FIELD FOLLOW UP: 75 Lumen Solar Headlamp

[SargeVining]

https://www.youtube.com/watch?v=a_nSW5jsuKE

[Vegan Packer]

I like that lamp. Did you ultimately find out how long it will burn with both solar and coin batteries? Did you try recharging it with the solar panel, and how long did that take from a pretty much dead light?

[SargeVining]

The coin batteries lasted 2 hours, but those were the ones that came from the factory. I had planned on testing with store bought batteries, but the lamp fell off the pack as I described in the video. My initial solar charge in the first test in the first video was leaving it out from dawn to dusk in unobstructed sunlight. When I took it to the field, I charged it overnight via USB. I got a new one in the mail a couple weeks ago, but haven't yet had any time to test it, but I will do another followup where I drain till dead and test various times of light exposure for endurance.

Another thing I'm curious about is the fact that I now have two of the solar panels and I'd like to see if that speeds up charge as well. I did try to charge a powerbank with one of the panels and got no joy after a dawn to dusk exposure, but will likely try that with the two panels as well.

The biggest test is going to come to see if it conforms to my usage plan, which is to charge via USB before heading out, then use the panel only for charge maintenance after normal night time use. The other problem is going to be designing some form of carriage of the lamp with solar panel installed that eliminates or reduces the chances of one or both components falling off the pack. This thing will be most effective if it can charge during the daytime while hiking.

But right now, with all other things being equal, I'm fairly satisfied that this thing is more than adequate for most weekend recreational backpacking---suitability for long distance or thru hiking is still a bit of a question mark.

[Vegan Packer]

Thanks. Yes, if something like this started off with a full USB charge, and then could be charged enough to fill back up daily while hiking, that would be pretty enticing.

[SargeVining]

Yep. And you've always got 2 hours of backup battery with the coins.