Reddit reviews AOSHIKE 10Pcs 5V 60MA Epoxy Solar Panel Polycrystalline Solar Cell for Solar Battery Charger DIY 68x37MM/2.67x1.45inch (F)

>EDIT: This Mini Solar Panel has a draw of 5V at 60mA at a size 2in2. Surely something like this would have enough power to keep a helmet charged?

Almost certainly not.

Again, you'd need at least 500 mA if that headset charges from USB, I'd assume. It's not just about satisfying the power usage. It's about the charge circuitry in the helmet's headset being 'satisfied' with the power source, as I'm almost certain it's not feeding just 'directly' into a battery. (That'd be horrible. :P)

Aim for a total panel RATING of 5 Watts (remember, Volts x Amps = Watts), and a VOC of ~6 Volts. You may then need a regulator of some sort to ensure the stable 5 Volts for USB charging. Panels will not produce what they're rated for, so you'll get about ~2.5 - 3.0 Watts out of a 5 Watt rated panel (or collection of panels who's total rating is 5 Watts).

There are a lot of different ways you could build this, and it's definitely a cool idea, and I think it's POSSIBLE. Just might not be able to be both good and cheap. XD

There are companies that can make you curved or form-fitting panel sets which could be epoxied to the helmet. I unfortunately don't have any to recommend at the moment, though. :(

Yeah, the cord this is actually the setup I have right now. But it's annoying.

Bulky would definitely be off putting to this, but slow I could handle considering it would always be plugged in, so even when I'm not using the helmet it would be "trickle charging."

Is there a minimum voltage/panel size required to charge the headset? Like you mentioned a garden lamp would have 1.8 volts, what would happen if it was something even less clunky that had, say, an output of 1 volt (25ma)?

A quick look at the technical specification of my headset show that the battery has a charging time of 2.5hrs, I assume this is from a wall outlet using micro USB.

On the other hand, while riding my motorcycle, my current setup runs at 2.1A at 5V and I rode from North Carolina to New York multiple times and it kept my headset at maximum charge just by keeping it plugged in. So following that logic, could a tiny solar panel with a ~1 volt keep the unit charged if it was literally plugged in 24/7.

EDIT: This Mini Solar Panel has a draw of 5V at 60mA at a size 2in^2. Surely something like this would have enough power to keep a helmet charged?