Good day!

I've been working on a small project (9V LED Lamp) which is powered by a 3S 18650 Battery.

Now, as far as I know, an 18650 battery shouldn't go below 2.8v, that times three (3S) is about 8.4V, and 4.2V per cell at maximum charge, which would be about 12.6 V at 3S.

I'll need to use a Buck converter to keep the Voltage constant from 12.6 dropped down to a constant 9, but when the battery voltage drops below 9v I'd like to boost it so from range of 8.4v to 8.9, I'm stepping it up to 9V..

That's why my question Can i use a Buck and Boost converter in series?

Is that even possible? or it's impractical? Maybe a better solution?

Regards,
Paolo

 

This is the one I've been eying on:

http://www.ebay.com/itm/Digital-Dis...491761?hash=item3f5042c131:g:59EAAOSwu4BVm0n7

It says Step-Up Step-Down converter. Does it mean it does both? A Buck-Boost Converter?

 

Yes, you need a buck-boost converter.

 

Yes, you need a buck-boost converter.

Hey thank you for replying so promptly!