Just a thought. I'm presently cycling some old Electron (Nicad?) batteries as I've persuaded 2 collegues to go night riding, but i have to provide all 3 sets of lights. This has got me thinking, could these old Electron batties be used to power the DX? They're 6V, 4+Ah capacity and use the same dc plugs as the DX. I believe the DX lithium battery is 8.4V therefore with the forward voltage of the SSC P7 (4×3.7V?), it must use a boost driver. Not that I can see right now why I would want to particularly, but could i use the Electon batteries to power the DX?

No Your P7 is 4 dies all connected in parallel so it only sees 3.7 volts @ what ever current the driver supplies

so your 6 volt should be able to run the dx bastid

depends on the light. The "DX Bicycle light" has a 4 cell 2+2 8.4V array with an 8.4V max input 2400mah constant current driver. Not sure of the lower limit of input voltage before it switches off. (I know if my cells go too low, the light wont swich on at all~) Also the capacity is about 5000mah plus of the standard cells so your nicads may dump quite quick if you are on full beam

The single cell torches have the 3.7v lower current driver i guess

A definite maybe there! Maybe not, maybe so but ultimately why bother cos its likely to be a bit pants. Curiosity hey!?!

curiosity is great! Plug it in.

I got all interested in drivers and the like. My first resistor based one got stupidly mega hot so I ditched that. Tried a voltage regulator based one which worked ok . (Rule of thumb here was minimum input voltage should be diode voltage + regulator drop out voltage; about 6V as it happens). This failed short circuit and destroyed my P7

bought a new 2800mah driver from DX in the end. 4 dollars!

some interesting info here though

http://www.instructables.com/id/Super-simple-high-power-LED-driver/ I based mine on this but used a 3Amp capable 5V voltage reg

oh and here is the LED resistor calculator. (you will need a MAN sized heatsink and be prepared to waste a lot of energy in heat)

for 2.4A current (nice brightness) you will need a 1ohm 5.8 watt resistor, a BIG heatsink and a P7 led! 🙂

http://led.linear1.org/1led.wiz

curiosity is great! Plug it in.

…..after all, what's the worst that could happen…..