how can i make my electric bike recharge while riding?
July 27, 2011 by pbik
Filed under Electric bike
I have an avg ebike but i would like to be able to put some kind of charger like the cars to be able to charge the battery while you move. my bike is 24v 12 amps
You know how hard it is to pedal without any power now try pedaling 3 times that hard to charge a battery. There are bikes that will charge the battery when going down hill instead of using brakes but to pedal to charge a battery is very inefficient.
cars that do that use the incredible energy density of gasoline to ‘charge the battery’
it won;t work powered by you
very very inefficient
you;d have to sit at home for 3 hours to put 15 minutes worth of riding into the battery
plus the generator would weigh a ton
and cost money
a lot
wle
What you are talking about is called regeneration. All motors can become generators. It depends on which way the motor is spinning.
Here’s the real problem with this tactic: the best motors that can be used for this are heavier than one that is not set up for regeneration. It takes more energy to start you moving than you get from the regeneration. That means a net *loss* of energy.
In a car where the distances involved, battery pack, and weight are orders of magnitude larger the regeneration can be made effective.
The best way to add some charge is to have a dynamo hub. But the cost for a 12 volt hub, its weight, its added drag, and minimal power output won’t make a dent in recharging the battery. At very best you might break even, but might still lose energy.
In gasoline powered cars they use alternators to charge the battery, but a typical car is 0.5% efficient in turning energy into forward motion. Yep, less than 1% efficient per Rocky Mountain Institute.
Perhaps the best improvement for a standard ebike is a better, more efficient motor. That way your bike weighs less and you use lose less energy too if it fits at all.