A little update... I've been taking a closer look at the light's innards.
The switch is a 3-way clickie, rather than a digital switch. It has 5 contacts, but only 4 of them are used. In the off position, there's no connections. In the two on positions, it makes connections between diagonally opposite contacts. The 5th, unused contact seems to be connected to which ever pair of contacts is active.
The lithium backup circuit is a simple series circuit using a current limiting resistor. I read 42 mA at the tail cap, and 3.2 volts across the emitter which means it's dissipating a little over 1/8 of a watt. The "1 watt LED" claimed on the packaging is off by close to an order of magnitude. Even if you include power lost across the resistor, it's only 1/4 of a watt. :thumbsdow
The rechargeable boost circuit looks fairly simple, though I haven't traced it. By process of elimination, it appears to use a transistor (or some similar looking 3-lead surface-mount component), an inductor, a capacitor, three diodes and a resistor or two.
The solar panel hooks up to the light's common ground contact, to the rechargeable battery's positive line via an anti-drainback diode and to the charge indicator via a resistor. The negative contact of the indicator and battery both connect to common ground, so there's another simple-as-it-gets circuit.
Looks like there are 3 other LED's on the board used as mode/charge indicators.
Yep... little 3 mm units. One amber, one red, one green. I'm tempted to switch the amber (currently indicating that it's using solar power) and green (indicating it's using lithium backup power) around so they better indicate the free-power vs. expensive-power distinction.
some AA Eneloops shrink wrapped up... replace the 2032's with Cr123A's (seems like plenty of room in there)
I don't think you could fit a pair of AAs in this chassis. Maybe if you lined them up end to end, but not side by side like the existing AAAs. You might be able to fit a single '123 in the carrier under the circuit board... they're too fat to fit anywhere else.
use clear silicone sealant on the plastic chassis seams :devil:
Actually, this thing looks pretty water-tight. The body is solidly molded... The lines that look like seams down the side are just artifacts of the molding process. The clickie button rubber is glued down and the end caps are o-ring sealed. The only places that
might have issues are the window plastic for the indicator LEDs and for the solar cells, though the big window looks pretty well sealed up. The indicator windows are probably similarly sealed, but I can't get a clear view inside the body tube.