Fat Tire Electric Bike Batteries, Everything you need to know.
The battery on your Fat Tire Electric bike is your source of fuel. You will need a bigger fuel tank if you've got a bigger motor. If you've got a smaller motor, a smaller fuel tank. Either way, that battery's size will affect your range.
Electric bike batteries differ in the way they mount to your bike and how you charge them. There are many other aspects that make a difference to their health and lifespan. So, here's our guide on e-bike batteries to answer any questions you may have and ones you may not have thought of yet.
DO E-BIKES COME WITH CHARGERS?
If you have an electric bike already, this is completely obvious. But if you're new to e-bikes, this is a very valid question: so, do e-bikes come with a charger? The answer is yes. The manufacturer will supply you with the correct charger for your fat tire electric bike with instructions on how to use it.
CAN E-BIKE CHARGERS BE UNIVERSAL?
Are e-bike chargers universal? Can the same charger be used on different brands of electric bikes? No, you cannot use one brand's electric bike charger on bikes from other manufacturers.
The first and foremost reason for this is that the voltages can be very different between chargers. In fact, the labels can be a little confusing.
For example, one might see a battery with a 54.6 Volt output. But, typically, you see e-bike batteries advertised as 36 Volts, 48 Volts, and sometimes 52 Volts. So what does a 54.6-volt charger even go to?
Well, the answer is 48 Volts. The voltage is the nominal or the typical voltage while you're actually using the bike and riding. It's not the maximum voltage or the charge voltage. These are not always labeled the same either.
You will see some e-bike batteries with an output stated as 54.6 Volts for a 48 Volt battery, while others might simply say 48 Volts. The same applies to a 36 Volt charger. Some say 36 Volts, but the actual charge voltage is 42 Volts. So if you have more than one electric bike, label the batteries if they have different voltages, so you're always using the correct one.
WATTS AND AMPS
How fast your electric bike battery will charge depends on its voltage (V) and Amp-hours (Ah). But an easier way to determine charge time is to look at the amps on the charger.
For example, if you have a two amp charger and a 48V, 10Ah battery charging at two amps, it will take five hours to charge fully. Two amps times five hours equals 10 amp-hours. It's very easy math to see how long it will take to charge a given battery with a given charger.
If you want to charge 50% faster, you need to bump up to a three-amp charger. If you went all the way up to, say, a five amp charger, that means it will charge in only two hours.
E-BIKE CHARGER PLUGS
The type of plug that comes on the charger varies. Some electric bike battery chargers have an XLR three-pin connector on one end and an AC adapter-type cord on the other, so they can work with either 110 or 220 Volts. The USA uses 110 Volts, and Europe and other counties use 220 Volts. If you're in Europe or another country that uses 220 Volts, the charger should come with the appropriate cord for your country.
Because most of the chargers are made overseas in Asia, they're often set to 220 Volts. So what happens if you're in the US and get a 220 Volt charger, plug it in, and nothing happens?
Well, your battery won't charge. But, usually, this is because the switch is in the wrong position. So just flip it over to 110 Volts, and it will probably start working just fine.
CAN YOU OVERCHARGE YOUR E-BIKE BATTERY?
Should you leave your fat tire e-bike on the charger when it's done, or should you pull it off? Does the battery overcharge if you leave it on the charger? What exactly happens when you plug in a battery to one of these and leave it there?
You'll notice that the e-bike battery charger has a small LED light in the corner. On most chargers, there is at least one red light while charging and a green one when it's done.
Alternatively, some chargers have two LEDs; usually, one is red, and they both turn green when the battery is done charging. These do stop charging when the battery is full. So there's no real danger with leaving it on.
In fact, if your battery is relatively new, you may want to leave it charging. This is because when a battery is still connected to the charger, it gives the BMS (battery management system), the circuit inside the battery, time to balance the cells.
It's actually a good idea to leave it on for a little bit longer every once in a while and give it some time to balance.
If you know the cells are balanced and everything's working well, we recommend unplugging it when it's charged. You don't want to leave it plugged in all the time every day of the week.
Basically, a battery consistently loses a little bit of voltage. It does this very slowly, but there's a slight drain on the voltage no matter what you're doing with the battery or where it's sitting.
This slight drain on the battery will cause the charger to charge it back up, continuously using up its charge cycles. Therefore, leaving your battery plugged into the charger 24/7 will prematurely but slowly wear out your battery.
