[copy from my private message]
Hi,
Yes, I noticed it is getting a bit confusing with all people telling different but actually the same things.
I'll try to make it clear.
In the initial picture that you showed, I see 8 cells on a table in 2 rows, but from the picture, it seems that they are not yet connected to eachoter. Is this correct?
Since you are getting the light from 350xfire, you should follow his advice. Many of the dealextreme or kaidomain LED drivers are designed to be used with 2 li-ion cells in series or 8.4V maximum. If you supply more voltage to the LED driver, you will likely destroy it because usually the capacitors are only rated up to a certain voltage.
That is why everyone keeps telling you to use a 2 cell or 2S4P batterypack. They do not mean that you should use a protection circuit for 2 cells on a 4 cells battery pack, but that you actually make a 2 cell (series) with 4 cells in parallel battery pack with a 2cell protection circuit.
Once the voltage (and number of cells) is right for the driver, you can play with burn time by putting 2 additional cells in parallel with the batterypack. The voltage will stay the same, but the capacity will add up (e.g. a 2500mAh cell in parallel with a 2500mAh cell will result in a 5000mAh batterypack which will double the capacity of a single cell battery pack and will double the burn-time of your light.
Now, for your specific configuration, you'll want to connect your cells like this:
Now you have your 2S4P batterypack. For the protection circuit, you'll need a circuit that is designed for a 2S setup, like this one:
http://www.ebay.com/itm/Protection-...326?pt=LH_DefaultDomain_0&hash=item4ab86786a6
or this one:
http://www.ebay.com/itm/Protection-...862?pt=LH_DefaultDomain_0&hash=item336ac821de
To connect this board to the pack, you'll need to make a slight modification to the conntections in the above picture. the connection between each 2 cells in series, should also be connected to eachother between the different strings, like in this picture which is an example of a 2S3P pack:
Where it says balance tap, you should connect your protection circuit and, if your charger supports it, a balancing connector to connect to your charger. You can leave out the balancing connector for now if you're unsure about that, it is there to keep the voltage of each cell the same.
Hope this helps.
Johan