Charge while riding?

Well, a 6v battery will work the best. The white wire puts out an average of a little over 6v (you need more voltage than the battery to charge it). An RC car pack may work but it would have to be NiCd or NiMH because a Lithium battery requires special circuit, but NiCd or NiMH like to be fully charged and discharged. They wear out quick if you keep them topped off.

I would recommend a 6v lead-acid lantern battery. They're relatively small and they have high amperage to power a horn or high-intensity lights. It charges well off the white wire or a dynamo. You can find them cheaper than this, but here's an example: UPG Sealed Lead-Acid Battery

You do not need a diode between the white wire/dynamo and the rectifier at all, in fact, that will cut performance/power output in half. Put any diodes AFTER the rectifier, on the DC side. The purpose of the diode I'm recommending is to prevent the battery from discharging into the rectifier circuit (it shouldn't do that anyway, but the capacitors may "leak" a little current.) Other people use a diode directly on the white wire as an inefficient rectifier, for if they don't have a bridge rectifier. All a diode does is make sure current goes only one way, like an electrical check valve. An AC power source has positive half the time, negative the other time. A Diode just blocks the negative, so you only get power half the time. A rectifier "flips" it so you get full power all of the time. Putting a diode between the rectifier and white wire blocks the negative, so the rectifier can't "flip" it. The rectifier is redundant if a diode is used on the white wire.

A good sized diode to use on the battery would be 3-amp. Even though the battery is larger than 3amp, you're only trickle charging from the rectifier, and you won't go over 3amps unless something shorts out. Diodes

I really should make videos or more step-by-step instructions on how to make a complete electrical system. I know it would help a lot of people, as this seems to be a more and more common thing to add to a bike.

Ok, sorry took so long to get back, I've been laid up for few days with the worst flu ever. The backup sanyo bottle dynamo & light r not connected 2 the mag circuit in any way at all, except the earth thru the frame. Cheers

banzo said:

Sturmey Archer makes a front hub that generates 6V/3A while you're coasting. I'm looking for info on how to add a simple battery to store juice during the daytime ride and use it for nice led lights at night? Any DIY sites that explain how to design a simple charging circuit for 4 x "C" rechargeable batteries ought to do the trick...

Click to expand...

If you get to the final result it would be of great help. I can use LED lights without worrying too much about battery consumption.

If you have a dynamo, you won't have to store power in a battery for night rides. The dynamo will generate enough for the lights. Some headlights and taillights have an extra feature called a "stand light" that allows for the light to remain shining for a few minutes after the bike has stopped. Peter White cycles has really good quality versions of these, among other places.
I hope this helps

This circuit should help you guys out. I haven't built this one yet, but it is based on circuits I have built before like it. More info to follow.

Cool Dracothered, this'll b better than the 4 x 1A/40V Schottky diode bridge rectifier + 1 Schottky blocking diode I've got charging 4.5Ah SLA/26 Watt Halogen headlight. I dont do a real lotta night riding but its good 2 c & b seen when I do. Solid state/semi conductor electronics isnt really my thing, I do a little outta nescessity sometimes, valve (tube) guitar amps r more my thing. Cheers

Pilotgeek-
I left a message on your profile page. It would be great o get your thoughts when convenient.
Thanks

So, since my lights are made for a hub dynamo, can I run the lights directly off the dynamo WHILE ALSO charging my horn battery in parallel. On the horn/battery branch I would add the rectifier etc.

H20rider said:

So, since my lights are made for a hub dynamo, can I run the lights directly off the dynamo WHILE ALSO charging my horn battery in parallel. On the horn/battery branch I would add the rectifier etc.

Click to expand...

If I remember correct those dynamo's put out AC voltage so to use it to charge the battery it will need to be rectified (turned into DC voltage).

This will help some in what you are asking. http://www.nscl.msu.edu/~daniel/comp.htm

Hello, wonderfull thread, it just so happens that when i bought parts for rohmells CDI, i bought a few of the wrong items, one being a full wave brige rectifier and the other being a LM317T Positive adjustable voltage regulator.
how would i set this circuit to Limit voltage to 7.5 volts, and i have a computer power supply that i got the parts from, it has 2200uf 10v caps in ith all black with blue stipe with dotted black line in it one on side would useing these caps work?? woudl it add more capacitance? does more capacitance mean a bigger trickle for my pickle(battery lol)???

Hi,
This will probably be a little long winded..... Here goes....
I`m at where you were at 7 years ago, similar/same problem. Built a motorized bike, electric start, cdi, 12v battery. It got stolen, local pasty poor breeds, pic before the lights were added.


so I`m at building anothery. 80cc. The motor has an alternator built in allegedly. However, as I am adding lights, Headlight, taillight, brake light, indicators. 45w halogen headlight (huge 7" with built-in indicators, sort of grew on me may change it, for a smaller one like had before),

2-4w on taillight & 2-4w on indicators when they`re on, negligible. I might be being a tad of a worry-wart about it, however, It is alleged that the spark to the spark plug may suffer some performance problems.
Here is what I have at hand to use see picture:


& possible place to mount on motor drive chain side when installed, couple of pictures: {this is the 24v200w drive motor, it is harder to turn than the wiper/heater blower motor}

,

Using the wiper/heater blower motor, need to make a sprocket or find a bush.
End up making sprocket. {limit 5 images so, no sprocket}

Now, I`ve read a few posts, however, can`t seem to get the gist of some, 12v is 12v so, my thinking is along the lines of a voltage regulator perhaps from a vehicle, or simply a 30A or better, 12v charge controller like the solar charge controllers (example: http://amzn.to/2oYRQvr on Amazon, can view on ebay or elsewhere too etc.)

Concern was/is overcharging battery, but again connecting it, both motors outputs have positive & negative bias, spin one way +ve, the other way -ve. No F or D markings, just black wire, red wire.

Any thoughts on the "solar controller" notion?

Thanks Guys

If you want to see more on the prior build {the one that got knocked off after the second bike went {chain padlock & all} See/Read here : bit.do/NiksBikeProject12032017

Somebody needs to design an electric box for use with an sa dynohub. A diy with parts list. Great platform for a front wheel being disc or drum with sealed bearings. Even since 2012 there's not much. Guess you could probably grab a box off a pitbike.