multimeters have 20V on their scale so set it there. Connect the test leads to the device and turn it on.
Before connecting the test leads to the battery, turn the bike’s headlights on for about 2 minutes without starting the engine in order to get rid of any residual charge. This will give you a precise reading of the voltage afterward. After a couple of minutes turn the lights back off. Connect the red cable to the battery’s positive terminal and the black cable to the negative terminal.
Without starting the engine you should already get a reading on the multimeter display. If everything is fine, the displayed value should be between 12.7V and 13.2V. This would indicate a fully charged battery. If you get a reading of around 12.4V, then your battery is roughly 75% charged. 12.2V corresponds to a 50% charging level and 12V translates to a 25% capacity.
Any value between 0V and 11.9V means that the battery is discharged. If the multimeter shows 0V this could also mean that the battery has short-circuited.
After that, it’s time to crank up the engine. Just when the engine starts you will see for a split second a drop in the voltage, which is normal. However, you do not want that reading to drop below 10V – 9.6V. Any value below that is an indication that it is time to replace the battery.
After the engine starts the displayed value will be higher than 12V and will hover around 14V – 14.5V as the battery is being charged by the generator.
If you have a multimeter, you can perform another test that will allow you to identify what electrical equipment, if any, drains your battery more than it should.
Remove the cable connected to the negative battery terminal. After setting the multimeter to amp read, connect the red lead to the cable you just removed and the black lead to the negative battery terminal. If the reading is 0A, this is a good thing as there is no parasitic amperage draw from your battery.
However, if you see a reading you have to start disconnecting electrical devices from the battery and measure again until the reading is 0A. This is how you identify the faulty electrical equipment.