Peter_wadley said:
I am just wondering if you need to reverse the polarity when you charge batteries..
do you connect the positive voltage to the cathode?
ROFLO.
Think about it.
What happens when you connect two voltage sources in series?
They add.
What happens when the battery discharges?
Where does the current flow? For simplicity's sake think of current flow in turms of conventional flow, from the anode to cathode.
Now think of charging a battery.
Where does the current flow?
No offence intended but I think you neen to learn a bit more about ohm's law and current before you do this.
am always wondering "Will those leads shock me?" ... is there a set voltage that electric shock will happen? What is the resistance of a human?
There is no set voltage, it can vary enourmously depending on the thickness of your skin and how damp it is. Remember, it's current that shocks you not voltage, altough you can't have one without the other.
Sensitive parts of the body like the mouth can feel a tingle at less than 1VDC.
For dry thick skin you might only feel a tingle at voltages as high as 120VDC.
AC will shock you at far lower voltages than DC.
The IEE regulations state that in all live parts shall be insulated if their voltage exceeds 60VDC (ripple free) or 25VAC, in dry areas and 30VDC or 12VAC, in wet areas. I recommend you check the regulations for your area.
Generally, I avoid touching voltages greater than 12VAC or 30VDC as I often have sweaty fingers.