E-BIKE BATTERY LIFESPAN
Every electric bike battery charger will charge the battery up to 100%. However, it is better for a battery if you only charge to 90%, as this increases its lifespan.
You can buy some electric bike battery chargers that are more advanced. For example, the Cycle Satiator has special functions allowing you to just charge to 80% or 90%. Although expensive at about $300, this charger is handy, especially if you have a bunch of different e-bikes or electrical things you need to charge.
Not only can you set different profiles for a specific battery, but you can also charge different types of batteries with it. Whether you have lead-acid or lithium-ion batteries like on electric bikes, you can set the amps to charge the battery slower or faster to suit your needs.
FAT TIRE E-BIKE BATTERIES BASICS
E-bike battery capacity is measured in watt-hours. The more watt-hours you have, the further you'll be able to travel on your fat tire e-bike, but that depends on the power of your e-bike's motor. So the capacity of your battery is linked to the power taken from your motor. And there are two different types of e-bikes.
Today's most modern, full-power e-bike motors have an average torque value of around 80-newton meters. Now I'm using this figure very loosely to give you an idea of when we compare lower-power bikes. The battery capacity range on such bikes is usually around 500 Watt-hours to 750-Watt hours.
On average, in a medium power mode to level 5 assistance, a 700 Watt-hour battery will give you around four hours of riding time. On the other hand, lower-powered e-bikes have an average torque of about 35 to 60 Newton meters. They also have smaller and lighter batteries of around 250 to 350 Watt-hours.
That lower-powered motor and the smaller capacity battery will give you roughly the same range. But, some manufacturers offer range extenders which are batteries that link into your bike's primary battery and are often carried in a water bottle cage or bolted to the down tube.
CHARGING YOUR E-BIKE BATTERY
The time it takes to charge your battery will depend on several things. Firstly, the size of the battery you are charging and the type of charger that you are charging it from. You need to consider these things, particularly if you're going on those longer trips.
From our testing, a standard Bosch charger charging a 500 Watt-hour battery will go from flat to a full 100% charge in just under five hours. Now, this can be made faster by purchasing a fast charger, which cuts down that charging time to about three hours. Both Bosch and Shimano have a range of chargers available.
The method of charging your e-bike is also going to vary massively too. Most e-bikes will allow you to charge the battery mounted or removed from the bike.
Removing the battery is helpful if you need to charge in a hotel room or something. But it isn't always convenient, as some electric bike batteries require lots of effort to remove.
If you're out and about on those big adventure rides, there are still plenty of ways you can charge your e-bike without plugging the charger into the main power grid. You can use a generator, a portable power bank, or an inverter from your car to get that battery charged up to the max.
Early e-bikes came with a battery fitted externally to the frame, meaning they were a bit odd-looking. But these days, you can expect more elegant battery mounting solutions, so much so that you can't always tell the difference between an e-bike and a regular bike.
Electric bike batteries can be mounted internally or externally on the frame:
Internal batteries fit into the bike's down tube and are usually accessed via a key or an Allen Key. This is the most common method of mounting a battery these days.
External batteries are straightforward to remove and often have a lower capacity. They're also super easy to carry as a spare or take away for security. There are also range extenders, which we mentioned earlier, usually mounted in your bottle cage or on your down tube.
REMOVING THE BATTERY
When it comes to removing your battery from the bike, you'll have a mechanism that holds it in place, and there are a couple of different options here.
Batteries held in place with a key are super secure, meaning the battery is more challenging to steal. But, it can be a pain if you lose that key or forget to pack it when you want to change the battery.
And lastly, you can get some batteries that are actually held in place with a simple Allen key. Now, this is super simple to use out on the trail, as long as you always have an Allen key to hand to remove that battery.
However, there are differences between brands. For example, Canyon uses a 4mm Allen key hidden into the down tube. This means you have that blend of security and ease of use.
Electric bike batteries can be pretty weighty, and it's something you definitely want to consider if you're carrying a spare. Its weight depends on the size and the watt-hours within that battery. For example, a Shimano 500 Watt-hour external battery weighs 5.8 pounds, and a 625 Watt-hour battery from Bosch weighs 7.7 pounds.
How To Look After Your Electric Bike Battery
Now that we talked about all the basics of fat tire electric bike batteries such as chargers, amps, and types of batteries. We are going to talk about maintaining your e-bike battery.
Maintaining e-bike batteries is not hard. In fact, in my opinion, they are the easiest component of an e-bike to look after. They also last longer than pretty much all the other components on your bike. But following these tips will give you many years of use from an e-bike battery, saving you money.
