USB car charger question

Components & Accessories Power
1

Looking at https://www.sparkfun.com/products/16886

I’m interested in running this with a 3 cell li ion pack as input, so down to maybe 9.6 volts as the pack is discharged, or maybe 9 volts if I have to add a diode. It would be for recharging a phone, so probably 1 amp or less, rather than using the full 2.4 amps mentioned on the charger. The blurb says 12-24 volts input but assuming it’s a typical inductive buck converter, I’d like to hope it can run with somewhat less headroom.

Anyone know if this should work? Also, does anyone know if there is a diode inside the charger or if anything bad happens if I accidentally connect it to 12 volts with the wrong polarity?

Finally if the catalog folks see this: I had a hard time finding this adapter through the site search. The magic words are “car charger” but I had looked for 12vdc, cigarette, lighter, terms like that.

Thanks!

2

We haven’t tested these with a lower voltage, I would imagine they will still work with a slightly reduced output current but can’t guarantee that. (You’d need to give it a try and see.)

These most likely do not have any reverse polarity protection since lighter sockets always have the ground on the shell. They may or may not survive reverse polarity, adding an external diode will keep you from accidentally breaking them or you could add a bridge rectifier to the input and then polarity won’t matter at all. :slight_smile: