Having some questions during building a bike-generator

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Hello,I am building a bike-generator. Well I have found a few articles about that on the internet, but I have put together a list of questions and I would be really appreciated if someone could answer them (see below)

The goal: To have a bike, and by pedalling on it generate electricity, which will charge a battery. The battery will be then used to power multiple USB outputs (smartphone charging)

My setup: I have connected a dynamo from old car (14V, 42 amps) to a bike. Then I have a battery(http://www.kynix.com/Parts/5570/A23C.html)(12V). My setup will look like this:


And I have a few questions about this:

1.Is this form of "charging" suitable? How do I limit the current, so when pedalling faster (-> more current), I won't destroy the battery?
2.Is it possible to use the voltmeter VM1 to monitor the charge level of the battery? Or how to do it?
3.Can I plug smartphone into the USB ports? Is it safe? Can I use PolySwitch fuses?
4.Will this even work? :) Or any other comments/suggestions/etc. appreciated

Sorry for any mistakes in my English
My level of understanding electronics is somewhere near medium-low, I learned it all by myself, so I hope this isn't a total nonsense :)
Thanks in advance!
Hello ,

Yes , this form of charging is suitable , but it needs some optimisation.

If your battery is lead-acid type , you must charge it with constant voltage , if it is nickel-cadmium type then you must charge it with constant current.

The voltage or current requirements printed on the battery.

For a 12 volt lead-acid type battery , you must fix the voltage around 14.4 volts so you need a voltage regulator. Some car dynamos have a regulator inside and give constant voltage , simply check the output with a voltmeter.

Others give voltage proportional to revolution and needs a voltage regulator. You may find such regulators on auto parts store.

You may connect a voltmeter parallel to battery in order to check the voltage levels.

As far as I know , USB ports have 5 volts output , so you need to reduce the battery voltage to 5 volts to connect the USB ports.
You may use LM7805 regulator ( 5 volts / 1 amp ) to get 5 volts output.
To prevent overheating , use a cooling fin for LM7805.

Good luck !
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