Don't Discharge Your E-bike Battery Completely
Don't discharge a lithium battery completely, as their chemistry differs from lead-acid, nickel-metal hydride, or nicad batteries.
Does that mean you can't go for a ride on your e-bike until the battery dies and shuts off? No, it doesn't actually because every battery has something inside called a battery management system (BMS).
The BMS is a smart little circuit board that monitors the voltage of individual cells. So to put this simply, the battery knows the status of all the cells. Therefore, it will cut off the battery when the voltage gets down to a certain point to prevent your battery from getting damaged.
So when you drain the battery until the bars on your display go down to nothing, and the whole bike just shuts off, the voltage is not at zero or anywhere close to it. The cells still have a fair amount of voltage left, but that's where they need to be cut off for longevity.
Understanding E-bike Battery Charge Cycles
How many charge cycles can you get? When we talk about charge cycles, it's easy to get confused, so what is a charge cycle?
A charge cycle is when the battery does a full discharge followed by being fully charged. So if you're starting with the battery at a hundred percent capacity and you drain it down to where that BMS effectively cuts the voltage off, that is a complete charge cycle.
Most electric bike batteries are good for somewhere between 800 and 1000 cycles, as this is what these individual cells are often rated for.
So, if you ride your bike for 20 miles on a complete charge cycle, and you could do that a thousand times, that would be 20,000 miles. That's a lot of mileage on an e-bike.
You may come across batteries suitable for as little as 500 charge cycles. This will take about 10,000 miles before you wear your e-bike battery out.
If you only use 50% of your battery power instead of draining it all the way to zero, that is effectively only half of a discharge cycle.
Charging your Battery
Now, when we get into charging, this is where there's a lot of interesting information about charge percentages. Most e-bike chargers that come with your electric bike will charge to 100% every time, and that's okay.
I don't want anyone to think they're killing their battery by charging to 100%. Those cycle ranges I just gave you are normal expectations. If you are charging to 100%, you're doing so because you want the most range you can get out of your battery.
As we've already mentioned, you can extend your battery's lifespan by charging to slightly less than full capacity. Charging to 90% puts less stress on the internal components of those cells, extending their life to more than 800 cycles. If you consistently only go to 90%, you may get as many as 1000 cycles.
Some studies suggest that at 80% charge, you might get double the number of cycles before that battery dies. Personally, we always charge our e-bikes to a hundred percent. In theory, it might last longer at 90%, but I know I will lose 10% of the range every time if I don't charge it fully. It's a trade-off.
Storing Your E-bike Battery Properly
What is the best percent of charge or voltage to store your battery? Different voltages will actually cause different things to happen within the battery. Now, typically most batteries will slowly drain or lose voltage over time. So you do not want to leave your battery dead for weeks or months.
You may go to plug your battery in, and nothing happens. It doesn't want to charge because the cells have gradually dipped below the lowest safe voltage to charge. The BMS will not allow those cells to charge; your battery is toast.
Now, if you leave your battery fully charged for a few days, it will be fine. But, if you know you'll leave your battery unused for a few months, you need to partially charge it.
The optimum percentage of charge for storing lithium-ion batteries is about 70%. This keeps the cells balanced as they're not sitting there stressed from lots of charge or lack of it.
To get to 70% charge, you can just monitor the display on your bike and switch the charger off at the right time. Alternatively, you can charge to 100% and go for a five-mile ride around the neighborhood to bring it down a little bit.
Hot And Cold Temperatures
Now do batteries like being left out in the cold? The answer to that would be no. If you left your e-bike outside or in the garage and the temperature is freezing or below, do not charge your battery. Batteries don't like the cold; unfortunately, you can cause permanent damage by letting them get chilly. It's better to take your battery inside.
It's okay to take a room-temperature battery outside and go for a wintery ride. But you may notice a loss in performance if it's freezing, meaning your battery won't produce quite as much power.
The bike might feel a little sluggish and may have a reduced range too. If you know you will be out for a while, we recommend insulating the battery in some way. Some people design custom sleeves that go around them. I've seen people put their batteries in a triangle bag in the frame.
The same goes for leaving your e-bike battery in the sun. When your battery gets too hot, its lifespan can be affected, as the heat degrades the battery.
You should avoid exposing your electric bike battery to extreme temperatures if you can help it. It's best to remove the battery from the bike to help its performance and overall longevity.