Driving a LED with charge pumps

[jhonn]

I want to power a 50W LED using some 18650 li-ion batteries.The LED needs 33v, so, i've been thinking if i could use charge pumps to step up the voltage from 7.4v (two cells in series) to 33v, and then use a filter capacitor and a voltage regulator to reduce ripple.I know those pumps output small current, but what if i put 2 or 3 of them in parallel ?Any suggestions will be appreciated.


P.S.: i have no access to transformers.

 

[rajakumarn]

Even though the parallel combination might work but the battery drain too fast and lasts no longer.

 

[BradtheRad]

To get 50W from your 7.4V battery bank, you must draw 7 amps continuous.

It would require several stages of voltage multipliers to step 7V up to 33V, and you would only get maybe 300mA.

 

[tpetar]

50W at 33V is too much for low voltage batteries. You will have bad efficiency and big loss in this voltage convertion.

 

[Tahmid]

Instead of charge pumps, you may use a boost converter. While current handling capacity may no longer be an issue, losses and thus backup time may be issues. Keep that in mind.