Can I put more power to my light?

I currently have a Ultra Fire SSC P7 bicycle lamp.
It runs on 4 18650's and the pack puts our 8.4 volts.
I have a spare battery Ni-Cd 9.6 volt spare pack.
What will happen if I wire this pack into my light?

Rob

It would depend on how it is configured, if the cells are in series and then go through a buck converter than it should be fine, if the cells are wired in parallel with a linear regulator or direct drive it would instantly cause the LED to turn blue. Why not upgrade to something brighter and more efficient? The P7 has been around for a long time and it is inefficient, not very bright and since the individual P4 LEDs run in series and not parallel like the MC-E, a XM-L LED would be much better.

T g

Fuzzuki said:

I currently have a Ultra Fire SSC P7 bicycle lamp.
It runs on 4 18650's and the pack puts our 8.4 volts.
I have a spare battery Ni-Cd 9.6 volt spare pack.
What will happen if I wire this pack into my light?

Click to expand...

Well, your 9.6 v pack will put out about 11.2 volts when fully charged, which is indeed slightly more than 8.4 volts -- 33% more. (Obviously your current pack is wired in a 2s2p configuration.)

However, the odds are that your light has a regulator in it (and enough tolerance that it can handle 11.2 volts) and so it'll be fine. This is not certain, however -- you do have a chance of ruining your light.

If it does work fine, it will probably not be any brighter than it was before. (And if it is brighter than it was with the stock battery fully charged, I'd suggest immediately stopping the use of this new battery before it fries. (It might work forever, or it might fry.) The odds are that if it the higher voltage will fry your light, it won't do it immediately, so you'll have a few seconds to test -- but I wouldn't push it much longer than that if it is indeed brighter.

To be more precise about all this would require knowing what's inside your light, which I do not.