Driving a LED with charge pumps

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jhonn

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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.
 

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

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.
 

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

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.
 
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    tpetar

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