Step up or down to output/ converter

[tao]

This is kinda neat..set the output voltage and it steps it up or down to hit it for... $ 10
Sunkee DC-DC Converter Module Step up and down In 3.5-28V Out 1.25-26V Adjustable (LM2596S+LM2577S)

[jackalope]

Forgive my stupidity but how could it regulate the voltage up? If the batteries are 7.2 volts and they start to go dead then where is tge voltage going to come from to regulate it up to the 7.2 volts?

[tao]

I don't know the process but it's pretty cool..and I am SURE somebody here will be able to explain it for sure!
I thought it interesting to see a little unit with that can step up or down based on the needed output.

[wibblywobbly]

Forgive my stupidity but how could it regulate the voltage up? If the batteries are 7.2 volts and they start to go dead then where is tge voltage going to come from to regulate it up to the 7.2 volts?

It looks as though it is a mini inverter, the sort of thing that you use to run 240v off a 12v car battery. They can step the power up, but there is a reduction in how long the power is supplied for. I used to use one to run a tv in my campervan off the leisure battery.