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Tips on Determining Your E-Bike’s Battery Health

Tips on Determining Your E-Bike’s Battery Health

Running on empty: it’s a bad position to be in on your e-bike. Picture a scenario in which you rely on your pedal assistance to make it home at the end of a long day only to find out that that extra boost isn’t there when you need it. Suddenly, conquering a hill is much tougher, you’re pedaling much harder, and by the time you walk in the door, you’re not ready to sit down for some quality binge-streaming—you just need a nap. Or imagine starting your day on an unexpectedly dead battery. You’re forced to show up to the office drenched in sweat and utterly unpresentable, all because you couldn’t enjoy the easy ride you were accustomed to.

E-bike ownership involves a few extra responsibilities. Among them is proper battery maintenance. In some sense, your battery functions as your e-bike’s gas tank. However, while external weather conditions can affect both gas mileage and battery range, a challenge unique to an electric system is the reduction of battery life due to the passing of time and bad maintenance practices. To help you monitor the state of your battery and get the longest lifespan possible from your e-bike components, we’ve put together a few tips on determining your e-bike’s battery health.

Before we get to the particulars of testing, it’s important for your e-bike’s battery to put its best foot forward, so to speak. Before running any diagnostics on your battery, make sure that it has a full charge. Even if you have questions about the potentially diminished capacity of your battery, it’s best to have it at whatever capacity that may be before you attempt to measure its vital statistics. Don’t make testing a spur-of-the-moment decision—charge your battery overnight before taking a closer look.

Use a Multimeter

Once you have a fully charged battery to work with, testing your e-bike’s battery in earnest begins with a handy tool called a multimeter. As its name would indicate, this instrument can measure numerous different electrical properties. By connecting your multimeter to your battery, you can obtain several readings pertinent to the state of your battery. While some images of old-fashioned analog models can appear imposing with their needles and fine print, you can purchase an easy-to-read digital multimeter from your nearest home improvement store. This will be an important part of your e-bike toolbox.

Once you have your multimeter in hand, it’s time to begin testing. Because we are, of course, working with electricity, safety is key. Consult your multimeter manual for safe testing practices to avoid shock or electrocution. Your manual should also instruct you on how to best connect the multimeter to a variety of different battery types. Remove the battery from the bike frame and connect your multimeter.

Once connected, there are three aspects of battery health you should note. Fortunately, for people of a certain age, they form a familiar acronym: VCR. No, not a video cassette recorder, but rather the trio of voltage, current, and resistance. What does this VCR mean to the state of your e-bike’s battery?

Measure Your Battery’s Voltage

There are lots of terms surrounding electricity, like volts and watts and amps. Let’s zero in on the first one, a number which we hope is anything but zero. Voltage is electricity’s measure of work, a figure that is pertinent to a motor. The multimeter should tell you the voltage of the battery. Ideally, this value lines up with the specifications of your battery. For instance, if you purchase our 52-volt Whale Shark e-bike battery, your multimeter should read “52V” or something very close. In examining a full battery that is not in use, testing may even yield a higher voltage than your battery specifies. If you notice that your voltage readout is significantly lower than it should be, however, this is indicative of a failing battery. This low voltage means the battery lacks the appropriate level of energy for the motor.

Tips on Determining Your E-Bike’s Battery Health

Check the Current

The second figure you should explore as you test the health of your e-bike battery is its current. We move now from voltage to amperage—the capacity, rather than the strength, of the electrical current. In other words, how much electricity is flowing through your battery? Your battery’s specifications will likely denote its current in terms of amp-hours, which is a measure of current over time. To give an example, a battery that boasts 17 amp-hours would be able to deliver 17 amps of electricity over one hour, one amp over 17 hours, or any intermediate way in which you choose to do the math. If your multimeter shows that the battery’s current is weaker than its specifications indicate, this is another sign that the battery has lived through too many charge cycles and is losing its ability to provide power.

TIP: Before you test for current capacity, remember to make sure your multimeter is set to measure direct rather than alternating current.



Resistance: Ohm Sweet Ohm

The final third of our VCR trio is resistance, or the extent to which an object pushes back against its electrical flow. We measure electrical resistance in ohms. It’s a figure that we can obtain by doing an equation appropriately called Ohm’s Law, which dictates that resistance is equal to a current’s voltage divided by its amperage. Of course, thanks to a multimeter, you can forget about physics and algebra for now and determine your battery’s resistance simply by plugging in. Ohm’s Law can already tell us that if your amperage is dropping, your resistance will go up, and as resistance increases, your battery’s efficacy decreases. That means you’ll have a tougher time charging your battery and could be looking at some perilously low battery ranges ahead.

Replacing an Unhealthy Battery

By taking these tips to determine your e-bike’s battery health and noting these important readings, you can keep better tabs on the lifespan of your battery. However, the awful truth about all batteries, whether they’re lead, lithium, or otherwise, is that they all have finite life spans even with great care. When you exhaust a battery’s limit of charge cycles, decline comes on fast. Before it does, prepare for replacement by exploring the Ebike Essentials collection of electric bike batteries for sale. Find the battery that’s right for your motor’s voltage and get ready to enjoy a long life span.

by Ebike Essentials