Battery Chargers & Power Supplies

Common battery charging questions: 

1. Can I charge my ebike battery while I ride?

2. Can I buy solar cells to recharge my ebike batteries?

3. How can I charge my ebike battery to 80% for storage when my charger only charges to 100%?

4. Where can I get a fast charger for my ebike battery?

5. My ebike charger get very hot. Is that normal?

6. Do I plug my charger into the wall outlet and then into the ebike battery?

7. Can I finish my ride and immediately charge my battery?

8. How common are ebike battery fires? 

Can I charge my ebike battery while I ride? In general, it is not possible to hook up your charger to a battery backup or power supply device and ride at the same time. The Battery Management System (BMS) located in your bike or as a component in the battery itself, may limit that.  Also, the power supply station will be very heavy to bring along on your bike or trike and will reduce your bike's range. That is more weight that you and your bike's motor, will need to propel. 

Can I buy solar cells to recharge my ebike batteries? The solar cells that are commercially available don't have enough output to really contribute to recharging your ebike batteries while you are on a ride or during a rest stop.  This is why, with very few exceptions, that you don't see electric vehicle exteriors covered with solar cells. I have a 200 watt GoalZero set of solar panels and it takes a few days to charge up my GoalZero power station after it has recharged my ebike's twin 10Ah batteries. 

How can I charge my ebike battery to 80% for storage when my charger only charges to 100%? The best somewhat reasonably priced and configurable  charger is made by Luna. https://lunacycle.com/luna-charger-48v-advanced-300w-ebike-charger   The Luna unit allows the user to configure a percent of battery voltage, like 80% that some brands suggest you charge batteries to for storage or for longer life.  Once it reaches that setting it shuts off.  However, the BMS can get involved and confuse the charger. The charger may go to 80% and turn off as designed only to a few minutes later to magically turn back on and take the battery to 100%. If you charge a Lectric bike with a Luna charger it will probably not give you the 80% charge result you seek.     

Where can I get a fast charger for my ebike battery? You can purchase a fast charger for most of the common battery voltages. You should check the battery label to see if it specifies a maximum charge rate. On Lectric bikes there is a  2 amp charger used. Most manufacturers will provide a charger that provides the maximum  charge rate that their ebike battery can handle.  Note: We have listed 48V 3A and 4A chargers available on Amazon. If you are using them on a Lectric bike or other bike with a OEM factory of 2A this usage is at your own risk. 

If you need to be able to do longer mileage between charges because you are running out of battery capacity, there are safer options:

A. Buy a long range battery for your bike if that is available.

B. Use an extra battery you can swap out.

C. Get a battery balancer and a secondary battery to double your mileage.  See the Battery Balancer page for an explanation on balancers.

All these options keep you from taking a chance on destroying your battery or causing a fire which will destroy your bike and possibly a lot more.

My ebike charger get very hot. Is that normal? Ebike chargers can get very warm. We have measured the OEM Lectric 2 amp charger at over 130 degrees.  Be sure to position the charger on a surface that will not be damaged by the heat. 

Do I plug my charger into the wall outlet and then into the ebike battery? Nope - the opposite. Most ebike manufacturers recommend that you first plug your charger into the ebike battery charging port and then into the wall outlet. This reduces the possibility that you create any arcing that could eventually pit the charging contacts. It is important to not let kids play near your ebike. The obvious risk is a heavy ebike falling off its kickstand and injuring the child. The less obvious problem is a child playing with metal objects like a paper clip or other small conductive object near the battery's charging port and shorting out the battery. This can blow an internal fuse in the BMS or ruin the battery altogether. Yes, it has happened. 

Can I finish my ride and immediately charge my battery? Most ebike manufacturers will recommend that you let the ebike battery return to the ambient temperature before beginning charging. Because the batteries on many ebikes are enclosed and you might normally charge the battery while it is in the frame, it may be difficult to determine if the battery has cooled off or not. For me, I have waited a couple of hours before I hook up my charger. 

How common are ebike battery fires? One of the very common questions that newbies ask is about is the danger of battery fires because of news reports they have seen. I follow all the Lectric groups and there have been only one or two documented instances of a battery fire caused by the charging of Lectric bike batteries. 

As reported by a major consumer advocate group, a potential contributor to these fires we have seen in the news are under $800 bikes sold on Amazon that may have circumvented the most basic safety regulations in what is known as the “Amazon loophole”.   

Lithium-Ion batteries are flammable and will catch on fire if they overheat and potentially catch fire from a direct short circuit or from being in a fire caused by some other ignition source.  

The common denominators seen in the battery fires that make the news are modified batteries, using non-factory chargers to fast-charge batteries or charging large number of batteries simultaneously in older buildings with questionable wiring. If you plug twenty 2-5 amp chargers into multiple power strips on a single 15 amp residential circuit and the breaker does not pop, bad things can happen to the home or apartment's wiring inside the walls. 

It makes sense to turn off or disconnect your charger from the bike, once the green light is displayed. Some Lectric owners are using a countdown timer to cut power to the charger after a configurable number of hours. The timer we have listed here is fine with the following caveats: 

1. If you cut power to your charger with a timer but leave the charger connected to your bike, we have seen reports that slight resistance in the Lectric charger’s design can drain your battery. We have tested that and are unable to duplicate the issue so far and it might take a lot longer than we could test for. 

2. If you use a timer, you will have no visual confirmation by the charger's green light that the battery was ever fully charged. If the battery needed a 4 hour charge and you set your timer for 2 hours, the battery won't be fully charged for your next ride. Eventually, before your next ride you may want to plug the charger back in to see the green confirmation light or turn the bike on and check your volts reading to be sure it is the 53-54+ volts of a full charge.