I’ve acquired several headlamps that have 20 LEDs in a band that stretches across your forehead. Loving the great after-dark visibility!
However, I’d like to replace the 3 x AAA battery pack (includes a pwr switch) with a Lithium pack that could be recharged in-place (would need to add USB or other connector to the plastic battery box for charging, or replace with something else low-profile).
I’ve been poking around looking for a good battery pack and charger ready-to-go, but I’m not finding anything (could be I’m being blind, of course!). Wondering if anyone here either knows of a solution already available, or if not, components I could use from SparkFun to build what I need.
Many thanks!
Deb
(Networking Engineer, good solderer, basic electronics knowledge, nowhere near EE-land!)
I wasn’t sure if sending 5V rather than ~4.5 from 3 x AAAs would cause an issue with the LEDs (short- or long-term). Wasn’t sure if I’d need to add something to drop the voltage. If that .5V difference will not be a problem, that is good to know…thanks.
Ideally I’d use a battery that’s about the same footprint as 3 x AAAs side-by-side, so it could be carried in the same position / holder as the AAAs. Hadn’t found one so far…but I was looking for ~4.5V. if 5V is safe, then that will expand my search options, obviously.
Also ideally, the charging circuitry would be inside the box with the battery, so any USB connection could be used for charging. Not sure if there’s a small foot-print Sparkfun component ready-to-go to do this. If not, I’m 100% up to build one.
I can’t promise that the extra half volt will work and without consequence, just that a USB power bank is where I’d start. A lot of battery powered devices (like your headlamp, probably) are necessarily flexible with regard to input voltage. If you wish to build some packs and can’t find anything suitable [from Sparkfun, here’s a vendor with a large assortment of lithium-polymer cells: [Powerstream LiPo.