Think you can plug any old charger in, to power up your eBike battery? Hold on, it’s not that simple. Using the wrong charger can ruin your battery and be a fire hazard.
We take a look at how to select the right charger plus some good charging habits to extend the life of your electric bike battery.
Different types of chargers for electric bikes.
Chargers for electric bike batteries aren’t universal. You should always use one designed to suit your battery pack to maximise its life span and avoid fire hazards caused by overheating.
eBike batteries come in 12-volt increments, usually starting at 24v (for small bikes) moving up to 36v (for a standard bike) and then 48v-52v (high powered bikes).
The majority of eBikes fall between the 36v - 48v range.
Here is an example of pairing the right battery voltage with the right charger voltage:
- A 36V bike should have a charger that goes up to 42V
- A 48V bike should have a charger that goes up to 54V
When choosing a charger, check the charger connection point is compatible with your battery. Some chargers have a 1-pin or 3-pin connection, for example.
If you’re buying the charger online, you’ll also want to make sure it can be plugged into an Australian powerpoint.
Many eBikes are sold with a compatible charger but it is important to know how to make the right choice if replacing or buying a spare one.
How long does it take to charge an electric bike battery?
Fully charging a battery typically takes between 2.5 - 6 hours, depending on the type of battery charger.
Here’s how to work out how long a charger will take to charge your bike battery:
Let’s say you have a 48-volt battery with 10 amp hours* and a 2 amp charger.
*Amp hour is the rating used to tell you how much amperage a battery can provide for exactly one hour.
Divide the amp hours of the battery (10) by the amps of the charger (2) to get the number of hours it will take to charge. 5 hours, in this example.
10 amp hours / 2 amps = 5 hours
If you want to charge the battery faster, you’d need to use a charger with more amps.
For example, a 5 amp charger would get the job done in 2 hours (10 amp-hours / 5 amps = 2 hours) but a faster charge isn’t always a good thing. Charging at a slower rate is healthier for your pack.
Should you leave your bike battery on the charger?
We don’t recommend leaving your battery constantly connected to the charger while the charger is plugged into power.
Whether the battery is in use or not, it’s losing tiny amounts of voltage all the time. If you’re putting your battery on charge all night, every night it actually wears the battery out faster.
Plus, overcharging will cause the battery to heat up which can become a fire hazard.
Charging a battery to 90% rather than 100% each time you charge will help increase its overall lifespan. You’ll also boost battery longevity if you don’t top up the charge after every single ride.
That said, you want to avoid allowing the lithium battery to drain completely - put it on charge when it’s around 30%.
Even if you haven’t been using the bike, we suggest recharging your battery at least once a month.
Charge your battery in a cool place
When riding and charging, your eBike battery doesn’t like extreme temperatures.
Charging below 0°C or above 40°C won’t give you an optimal charge and can shorten the battery life span. While riding you should also be mindful to park your electric bike in a shady or cool spot to avoid the battery overheating.
Most lithium-ion battery manufacturers give a warranty period for the battery - usually 500 - 1,000 charge cycles.
A single charge cycle is counted as charging the battery from 0 to 100%.
Let’s say you use 25% of the batteries capacity, then recharge to 100%.
You need to repeat this 3 more times to be counted as a full charge cycle: 4 x 25 = 100.
As we mentioned earlier, it’s better to avoid draining the battery completely (0%) or charging it fully (100%) if you want to maximise battery life.
Some of the more sophisticated chargers available allow you to cap the charge maximum to 80% - 90% so there’s no chance of hitting 100%.
Or, you can set a timer for one to two hours to remind you to check the charge status.
If you’re planning to head out for an all-day ride and want a full battery, charge it to 100% as close to the ride as possible.
This reduces stress on the battery by not having it inactive at full capacity for an extended period.