Bicycle Dynamo's to charge mobility scooter batteries

Thread Starter


Joined Aug 23, 2021
Hi good people I am new here I am looking at trying to put some more power back into my mobility scooter batteries with some 12-volt bicycle dynamo. Am I barking up the wrong tree or is it reasonably easy to do do do. There are currently two 12-volt 36ah batteries and there is room to fit to bicycle dynamos that kick out 12 volts 5 amp. I am only trying to get a little bit more mileage out of the scooter than I am getting now. The batteries are new on the scooter but currently only getting about 4 miles I could do with getting a little bit more please help
Gummibear 28


Joined Jan 29, 2010
Hi Gummi.
Problem is that power to drive the dynamo will be drawn from the existing battery pack, so on level ground you will get less mileage.

IF you fix it so that the dynamo only kicked in while free wheeling down a slope and disengaged while on the level or going up a slope, that may give you a little extra mileage.

Remember the old trams used that technique, regenerative braking


Joined Aug 7, 2020
Hi good people I am new here I am looking at trying to put some more power back into my mobility scooter batteries with some 12-volt bicycle dynamo.
Presuamably you must have someone cycling alongside, pedalling a bicycle to provide you with the extra power!


Joined Jan 23, 2018
OK, all the responses have been correct IF you were thinking to spin those bike dynamos with the mobility device's wheels. What can work is using a stationary exercise bike to spin them when not riding the mobility vehicle.
So really, the basic concept is incorrect, as there is no way to achieve greater than 100% EFFICIENCY. Solar cells as a shade will deliver a bit of charge. A SMALL 2-stroke engine direct coupled to an alternator that delivered 24+ volts to charge is a possible solution, it might need to ride in a small trailer. But in california you could not even own it, much less use it.


Joined Sep 24, 2015
The first rule is you can't get something for nothing.
Exactly. The power you can generate will require taking power away from the wheels. In the end you will go a shorter distance. However, those bicycle dynamotors are designed to spin much faster than the wheels of the mobility scooter. It will be a big fizzle. Video tape it and put it on YouTube. Maybe you can help someone else understand that you can't get something from nothing.


Joined Jan 23, 2018
What can work for extending the range would be a small trailer, like a bicycle baggage trailer, possibly, that would carry an additional set of batteries. The trailer will need to have very low rolling drag, so probably 20 inch bike wheels not the fat mobility scooter style ones. Then you could have a golf-cart sized battery pack and go may more miles. And the same trailer can also have a section above the battery pack to carry all of your shopping bags home from the store.