max input voltage for 3x CREE LED Lamps?

[02gf74]

I think I know the answer but will throw the question out here anyway.

I have a set of 3x CREE LED lamps, like those below. They have a 4x 18650 rechargeable battery pack to givre 4.2 V; so are two pairs wired in parallel.

Can I connect the lamp to a pack with 4 cells wired in series, i.e. 8.4 V? (there are CREE LED lamps with such packs).

I do not know what is inside the lamps and I don't think it will be easy to dismantle them - but I have made my own LED lamps using a LED driver which takes a variable voltage (up to 18V or so) to provide the correct current.

In theory these should have drivers so should take a variable input voltage but how can I find out how high can it go before they go pop, if indeed they do go pop?

 

[yellow]

4x 18650 rechargeable battery pack to givre 4.2 V; so are two pairs wired in parallel.
4 cells wired in series, i.e. 8.4 V? (there are CREE LED lamps with such packs).

"two pairs in parallel" = two pairs that are wired in series and those two in parallel = 8.4 V
4 cells in series = 16,8 V


as to the question:
noone can really help.
Open the light and try to get data of the driver - some printing - then search for that piece.
And try to check how the led are connected ... if these are in series, then the driver must be a step-up, then there is a chance, that a 8.4 V pack might work.

If the led are in parallel and the pack is 4.2 V, then the standard 8.4 V pack is DOUBLE the voltage ... might work, You could try - but that pice will more likely be some kind of direct drive behaviour and might
16.8 V pack will definitly fry, whatever pack or led wiring is done