Hi,

Does anyone here know of a DIY battery charger where i can buy a pre-made PCB?
I see a lot of options out there but they all require you to fabricate your own PCB. Which i can not do.

I've made this one but am looking to upgrade to something that can power my headlight via batteries when the dynamo is not producing enough power. (at low speed)

Would be nice to have:
- a LED charge/full indicator
- battery over charge protection
- a switch to select headlight or usb
- auto battery backup for headlight at low speed


Something like this would be ideal if i could get a PCB made for me


AM I ASKING FOR TO MUCH**********

I've often wondered of these power supplies (designed for alarm systems) would work on bike dynamos:

https://www.altronix.com/index.php?pid=2&model_num=AL624

They have provisions for battery backup. Prebuilt as you request but untested for this application.

Best wishes with your search.

thanks jbabic.

I've heard of one guy using something like that before.
I'm looking for something that's a little more specifically built for cycling. I would like to build it myself. I like the idea of soldering but wish there was a kit out there that you can buy that already has the circuit board available to buy.

Here is another solar type charger that was used with a dynamo hub.

No , it is impossible - because you are not a large enough demand market. Tough break, but great idea!

I too have always thought it would be cool to do something like this. Unfortunately alarm systems (and other conventional battery backup systems) generally use SLA or gel batteries, which is what the link you posted is designed for.

I think what might work better would be an li-ion battery management chip designed for portable USB devices. The lights and other devices could run continuously off the battery, and the dynamo would keep the battery topped off. There might be some prebuilt modules floating around for this kind of thing, but I doubt there's anything that would be completely suitable off-the-shelf without some extra circuitry (for one thing the power draw would be a lot higher than what the chip was designed for).

For short term use, say a minute or two a capacitor ought to do the trick with *perhaps* better efficiency than a battery (engineers please correct my theory here.)

For more utility I think the current crop of dynamos need more output. 12V @ 1A ought to be real useful. Imagine the uses...

To address concerns towards the drag of such a generator one must keep in mind our limited ability to generate power and how one wants to use it - for transportation, for electrical potential, for bragging rights, etc. Pick your own.