I've been doing a DIY Wind energy generator. I'm also a newbie in this field. I would like to ask what will happen if I connect my wind turbine to a 12V rechargeable battery without a voltage regulator?
Don't let this happen to you:
Batteries don't like excessive voltage or current and will destroy themselves and injure others if proper steps are not taken to ensure these conditions do not occur. For these reasons it is very important that the charger you use is suitable to the battery. Remember,
Battery acid can blind or disable you.
Electricity can injure or kill you.
Please do research on battery and electrical safety to ensure these things do not happen to you. If you are determined to do DIY projects like this, follow the instructions exactly and make sure you trust the instructor enough that you can feel confident you won't be injured. In any case of uncertainty, ask before you try!