Series & Parallel LED Wiring

So as I understand so far, parallel form of a string of series is the way to go when wiring many LEDs.

Question is: Does it matter how many strings of LEDs I have within the parallel circuit? I am running it off of a switch which is connected to my 12V battery (WITH A FUSE OF COURSE!) As i understand, parallel will draw power from the source depending on # of LEDs , and series will provide the whole circuit with the same amount of power, (but it lessens the brightness of the LEDs?) this is where I am confused. I read many of the same topics but people always say both ways about the situation. Can anyone help? Thanks.

-Erik

as far as i know.. the LED will only draw the current it needs.. and generally its 20ma.

so you can connect as many leds in parallel to make up the amerage rating of the switch.

(amps will add normally not inversed like resistance)

LEDs are NOT resistive devices, therefore they will draw as much current as they are supplied with.  This is why you NEED to have a current limiting resistor installed somewhere in the circuit.

If you wire them in parallel all the LEDs will run at the same voltage, and will share equally the current made availible to them (which in most cases is the recomended amount of current for that particular LED).

In series they will all have the same current, but they will equally divide the voltage amonth them all.

With LED's not being resistive devices its not a simple Ohms Law relationship.

If it were me doing it I would wire all the LEDs up in parallel and use a current limiting resistor for EACH LED.  This way, if one goes bad the rest of the LEDs will be uneffected.  This may be impractical if you are using a large amount of LEDs, but shouldn't be too bad if you are only using a few.