I have just spent several hours reading through about 33 pages of posts. Fascinating stuff and I congratulate you on your dedicated work and loyal customer base. I don't think I've seen a single negative comment in here.
I will be purchasing an 18650 (+16340) model flashlight soon and will need a charger. Leaning towards one of the triple high-current models at this point but not ready to make a decision yet. As I am in (mostly) sunny Australia, I'm off to study your Solar thread before placing an order as I have a collection of LSD AA and AAA cells in constant rotation as well.
One very noob question for you as my electronics knowledge hasn't been exercised for about 20 years. Why is it not possible to put reverse polarity protection into your chargers? I was thinking a simple diode in the charge leads would do it, but then I wondered if this would prevent the voltage meter from working when the unit was not powered? I can't remember anyone in this forum asking the question yet but apologies if you have already covered this somewhere else.
It just seems like a shame that the unit can be wrecked with a simple mistake. I count myself as fairly careful when using chargers but cannot say the same for the kids if they get curious and play with it when I'm not looking.
Also, short-circuit protection? I can't speak for others in here but I would be happy to pay a few dollars more if these features could be added.
Anyway, your thoughts would be appreciated. Keep up the good work.